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Jiao S, Wang K, Luo Y, Zeng J, Han Z. Plastic reorganization of the topological asymmetry of hemispheric white matter networks induced by congenital visual experience deprivation. Neuroimage 2024; 299:120844. [PMID: 39260781 DOI: 10.1016/j.neuroimage.2024.120844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 09/01/2024] [Accepted: 09/08/2024] [Indexed: 09/13/2024] Open
Abstract
Congenital blindness offers a unique opportunity to investigate human brain plasticity. The influence of congenital visual loss on the asymmetry of the structural network remains poorly understood. To address this question, we recruited 21 participants with congenital blindness (CB) and 21 age-matched sighted controls (SCs). Employing diffusion and structural magnetic resonance imaging, we constructed hemispheric white matter (WM) networks using deterministic fiber tractography and applied graph theory methodologies to assess topological efficiency (i.e., network global efficiency, network local efficiency, and nodal local efficiency) within these networks. Statistical analyses revealed a consistent leftward asymmetry in global efficiency across both groups. However, a different pattern emerged in network local efficiency, with the CB group exhibiting a symmetric state, while the SC group showed a leftward asymmetry. Specifically, compared to the SC group, the CB group exhibited a decrease in local efficiency in the left hemisphere, which was caused by a reduction in the nodal properties of some key regions mainly distributed in the left occipital lobe. Furthermore, interhemispheric tracts connecting these key regions exhibited significant structural changes primarily in the splenium of the corpus callosum. This result confirms the initial observation that the reorganization in asymmetry of the WM network following congenital visual loss is associated with structural changes in the corpus callosum. These findings provide novel insights into the neuroplasticity and adaptability of the brain, particularly at the network level.
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Affiliation(s)
- Saiyi Jiao
- National Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
| | - Ke Wang
- National Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China; School of System Science, Beijing Normal University, Beijing 100875, China
| | - Yudan Luo
- National Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China; Department of Psychology and Art Education, Chengdu Education Research Institute, Chengdu 610036, China
| | - Jiahong Zeng
- National Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
| | - Zaizhu Han
- National Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China.
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Demir A, Rosas HD. Altered interhemispheric connectivity in Huntington's Disease. Neuroimage Clin 2024; 44:103670. [PMID: 39293356 PMCID: PMC11422549 DOI: 10.1016/j.nicl.2024.103670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 08/28/2024] [Accepted: 09/06/2024] [Indexed: 09/20/2024]
Abstract
Pyramidal cells give rise to the corpus callosum, interhemispheric fibers that constitute the associations between the left and the right hemispheres. These interconnections are the substrates of important neurological functions, such as perception, memory, emotion, and movement control, which are all affected in Huntington's disease (HD). In this study we used directional tract density patterns (dTDPs) to evaluate changes in interhemispheric connectivity in gene-expanded individuals, which included presymptomatic and early symptomatic HD subjects. Our results demonstrated regionally selective and progressive differences in dTDPs between distinct regions of the corpus callosum (subdivided by Hofer-Frahm scheme) in the gene-expanded cohorts. In the presymptomatic HD cohort, we found trends, such that the density of fibers was reduced in CC regions IIb, III, and IV (p < 0.05); fibers from these regions project to sensory, premotor, and motor cortical regions, respectively. In the HD cohort, we found reduction in the density of fibers in all CC regions, including in fibers extending to the cortical surface (p < 0.002). Our results support the use of dTDPs to evaluate individual and progressive changes in interhemispheric connectivity in HD.
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Affiliation(s)
- Ali Demir
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
| | - H Diana Rosas
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
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Taniguchi K, Kaneko N, Wada M, Moriyama S, Nakajima S, Mimura M, Noda Y. Neurophysiological profiles of patients with bipolar disorders as probed with transcranial magnetic stimulation: A systematic review. Neuropsychopharmacol Rep 2024. [PMID: 38932486 DOI: 10.1002/npr2.12458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 05/13/2024] [Accepted: 05/27/2024] [Indexed: 06/28/2024] Open
Abstract
AIM Bipolar disorder (BD) has a significant impact on global health, yet its neurophysiological basis remains poorly understood. Conventional treatments have limitations, highlighting the need for a better understanding of the neurophysiology of BD for early diagnosis and novel therapeutic strategies. DESIGN Employing a systematic review approach of the PRISMA guidelines, this study assessed the usefulness and validity of transcranial magnetic stimulation (TMS) neurophysiology in patients with BD. METHODS Databases searched included PubMed, MEDLINE, Embase, and PsycINFO, covering studies from January 1985 to January 2024. RESULTS Out of 6597 articles screened, nine studies met the inclusion criteria, providing neurophysiological insights into the pathophysiological basis of BD using TMS-electromyography and TMS-electroencephalography methods. Findings revealed significant neurophysiological impairments in patients with BD compared to healthy controls, specifically in cortical inhibition and excitability. In particular, short-interval cortical inhibition (SICI) was consistently diminished in BD across the studies, which suggests a fundamental impairment of cortical inhibitory function in BD. This systematic review corroborates the potential utility of TMS neurophysiology in elucidating the pathophysiological basis of BD. Specifically, the reduced cortical inhibition in the SICI paradigm observed in patients with BD suggests gamma-aminobutyric acid (GABA)-A receptor-mediated dysfunction, but results from other TMS paradigms have been inconsistent. Thus, complex neurophysiological processes may be involved in the pathological basis underlying BD. This study demonstrated that BD has a neural basis involving impaired GABAergic function, and it is highly expected that further research on TMS neurophysiology will further elucidate the pathophysiological basis of BD.
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Affiliation(s)
- Keita Taniguchi
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Naotsugu Kaneko
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Masataka Wada
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Sotaro Moriyama
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Shinichiro Nakajima
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Masaru Mimura
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Yoshihiro Noda
- Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
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Jiang Y, Chen S, Wu D, He W, Ma X, Zhang L, Zhang Q. Case report: Symmetrical and increased lateral sway-based walking training for patients with corpus callosum infarction: a case series. Front Neurol 2024; 15:1330975. [PMID: 38978808 PMCID: PMC11228249 DOI: 10.3389/fneur.2024.1330975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 05/31/2024] [Indexed: 07/10/2024] Open
Abstract
Introduction Corpus callosum injury is a rare type of injury that occurs after a stroke and can cause lower limb dysfunction and a decrease in activities of daily living ability. Furthermore, there are no studies that focus on the progress in rehabilitation of the lower limb dysfunction caused by infarction in the corpus callosum and the effective treatment plans for this condition. We aimed to present a report of two patients with lower limb dysfunction caused by corpus callosum infarction after a stroke and a walking training method. Methods We implemented a walking training method that prioritizes bilateral symmetry and increases lateral swaying before the patients established sitting/standing balance. The plan is a rapid and effective method for improving walking dysfunction caused by corpus callosum infarction. Case characteristics Following sudden corpus callosum infarction, both patients experienced a significant reduction in lower limb motor function scores and exhibited evident gait disorders. Scale evaluations confirmed that walking training based on symmetrical and increased lateral sway for patients with lower limb motor dysfunction after corpus callosum infarction led to significant symptom improvement. Conclusion We report two cases of sudden motor dysfunction in patients with corpus callosum infarction. Symmetrical and increased lateral sway-based walking training resulted in substantial symptom improvement, as confirmed by scale assessments.
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Affiliation(s)
- Ying Jiang
- Department of Rehabilitation, Jiangsu Zhongshan Geriatric Rehabilitation Hospital, Nanjing, Jiangsu, China
| | - Sijing Chen
- Department of Rehabilitation, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Dan Wu
- Department of Rehabilitation, The Second People's Hospital of Lishui, Lishui, Zhejiang, China
| | - Wei He
- Department of Rehabilitation, Rehabilitation Hospital Affiliated to Nanjing Institute of Physical Education, Wuxi, Jiangsu, China
| | - Xiaoqing Ma
- Department of Rehabilitation, Rehabilitation Hospital Affiliated to Nanjing Institute of Physical Education, Wuxi, Jiangsu, China
| | - Lixia Zhang
- Department of Rehabilitation, The Geriatric Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu, China
| | - Qian Zhang
- Department of Rehabilitation, The Geriatric Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu, China
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Marcantoni I, Piccolantonio G, Ghoushi M, Valenti M, Reversi L, Mariotti F, Foschi N, Lattanzi S, Burattini L, Fabri M, Polonara G. Interhemispheric functional connectivity: an fMRI study in callosotomized patients. Front Hum Neurosci 2024; 18:1363098. [PMID: 38812473 PMCID: PMC11133720 DOI: 10.3389/fnhum.2024.1363098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 04/18/2024] [Indexed: 05/31/2024] Open
Abstract
Introduction Functional connectivity (FC) is defined in terms of temporal correlations between physiological signals, which mainly depend upon structural (axonal) connectivity; it is commonly studied using functional magnetic resonance imaging (fMRI). Interhemispheric FC appears mostly supported by the corpus callosum (CC), although several studies investigating this aspect have not provided conclusive evidence. In this context, patients in whom the CC was resected for therapeutic reasons (split-brain patients) provide a unique opportunity for research into this issue. The present study was aimed at investigating with resting-state fMRI the interhemispheric FC in six epileptic patients who have undergone surgical resection of the CC. Methods The analysis was performed using fMRI of the Brain Software Library; the evaluation of interhemispheric FC and the recognition of the resting-state networks (RSNs) were performed using probabilistic independent component analysis. Results Generally, bilateral brain activation was often observed in primary sensory RSNs, while in the associative areas, such as those composing the default mode and fronto-parietal networks, the activation was often unilateral. Discussion These results suggest that even in the absence of the CC, some interhemispheric communication is still present. This residual FC might be supported through extra-callosal pathways that are likely subcortical, making it possible for some interhemispheric integration. Further studies are needed to confirm these conclusions.
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Affiliation(s)
- Ilaria Marcantoni
- Dipartimento di Ingegneria dell'Informazione, Università Politecnica delle Marche, Ancona, Italy
| | - Giusi Piccolantonio
- Dipartimento di Ingegneria per Medicina di Innovazione, Università di Verona, Verona, Italy
| | - Mojgan Ghoushi
- Dipartimento di Scienze Radiologiche, Azienda Ospedaliera-Universitaria Umberto I, Ancona, Italy
| | - Marco Valenti
- Dipartimento di Scienze Radiologiche, Azienda Ospedaliera-Universitaria Umberto I, Ancona, Italy
| | - Luca Reversi
- Dipartimento di Scienze Radiologiche, Azienda Ospedaliera-Universitaria Umberto I, Ancona, Italy
| | - Francesco Mariotti
- Dipartimento di Scienze Radiologiche, Azienda Ospedaliera-Universitaria Umberto I, Ancona, Italy
| | - Nicoletta Foschi
- Dipartimento di Scienze Neurologiche, Azienda Ospedaliera-Universitaria Umberto I, Ancona, Italy
| | - Simona Lattanzi
- Dipartimento di Medicina Sperimentale e Clinica, Università Politecnica delle Marche, Ancona, Italy
| | - Laura Burattini
- Dipartimento di Ingegneria dell'Informazione, Università Politecnica delle Marche, Ancona, Italy
| | - Mara Fabri
- Dipartimento di Scienze della Vita e dell’Ambiente, Università Politecnica delle Marche, Ancona, Italy
| | - Gabriele Polonara
- Dipartimento di Scienze Cliniche Specialistiche e Odontostomatologiche, Università Politecnica delle Marche, Ancona, Italy
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Xiong Y, Yang L, Wang C, Zhao C, Luo J, Wu D, Ouyang Y, de Thiebaut de Schotten M, Gong G. Cortical mapping of callosal connections in healthy young adults. Hum Brain Mapp 2024; 45:e26629. [PMID: 38379508 PMCID: PMC10879906 DOI: 10.1002/hbm.26629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 01/28/2024] [Accepted: 02/04/2024] [Indexed: 02/22/2024] Open
Abstract
The corpus callosum (CC) is the principal white matter bundle supporting communication between the two brain hemispheres. Despite its importance, a comprehensive mapping of callosal connections is still lacking. Here, we constructed the first bidirectional population-based callosal connectional atlas between the midsagittal section of the CC and the cerebral cortex of the human brain by means of diffusion-weighted imaging tractography. The estimated connectional topographic maps within this atlas have the most fine-grained spatial resolution, demonstrate histological validity, and were reproducible in two independent samples. This new resource, a complete and comprehensive atlas, will facilitate the investigation of interhemispheric communication and come with a user-friendly companion online tool (CCmapping) for easy access and visualization of the atlas.
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Affiliation(s)
- Yirong Xiong
- State Key Laboratory of Cognitive Neuroscience and Learning & IDGMcGovern Institute for Brain ResearchBeijing Normal UniversityBeijingChina
| | - Liyuan Yang
- State Key Laboratory of Cognitive Neuroscience and Learning & IDGMcGovern Institute for Brain ResearchBeijing Normal UniversityBeijingChina
| | - Changtong Wang
- State Key Laboratory of Cognitive Neuroscience and Learning & IDGMcGovern Institute for Brain ResearchBeijing Normal UniversityBeijingChina
| | - Chenxi Zhao
- State Key Laboratory of Cognitive Neuroscience and Learning & IDGMcGovern Institute for Brain ResearchBeijing Normal UniversityBeijingChina
| | - Junhao Luo
- State Key Laboratory of Cognitive Neuroscience and Learning & IDGMcGovern Institute for Brain ResearchBeijing Normal UniversityBeijingChina
| | - Di Wu
- State Key Laboratory of Cognitive Neuroscience and Learning & IDGMcGovern Institute for Brain ResearchBeijing Normal UniversityBeijingChina
| | - Yiping Ouyang
- The Queen's University of Belfast Joint CollegeChina Medical UniversityShenyangChina
| | - Michel de Thiebaut de Schotten
- Brain Connectivity and Behaviour LaboratorySorbonne UniversitéParisFrance
- Groupe d'Imagerie Neurofonctionnelle, Institut des Maladies Neurodégénératives‐UMR 5293, Centre National de la Recherche Scienti que, Commissariat à l'Energie AtomiqueUniversity of BordeauxBordeauxFrance
| | - Gaolang Gong
- State Key Laboratory of Cognitive Neuroscience and Learning & IDGMcGovern Institute for Brain ResearchBeijing Normal UniversityBeijingChina
- Beijing Key Laboratory of Brain Imaging and ConnectomicsBeijing Normal UniversityBeijingChina
- Chinese Institute for Brain ResearchBeijingChina
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Perlow HK, Nalin AP, Ritter AR, Addington M, Ward A, Liu M, Nappi C, Blakaj DM, Beyer SJ, Thomas EM, Grecula JC, Raval RR, Kotecha R, Boulter D, Dawson EL, Zoller W, Palmer JD. Advancing Beyond the Hippocampus to Preserve Cognition for Patients With Brain Metastases: Dosimetric Results From a Phase 2 Trial of Memory-Avoidance Whole Brain Radiation Therapy. Adv Radiat Oncol 2024; 9:101337. [PMID: 38405310 PMCID: PMC10885551 DOI: 10.1016/j.adro.2023.101337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 07/18/2023] [Indexed: 02/27/2024] Open
Abstract
Purpose Recent advances to preserve neurocognitive function in patients treated for brain metastases include stereotactic radiosurgery, hippocampal avoidance whole brain radiation therapy (WBRT), and memantine administration. The hippocampus, corpus callosum, fornix, and amygdala are key neurocognitive substructures with a low propensity for brain metastases. Herein, we report our preliminary experience using a "memory-avoidance" WBRT (MA-WBRT) approach that spares these substructures for patients with >15 brain metastases. Methods and Materials Ten consecutive patients treated with MA-WBRT on a phase 2 clinical trial were reviewed. In each patient, the hippocampi, amygdalae, corpus callosum, and fornix were contoured. Patients were not eligible for MA-WBRT if they had metastases in these substructures. A memory-avoidance region was created using a 5-mm volumetric expansion around these substructures. Hotspots were avoided in the hypothalamus and pituitary gland. Coverage of brain metastases was prioritized over memory avoidance dose constraints. Dose constraints for these avoidance structures included a D100% ≤ 9 Gy and D0.03 cm3 ≤ 16 Gy (variation acceptable to 20 Gy). LINAC-based volumetric modulated arc therapy plans were generated for a prescription dose of 30 Gy in 10 fractions. Results On average, the memory avoidance structure volume was 37.1 cm3 (range, 25.2-44.6 cm3), occupying 2.5% of the entire whole brain target volume. All treatment plans met the D100% dose constraint, and 8 of 10 plans met the D0.03 cm3 constraint, with priority given to tumor coverage for the remaining 2 cases. Target coverage (D98% > 25 Gy) and homogeneity (D2% ≤ 37.5 Gy) were achieved for all plans. Conclusions Modern volumetric modulated arc therapy techniques allow for sparing of the hippocampus, amygdala, corpus callosum, and fornix with good target coverage and homogeneity. After enrollment is completed, quality of life and cognitive data will be evaluated to assess the efficacy of MA-WBRT to mitigate declines in quality of life and cognition after whole brain radiation.
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Affiliation(s)
- Haley K. Perlow
- Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Ansel P. Nalin
- College of Medicine, The Ohio State University, Columbus, Ohio
| | - Alex R. Ritter
- Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Mark Addington
- Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Aubrie Ward
- Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Michal Liu
- Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Collin Nappi
- Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Dukagjin M. Blakaj
- Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Sasha J. Beyer
- Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Evan M. Thomas
- Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - John C. Grecula
- Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Raju R. Raval
- Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Rupesh Kotecha
- Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, Florida
| | - Daniel Boulter
- Department of Radiology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Erica L. Dawson
- Department of Neurology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Wesley Zoller
- Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Joshua D. Palmer
- Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, Ohio
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Adil D, Duerden EG, Eagleson R, de Ribaupierre S. Structural Alterations of the Corpus Callosum in Children With Infantile Hydrocephalus. J Child Neurol 2024; 39:66-76. [PMID: 38387869 PMCID: PMC11083734 DOI: 10.1177/08830738241231343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/17/2024] [Accepted: 01/22/2024] [Indexed: 02/24/2024]
Abstract
This study investigates structural alterations of the corpus callosum in children diagnosed with infantile hydrocephalus. We aim to assess both macrostructural (volume) and microstructural (diffusion tensor imaging metrics) facets of the corpus callosum, providing insights into the nature and extent of alterations associated with this condition. Eighteen patients with infantile hydrocephalus (mean age = 9 years) and 18 age- and sex-matched typically developing healthy children participated in the study. Structural magnetic resonance imaging and diffusion tensor imaging were used to assess corpus callosum volume and microstructure, respectively. Our findings reveal significant alterations in corpus callosum volume, particularly in the posterior area, as well as distinct microstructural disparities, notably pronounced in these same segments. These results highlight the intricate interplay between macrostructural and microstructural aspects in understanding the impact of infantile hydrocephalus. Examining these structural alterations provides an understanding into the mechanisms underlying the effects of infantile hydrocephalus on corpus callosum integrity, given its pivotal role in interhemispheric communication. This knowledge offers a more nuanced perspective on neurologic disorders and underscores the significance of investigating the corpus callosum's health in such contexts.
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Affiliation(s)
- Derya Adil
- Western Institute for Neuroscience, Western University, London, Ontario, Canada
| | - Emma G. Duerden
- Western Institute for Neuroscience, Western University, London, Ontario, Canada
- Applied Psychology, Faculty of Education, Western University, London, Ontario, Canada
| | - Roy Eagleson
- Western Institute for Neuroscience, Western University, London, Ontario, Canada
- Electrical and Computer Engineering, Faculty of Engineering, Western University, London, Ontario, Canada
| | - Sandrine de Ribaupierre
- Western Institute for Neuroscience, Western University, London, Ontario, Canada
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
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Pinto Y, Villa MC, Siliquini S, Polonara G, Passamonti C, Lattanzi S, Foschi N, Fabri M, de Haan EHF. Visual integration across fixation: automatic processes are split but conscious processes remain unified in the split-brain. Front Hum Neurosci 2023; 17:1278025. [PMID: 38021222 PMCID: PMC10667445 DOI: 10.3389/fnhum.2023.1278025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 09/26/2023] [Indexed: 12/01/2023] Open
Abstract
The classic view holds that when "split-brain" patients are presented with an object in the right visual field, they will correctly identify it verbally and with the right hand. However, when the object is presented in the left visual field, the patient verbally states that he saw nothing but nevertheless identifies it accurately with the left hand. This interaction suggests that perception, recognition and responding are separated in the two isolated hemispheres. However, there is now accumulating evidence that this interaction is not absolute; for instance, split-brain patients are able to detect and localise stimuli anywhere in the visual field verbally and with either hand. In this study we set out to explore this cross-hemifield interaction in more detail with the split-brain patient DDC and carried out two experiments. The aim of these experiments is to unveil the unity of deliberate and automatic processing in the context of visual integration across hemispheres. Experiment 1 suggests that automatic processing is split in this context. In contrast, when the patient is forced to adopt a conscious, deliberate, approach, processing seemed to be unified across visual fields (and thus across hemispheres). First, we looked at the confidence that DDC has in his responses. The experiment involved a simultaneous "same" versus "different" matching task with two shapes presented either within one hemifield or across fixation. The results showed that we replicated the observation that split brain patients cannot match across fixation, but more interesting, that DDC was very confident in the across-fixation condition while performing at chance-level. On the basis of this result, we hypothesised a two-route explanation. In healthy subjects, the visual information from the two hemifields is integrated in an automatic, unconscious fashion via the intact splenium, and this route has been severed in DDC. However, we know from previous experiments that some transfer of information remains possible. We proposed that this second route (perhaps less visual; more symbolic) may become apparent when he is forced to use a deliberate, consciously controlled approach. In an experiment where he is informed, by a second stimulus presented in one hemifield, what to do with the first stimulus that was presented in the same or the opposite hemifield, we showed that there was indeed interhemispheric transfer of information. We suggest that this two-route model may help in clarifying some of the controversial issues in split-brain research.
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Affiliation(s)
- Yair Pinto
- Department of Psychology, University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Brain and Cognition (ABC) Center, University of Amsterdam, Amsterdam, Netherlands
| | | | - Sabrina Siliquini
- Child Neuropsychiatry Unit, Marche Polytechnic University, Ancona, Italy
| | - Gabriele Polonara
- Department of Odontostomatologic and Specialized Clinical Sciences, Marche Polytechnic University, Ancona, Italy
| | | | - Simona Lattanzi
- Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy
| | - Nicoletta Foschi
- Epilepsy Center-Neurological Clinic, Azienda “Ospedali Riuniti”, Ancona, Italy
| | - Mara Fabri
- Department of Experimental and Clinical Medicine, Marche Polytechnic University, Ancona, Italy
| | - Edward H. F. de Haan
- Department of Psychology, University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Brain and Cognition (ABC) Center, University of Amsterdam, Amsterdam, Netherlands
- Donders Institute, Radboud University, Nijmegen, Netherlands
- St. Hugh’s College, Oxford University, Oxford, United Kingdom
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Mandine N, Tavernier E, Hülnhagen T, Maréchal B, Kober T, Tauber C, Guichard M, Castelnau P, Morel B. Corpus callosum in children with neurodevelopmental delay: MRI standard qualitative assessment versus automatic quantitative analysis. Eur Radiol Exp 2023; 7:61. [PMID: 37833469 PMCID: PMC10575841 DOI: 10.1186/s41747-023-00375-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 08/07/2023] [Indexed: 10/15/2023] Open
Abstract
BACKGROUND The corpus callosum (CC) is a key brain structure. In children with neurodevelopmental delay, we compared standard qualitative radiological assessments with an automatic quantitative tool. METHODS We prospectively enrolled 73 children (46 males, 63.0%) with neurodevelopmental delay at single university hospital between September 2020 and September 2022. All of them underwent 1.5-T brain magnetic resonance imaging (MRI) including a magnetization-prepared 2 rapid acquisition gradient echoes - MP2RAGE sequence. Two radiologists blindly reviewed the images to classify qualitatively the CC into normal, hypoplasic, hyperplasic, and/or dysgenetic classes. An automatic tool (QuantiFIRE) was used to provide brain volumetry and T1 relaxometry automatically as well as deviations of those parameters compared with a healthy age-matched cohort. The MRI reference standard for CC volumetry was based on the Garel et al. study. Cohen κ statistics was used for interrater agreement. The radiologists and QuantiFIRE's diagnostic accuracy were compared with the reference standard using the Delong test. RESULTS The CC was normal in 42 cases (57.5%), hypoplastic in 20 cases (27.4%), and hypertrophic in 11 cases (15.1%). T1 relaxometry values were abnormal in 26 children (35.6%); either abnormally high (18 cases, 24.6%) or low (8 cases, 11.0%). The interrater Cohen κ coefficient was 0.91. The diagnostic accuracy of the QuantiFIRE prototype was higher than that of the radiologists for hypoplastic and normal CC (p = 0.003 for both subgroups, Delong test). CONCLUSIONS An automated volumetric and relaxometric assessment can assist the evaluation of brain structure such as the CC, particularly in the case of subtle abnormalities. RELEVANCE STATEMENT Automated brain MRI segmentation combined with statistical comparison to normal volume and T1 relaxometry values can be a useful diagnostic support tool for radiologists. KEY POINTS • Corpus callosum abnormality detection is challenging but clinically relevant. • Automated quantitative volumetric analysis had a higher diagnostic accuracy than that of visual appreciation of radiologists. • Quantitative T1 relaxometric analysis might help characterizing corpus callosum better.
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Affiliation(s)
- Natacha Mandine
- Pediatric Radiology Department, CHRU of Tours, Clocheville Hospital, Tours, France
| | - Elsa Tavernier
- Clinical Investigation Center, INSERM 1415, CHRU Tours, Tours, France
| | - Till Hülnhagen
- Advanced Clinical Imaging Technology, Siemens Healthineers International, Lausanne, Switzerland
- Department of Radiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- LTS5, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Bénédicte Maréchal
- Advanced Clinical Imaging Technology, Siemens Healthineers International, Lausanne, Switzerland
- Department of Radiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- LTS5, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Tobias Kober
- Advanced Clinical Imaging Technology, Siemens Healthineers International, Lausanne, Switzerland
- Department of Radiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- LTS5, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Clovis Tauber
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France
| | - Marine Guichard
- Pediatric Neurology Department, CHRU of Tours, Clocheville Hospital, Tours, France
| | - Pierre Castelnau
- Pediatric Neurology Department, CHRU of Tours, Clocheville Hospital, Tours, France
| | - Baptiste Morel
- Pediatric Radiology Department, CHRU of Tours, Clocheville Hospital, Tours, France.
- UMR 1253, iBrain, Université de Tours, Inserm, Tours, France.
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Videtta G, Squarcina L, Rossetti MG, Brambilla P, Delvecchio G, Bellani M. White matter modifications of corpus callosum in bipolar disorder: A DTI tractography review. J Affect Disord 2023; 338:220-227. [PMID: 37301293 DOI: 10.1016/j.jad.2023.06.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 05/08/2023] [Accepted: 06/04/2023] [Indexed: 06/12/2023]
Abstract
BACKGROUND The recent widespread use of diffusion tensor imaging (DTI) tractography allowed researchers to investigate the diffusivity modifications and neuroanatomical changes of white matter (WM) fascicles in major psychiatric disorders, including bipolar disorder (BD). In BD, corpus callosum (CC) seems to have a crucial role in explaining the pathophysiology and cognitive impairment of this psychiatric disorder. This review aims to provide an overview on the latest results emerging from studies that investigated neuroanatomical changes of CC in BD using DTI tractography. METHODS Bibliographic research was conducted on PubMed, Scopus and Web of Science datasets until March 2022. Ten studies fulfilled our inclusion criteria. RESULTS From the reviewed DTI tractography studies a significant decrease of fractional anisotropy emerged in the genu, body and splenium of CC of BD patients compared to controls. This finding is coupled with reduction of fiber density and modification in fiber tract length. Finally, an increase of radial and mean diffusivity in forceps minor and in the entire CC was also reported. LIMITATIONS Small sample size, heterogeneity in terms of methodological (diffusion gradient) and clinical (lifetime comorbidity, BD status, pharmacological treatments) characteristics. CONCLUSIONS Overall, these findings suggest the presence of structural modifications in CC in BD patients, which may in turn explain the cognitive impairments often observed in this psychiatric disorder, especially in executive processing, motor control and visual memory. Finally, structural modifications may suggest an impairment in the amount of functional information and a morphological impact within those brain regions connected by CC.
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Affiliation(s)
- Giovanni Videtta
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Letizia Squarcina
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
| | - Maria Gloria Rossetti
- Department of Neurosciences and Mental Health, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Paolo Brambilla
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy; Department of Neurosciences and Mental Health, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - Giuseppe Delvecchio
- Department of Neurosciences and Mental Health, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy.
| | - Marcella Bellani
- Section of Psychiatry, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
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Tuncer MS, Fekonja LS, Ott S, Pfnür A, Karbe AG, Engelhardt M, Faust K, Picht T, Coburger J, Dührsen L, Vajkoczy P, Onken J. Role of interhemispheric connectivity in recovery from postoperative supplementary motor area syndrome in glioma patients. J Neurosurg 2023; 139:324-333. [PMID: 36461815 DOI: 10.3171/2022.10.jns221303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 10/18/2022] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Surgical resection of gliomas involving the supplementary motor area (SMA) frequently results in SMA syndrome, a symptom complex characterized by transient akinesia and mutism. Because the factors influencing patient functional outcomes after surgery remain elusive, the authors investigated network-based predictors in a multicentric cohort of glioma patients. METHODS The participants were 50 patients treated for glioma located in the SMA at one of the three centers participating in the study. Postoperative functional outcomes (motor deficits, mutism) and duration of symptoms were assessed during hospitalization. Long-term outcome was assessed 3 months after surgery. MRI-based lesion-symptom mapping was performed to estimate the severity of gray matter damage and white matter disconnection. RESULTS The median duration of acute symptoms was 3 days (range 1-42 days). Long-term deficits involving fine motor movements and speech were found at follow-up in 27 patients (54%). Disconnection of the central callosal fibers was associated with prolonged acute symptoms (p < 0.05). Postoperative mutism was significantly related to disconnection severity of the left frontopontine tract, frontal aslant tract, cingulum, and corticostriatal tract (p < 0.05). Disconnection of midposterior callosal fibers and lesion loads within the left medial Brodmann area 4 were associated with long-term motor deficits (p < 0.05). CONCLUSIONS This study provides evidence for the pathophysiology and predictive factors of postoperative SMA syndrome by demonstrating the relation of the disconnection of callosal fibers with prolonged symptom duration (central segment) and long-term motor deficits (midposterior segment). These data may be useful for presurgical risk assessment and adequate consultation for patients prior to undergoing resection of glioma located within the SMA region.
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Affiliation(s)
- Mehmet Salih Tuncer
- 1Department of Neurosurgery, Charité-Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin
| | - Lucius S Fekonja
- 1Department of Neurosurgery, Charité-Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin
- 2Cluster of Excellence: "Matters of Activity. Image Space Material," Humboldt University, Berlin
| | - Stefanie Ott
- 3Department of Neurosurgery, Universitätsklinikum Hamburg-Eppendorf, Hamburg
| | - Andreas Pfnür
- 4Department of Neurosurgery, Universitätsklinikum Ulm, Günzburg
| | - Anna-Gila Karbe
- 1Department of Neurosurgery, Charité-Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin
| | - Melina Engelhardt
- 1Department of Neurosurgery, Charité-Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin
- 5Einstein Center for Neurosciences, Charité-Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin; and
| | - Katharina Faust
- 1Department of Neurosurgery, Charité-Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin
| | - Thomas Picht
- 1Department of Neurosurgery, Charité-Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin
- 2Cluster of Excellence: "Matters of Activity. Image Space Material," Humboldt University, Berlin
- 5Einstein Center for Neurosciences, Charité-Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin; and
| | - Jan Coburger
- 4Department of Neurosurgery, Universitätsklinikum Ulm, Günzburg
| | - Lasse Dührsen
- 3Department of Neurosurgery, Universitätsklinikum Hamburg-Eppendorf, Hamburg
| | - Peter Vajkoczy
- 1Department of Neurosurgery, Charité-Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin
| | - Julia Onken
- 1Department of Neurosurgery, Charité-Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin
- 6German Cancer Consortium (DKTK), Partner Site Berlin, Germany
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Pauwels L, Gooijers J. The Role of the Corpus Callosum (Micro)Structure in Bimanual Coordination: A Literature Review Update. J Mot Behav 2023; 55:525-537. [PMID: 37336516 DOI: 10.1080/00222895.2023.2221985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 05/01/2023] [Accepted: 05/30/2023] [Indexed: 06/21/2023]
Abstract
The characterization of callosal white matter is crucial for understanding the relationship between brain structure and bimanual motor function. An earlier literature review established this. With advancements in neuroimaging and data modeling, we aim to provide an update on the existing literature. Firstly, we highlight new CC parcellation approaches, such as functional MRI- and atlas-informed tractography and in vivo histology. Secondly, we elaborate on recent insights into the CC's role in bimanual coordination, drawing evidence from studies on healthy young and older adults, patients and training-related callosal plasticity. We also reflect on progress in the field and propose future perspectives to inspire research on the underlying mechanisms of structural-functional interactions.
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Affiliation(s)
- Lisa Pauwels
- Department of Movement Sciences, KU Leuven, Movement Control and Neuroplasticity Research Group, Leuven, Belgium
- KU Leuven, Leuven Brain Institute, Department of Movement Sciences, Movement control & Neuroplasticity Research Group, Leuven, Belgium
| | - Jolien Gooijers
- Department of Movement Sciences, KU Leuven, Movement Control and Neuroplasticity Research Group, Leuven, Belgium
- KU Leuven, Leuven Brain Institute, Department of Movement Sciences, Movement control & Neuroplasticity Research Group, Leuven, Belgium
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Vuong A, Joshi SH, Staudt LA, Matsumoto JH, Fowler EG. Improved Myelination following Camp Leg Power, a Selective Motor Control Intervention for Children with Spastic Bilateral Cerebral Palsy: A Diffusion Tensor MRI Study. AJNR Am J Neuroradiol 2023; 44:700-706. [PMID: 37142433 PMCID: PMC10249693 DOI: 10.3174/ajnr.a7860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 04/04/2023] [Indexed: 05/06/2023]
Abstract
BACKGROUND AND PURPOSE Children with spastic cerebral palsy have motor deficits associated with periventricular leukomalacia indicating WM damage to the corticospinal tracts. We investigated whether practice of skilled lower extremity selective motor control movements would elicit neuroplasticity. MATERIALS AND METHODS Twelve children with spastic bilateral cerebral palsy and periventricular leukomalacia born preterm (mean age, 11.5 years; age range, 7.3-16.6 years) participated in a lower extremity selective motor control intervention, Camp Leg Power. Activities promoted isolated joint movement including isokinetic knee exercises, ankle-controlled gaming, gait training, and sensorimotor activities (3 hours/day, 15 sessions, 1 month). DWI scans were collected pre- and postintervention. Tract-Based Spatial Statistics was used to analyze changes in fractional anisotropy, radial diffusivity, axial diffusivity, and mean diffusivity. RESULTS Significantly reduced radial diffusivity (P < . 05) was found within corticospinal tract ROIs, including 28.4% of the left and 3.6% of the right posterior limb of the internal capsule and 14.1% of the left superior corona radiata. Reduced mean diffusivity was found within the same ROIs (13.3%, 11.6%, and 6.6%, respectively). Additionally, decreased radial diffusivity was observed in the left primary motor cortex. Additional WM tracts had decreased radial diffusivity and mean diffusivity, including the anterior limb of the internal capsule, external capsule, anterior corona radiata, and corpus callosum body and genu. CONCLUSIONS Myelination of the corticospinal tracts improved following Camp Leg Power. Neighboring WM changes suggest recruitment of additional tracts involved in regulating neuroplasticity of the motor regions. Intensive practice of skilled lower extremity selective motor control movements promotes neuroplasticity in children with spastic bilateral cerebral palsy.
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Affiliation(s)
- A Vuong
- From the Departments of Bioengineering (A.V., S.H.J.)
- Orthopaedic Surgery (A.V., L.A.S., E.G.F.)
- Center for Cerebral Palsy (A.V., L.A.S., E.G.F.), University of California Los Angeles/Orthopaedic Institute for Children, Los Angeles, California
| | - S H Joshi
- From the Departments of Bioengineering (A.V., S.H.J.)
- Neurology (S.H.J.), Ahmanson Lovelace Brain Mapping Center
| | - L A Staudt
- Orthopaedic Surgery (A.V., L.A.S., E.G.F.)
- Center for Cerebral Palsy (A.V., L.A.S., E.G.F.), University of California Los Angeles/Orthopaedic Institute for Children, Los Angeles, California
| | - J H Matsumoto
- Pediatrics (J.H.M.), University of California Los Angeles, Los Angeles, California
| | - E G Fowler
- Orthopaedic Surgery (A.V., L.A.S., E.G.F.)
- Center for Cerebral Palsy (A.V., L.A.S., E.G.F.), University of California Los Angeles/Orthopaedic Institute for Children, Los Angeles, California
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15
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Hernandez-Pavon JC, Schneider-Garces N, Begnoche JP, Miller LE, Raij T. Targeted Modulation of Human Brain Interregional Effective Connectivity With Spike-Timing Dependent Plasticity. Neuromodulation 2023; 26:745-754. [PMID: 36404214 PMCID: PMC10188658 DOI: 10.1016/j.neurom.2022.10.045] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 09/23/2022] [Accepted: 10/04/2022] [Indexed: 11/19/2022]
Abstract
OBJECTIVE The ability to selectively up- or downregulate interregional brain connectivity would be useful for research and clinical purposes. Toward this aim, cortico-cortical paired associative stimulation (ccPAS) protocols have been developed in which two areas are repeatedly stimulated with a millisecond-level asynchrony. However, ccPAS results in humans using bifocal transcranial magnetic stimulation (TMS) have been variable, and the mechanisms remain unproven. In this study, our goal was to test whether ccPAS mechanism is spike-timing-dependent plasticity (STDP). MATERIALS AND METHODS Eleven healthy participants received ccPAS to the left primary motor cortex (M1) → right M1 with three different asynchronies (5 milliseconds shorter, equal to, or 5 milliseconds longer than the 9-millisecond transcallosal conduction delay) in separate sessions. To observe the neurophysiological effects, single-pulse TMS was delivered to the left M1 before and after ccPAS while cortico-cortical evoked responses were extracted from the contralateral M1 using source-resolved electroencephalography. RESULTS Consistent with STDP mechanisms, the effects on synaptic strengths flipped depending on the asynchrony. Further implicating STDP, control experiments suggested that the effects were unidirectional and selective to the targeted connection. CONCLUSION The results support the idea that ccPAS induces STDP and may selectively up- or downregulate effective connectivity between targeted regions in the human brain.
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Affiliation(s)
- Julio C Hernandez-Pavon
- Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; Center for Brain Stimulation, Shirley Ryan AbilityLab, Chicago, IL, USA; Legs + Walking Lab, Shirley Ryan AbilityLab, Chicago, IL, USA
| | | | | | - Lee E Miller
- Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, USA; Limb Motor Control Lab, Shirley Ryan AbilityLab, Chicago, IL, USA
| | - Tommi Raij
- Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; Center for Brain Stimulation, Shirley Ryan AbilityLab, Chicago, IL, USA; Department of Neurobiology, Weinberg College of Arts and Sciences, Northwestern University, Evanston, IL, USA.
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Wróbel PP, Guder S, Feldheim JF, Graterol Pérez JA, Frey BM, Choe CU, Bönstrup M, Cheng B, Rathi Y, Pasternak O, Thomalla G, Gerloff C, Shenton ME, Schulz R. Altered microstructure of the contralesional ventral premotor cortex and motor output after stroke. Brain Commun 2023; 5:fcad160. [PMID: 37265601 PMCID: PMC10231803 DOI: 10.1093/braincomms/fcad160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 03/17/2023] [Accepted: 05/15/2023] [Indexed: 06/03/2023] Open
Abstract
Cortical thickness analyses have provided valuable insights into changes in cortical brain structure after stroke and their association with recovery. Across studies though, relationships between cortical structure and function show inconsistent results. Recent developments in diffusion-weighted imaging of the cortex have paved the way to uncover hidden aspects of stroke-related alterations in cortical microstructure, going beyond cortical thickness as a surrogate for cortical macrostructure. We re-analysed clinical and imaging data of 42 well-recovered chronic stroke patients from 2 independent cohorts (mean age 64 years, 4 left-handed, 71% male, 16 right-sided strokes) and 33 healthy controls of similar age and gender. Cortical fractional anisotropy and cortical thickness values were obtained for six key sensorimotor areas of the contralesional hemisphere. The regions included the primary motor cortex, dorsal and ventral premotor cortex, supplementary and pre-supplementary motor areas, and primary somatosensory cortex. Linear models were estimated for group comparisons between patients and controls and for correlations between cortical fractional anisotropy and cortical thickness and clinical scores. Compared with controls, stroke patients exhibited a reduction in fractional anisotropy in the contralesional ventral premotor cortex (P = 0.005). Fractional anisotropy of the other regions and cortical thickness did not show a comparable group difference. Higher fractional anisotropy of the ventral premotor cortex, but not cortical thickness, was positively associated with residual grip force in the stroke patients. These data provide novel evidence that the contralesional ventral premotor cortex might constitute a key sensorimotor area particularly susceptible to stroke-related alterations in cortical microstructure as measured by diffusion MRI and they suggest a link between these changes and residual motor output after stroke.
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Affiliation(s)
- Paweł P Wróbel
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
| | - Stephanie Guder
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
| | - Jan F Feldheim
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
| | - José A Graterol Pérez
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
| | - Benedikt M Frey
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
| | - Chi-un Choe
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
| | - Marlene Bönstrup
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
- Department of Neurology, University Medical Center, Leipzig 04103, Germany
| | - Bastian Cheng
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
| | - Yogesh Rathi
- Psychiatry Neuroimaging Laboratory, Brigham and Women’s Hospital, Harvard Medical School, Boston 02115, MA, USA
- Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston 02115, MA, USA
| | - Ofer Pasternak
- Psychiatry Neuroimaging Laboratory, Brigham and Women’s Hospital, Harvard Medical School, Boston 02115, MA, USA
- Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston 02115, MA, USA
| | - Götz Thomalla
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
| | - Christian Gerloff
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
| | - Martha E Shenton
- Psychiatry Neuroimaging Laboratory, Brigham and Women’s Hospital, Harvard Medical School, Boston 02115, MA, USA
- Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School, Boston 02115, MA, USA
| | - Robert Schulz
- Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg 20251, Germany
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Andrushko JW, Levenstein JM, Zich C, Edmond EC, Campbell J, Clarke WT, Emir U, Farthing JP, Stagg CJ. Repeated unilateral handgrip contractions alter functional connectivity and improve contralateral limb response times. Sci Rep 2023; 13:6437. [PMID: 37081073 PMCID: PMC10119116 DOI: 10.1038/s41598-023-33106-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 04/07/2023] [Indexed: 04/22/2023] Open
Abstract
In humans, motor learning is underpinned by changes in sensorimotor network functional connectivity (FC). Unilateral contractions increase FC in the ipsilateral primary motor cortex (M1) and supplementary motor area (SMA); areas involved in motor planning and execution of the contralateral hand. Therefore, unilateral contractions are a promising approach to augment motor performance in the contralateral hand. In a within-participant, randomized, cross-over design, 15 right-handed adults had two magnetic resonance imaging (MRI) sessions, where functional-MRI and MR-Spectroscopic Imaging were acquired before and after repeated right-hand contractions at either 5% or 50% maximum voluntary contraction (MVC). Before and after scanning, response times (RTs) were determined in both hands. Nine minutes of 50% MVC contractions resulted in decreased handgrip force in the contracting hand, and decreased RTs and increased handgrip force in the contralateral hand. This improved motor performance in the contralateral hand was supported by significant neural changes: increased FC between SMA-SMA and increased FC between right M1 and right Orbitofrontal Cortex. At a neurochemical level, the degree of GABA decline in left M1, left and right SMA correlated with subsequent behavioural improvements in the left-hand. These results support the use of repeated handgrip contractions as a potential modality for improving motor performance in the contralateral hand.
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Affiliation(s)
- Justin W Andrushko
- College of Kinesiology, University of Saskatchewan, Saskatoon, Canada.
- FMRIB, Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK.
| | - Jacob M Levenstein
- FMRIB, Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
- Section on Functional Imaging Methods, National Institutes of Mental Health, National Institutes of Health, Bethesda, MD, USA
- Thompson Institute, University of the Sunshine Coast, Sippy Downs, Australia
| | - Catharina Zich
- FMRIB, Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
- Department of Clinical and Movement Neurosciences, University College London, London, UK
| | - Evan C Edmond
- FMRIB, Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | - Jon Campbell
- FMRIB, Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | - William T Clarke
- FMRIB, Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | - Uzay Emir
- School of Health Sciences, College of Health and Human Sciences, Purdue University, West Lafayette, USA
| | | | - Charlotte J Stagg
- FMRIB, Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
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Fabri M, Polonara G. Functional topography of the corpus callosum as revealed by fMRI and behavioural studies of control subjects and patients with callosal resection. Neuropsychologia 2023; 183:108533. [PMID: 36906223 DOI: 10.1016/j.neuropsychologia.2023.108533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 01/26/2023] [Accepted: 03/05/2023] [Indexed: 03/12/2023]
Abstract
The concept of a topographical map of the corpus callosum (CC), the main interhemispheric commissure, has emerged from human lesion studies and from anatomical tracing investigations in other mammals. Over the last few years, a rising number of researchers have been reporting functional magnetic resonance imaging (fMRI) activation in also the CC. This short review summarizes the functional and behavioral studies performed in groups of healthy subjects and in patients undergone to partial or total callosal resection, and it is focused on the work conducted by the authors. Functional data have been collected by diffusion tensor imaging and tractography (DTI and DTT) and functional magnetic resonance imaging (fMRI), both techniques allowing to expand and refine our knowledge of the commissure. Neuropsychological test were also administered, and simple behavioral task, as imitation perspective and mental rotation ability, were analyzed. These researches added new insight on the topographic organization of the human CC. By combining DTT and fMRI it was possible to observe that the callosal crossing points of interhemispheric fibers connecting homologous primary sensory cortices, correspond to the CC sites where the fMRI activation elicited by peripheral stimulation was detected. In addition, CC activation during imitation and mental rotation performance was also reported. These studies demonstrated the presence of specific callosal fiber tracts that cross the commissure in the genu, body, and splenium, at sites showing fMRI activation, consistently with cortical activated areas. Altogether, these findings lend further support to the notion that the CC displays a functional topographic organization, also related to specific behavior.
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Affiliation(s)
- Mara Fabri
- Dipartimento di Scienze Della Vita e Dell'Ambiente, Università Politecnica Delle Marche, Via Brecce Bianche, 60131, Ancona, Italy.
| | - Gabriele Polonara
- Dipartimento di Scienze Cliniche Specialistiche e Odontostomatologiche, Università Politecnica Delle Marche, Via Tronto 10/A, 60020, Ancona, Italy.
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Gao T, Hu Y, Zhuang J, Bai Y, Lu R. Repetitive Transcranial Magnetic Stimulation of the Brain Region Activated by Motor Imagery Involving a Paretic Wrist and Hand for Upper-Extremity Motor Improvement in Severe Stroke: A Preliminary Study. Brain Sci 2022; 13:69. [PMID: 36672050 PMCID: PMC9856429 DOI: 10.3390/brainsci13010069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 12/14/2022] [Accepted: 12/25/2022] [Indexed: 12/31/2022] Open
Abstract
Approximately two-thirds of stroke survivors experience chronic upper-limb paresis; however, treatment options are limited. Repetitive transcranial magnetic stimulation (rTMS) can enhance motor function recovery in stroke survivors, but its efficacy is controversial. We compared the efficacy of stimulating different targets in 10 chronic stroke patients with severe upper-limb motor impairment. Motor imagery-based brain-computer interface training augmented with virtual reality was used to induce neural activity in the brain region during an imagery task. Participants were then randomly assigned to two groups: an experimental group (received high-frequency rTMS delivered to the brain region activated earlier) and a comparison group (received low-frequency rTMS delivered to the contralesional primary motor cortex). Behavioural metrics and diffusion tensor imaging were compared pre- and post rTMS. After the intervention, participants in both groups improved somewhat. This preliminary study indicates that in chronic stroke patients with severe upper-limb motor impairment, inducing activation in specific brain regions during motor imagery tasks and selecting these regions as a target is feasible. Further studies are needed to explore the efficacy of this intervention.
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Affiliation(s)
- Tianhao Gao
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Yiqian Hu
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Jie Zhuang
- School of Psychology, Shanghai University of Sport, Shanghai 200438, China
| | - Yulong Bai
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai 200040, China
- National Center for Neurological Disorders, Shanghai 200040, China
| | - Rongrong Lu
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai 200040, China
- National Center for Neurological Disorders, Shanghai 200040, China
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Isiklar S, Ozdemir ST, Ozkaya G, Ozpar R. Three dimensional development and asymmetry of the corpus callosum in the 0-18 age group: A retrospective magnetic resonance imaging study. Clin Anat 2022; 36:581-598. [PMID: 36527384 DOI: 10.1002/ca.23996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 12/07/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
Most of the corpus callosum (CC) developmental studies are concerned with its two-dimensional structure. Linear and area measurements do not directly assess the CC size but estimate the overall structure from the cross-sectional image. This study investigated age- and sex-related changes in volumetric development and asymmetry of CC from birth to 18. For this retrospective study, we selected 696 patients (329 [47.27%] females) with both 3D-T1-weighted sequence and normal radiological anatomy from patients 0-18 years of age who had brain magnetic resonance imaging (MRI) between 2012 and 2020. The genu, body, splenium, and total volume of CC were calculated using MRICloud. The measurement results of 23 age groups were analyzed with SPSS (ver.28). Total CC volume was 18740.76 ± 4314.06 mm3 between 0 and 18 years of age, and its ratio to total brain volume (TBV) was 1.70% ± 0.23%. We observed that the total CC volume has six developmental periods 0 years, 1, 2-4, 5-9, 10-16, and 17-18 years. Genu and body grew in five developmental periods, while splenium in seven. There was intermittent sexual dimorphism in the CC volume in the first 4 years of life (p < 0.05). However, sex factor was insignificant in CC ratio to TBV. Total CC was right lateralized on average 1.81% (ranging -0.59% to 4.52%). Genu was 8.70% lateralized to the right, the body was 2.99% to the left, and the splenium was 1.41% to the right. The three-dimensional development of CC agreed with the two-dimensional developmental data of CC except for some differences.
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Affiliation(s)
- Sefa Isiklar
- Medical Imaging Techniques Program, Vocational School of Health Services, Bursa Uludag University, Bursa, Turkey
| | - Senem Turan Ozdemir
- Department of Anatomy, Faculty of Medicine, Bursa Uludag University, Bursa, Turkey
| | - Güven Ozkaya
- Department of Biostatistics, Faculty of Medicine, Bursa Uludag University, Bursa, Turkey
| | - Rıfat Ozpar
- Department of Radiology, Faculty of Medicine, Bursa Uludag University, Bursa, Turkey
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21
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Lanna M, Scelsa B, Cutillo G, Amendolara M, Doneda C, Balestriero M, Faiola S, Casati D, Spaccini L, Cetin I. Long-term outcome of consecutive case series of congenital isolated agenesis of corpus callosum. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2022; 60:494-498. [PMID: 35274783 DOI: 10.1002/uog.24898] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/22/2022] [Accepted: 02/25/2022] [Indexed: 06/14/2023]
Abstract
OBJECTIVE To describe the long-term outcome of children with prenatally diagnosed isolated complete agenesis of the corpus callosum (cACC). METHODS In this single-center case series, we reviewed retrospectively the charts of fetuses referred to our fetal therapy unit from January 2004 to July 2020 for a suspected anomaly of the corpus callosum (CC). Cases with prenatally diagnosed isolated cACC were included. Fetal karyotype and comparative genomic hybridization microarray of amniotic fluid, in addition to fetal magnetic resonance imaging, were offered to all pregnant women with a diagnosis of fetal CC malformation. The surviving children were enrolled in the neurodevelopmental follow-up program at our institution, which included postnatal magnetic resonance imaging, serial neurological examinations and neurodevelopmental evaluations with standardized tests according to age. Families living in remote areas or far from our institution were offered a structured ad-hoc phone interview. RESULTS A total of 128 pregnancies with fetal CC malformation were identified (mean gestational age at diagnosis, 24.5 (range, 21-34) weeks), of which 53 cases were diagnosed prenatally with apparently isolated cACC. Of these, 12 cases underwent termination of pregnancy, one resulted in intrauterine demise at 24 weeks of gestation and 13 cases were lost to follow-up. Of the remaining 27 children, one was excluded due to an associated chromosomal anomaly (8p21.3q11.21 mosaic duplication) diagnosed after birth, which could have been detected prenatally if the parents had consented to amniocentesis. In the 26 children included in the analysis, neurodevelopmental follow-up was available for a median of 3 (range, 1-16) years. Three (11.5%) infants had severe neurodevelopmental impairment, two of which were diagnosed postnatally with a genetic syndrome (Mowat-Wilson syndrome and Vici syndrome) that would not have been diagnosed prenatally. Seven (26.9%) children had mild neurodevelopmental impairment and 16 (61.5%) had normal neurodevelopmental outcome. The Full-Scale Intelligence Quotients of the three children with severe neurodevelopmental impairment were 50, 64 and 63, respectively, while that of the remaining children was in the normal range (median, 101; range, 89-119). CONCLUSIONS In 88% of the children with cACC included in this study, neurodevelopment was not severely impaired. However, long-term follow-up is recommended in all cases of congenital isolated cACC to recognize subtle neurodevelopmental disorders as early as possible. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.
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Affiliation(s)
- M Lanna
- Fetal Therapy Unit 'U. Nicolini', Vittore Buzzi Children's Hospital, Milan, Italy
- Department of Women, Mother and Neonate, Vittore Buzzi Children's Hospital, University of Milan, Milan, Italy
| | - B Scelsa
- Department of Pediatric Neurology, Vittore Buzzi Children's Hospital, University of Milan, Milan, Italy
| | - G Cutillo
- Department of Pediatric Neurology, Vittore Buzzi Children's Hospital, University of Milan, Milan, Italy
| | - M Amendolara
- Department of Women, Mother and Neonate, Vittore Buzzi Children's Hospital, University of Milan, Milan, Italy
| | - C Doneda
- Department of Radiology and Neuroradiology, Vittore Buzzi Children's Hospital, University of Milan, Milan, Italy
| | - M Balestriero
- Department of Pediatric Neurology, Vittore Buzzi Children's Hospital, University of Milan, Milan, Italy
| | - S Faiola
- Fetal Therapy Unit 'U. Nicolini', Vittore Buzzi Children's Hospital, Milan, Italy
- Department of Women, Mother and Neonate, Vittore Buzzi Children's Hospital, University of Milan, Milan, Italy
| | - D Casati
- Fetal Therapy Unit 'U. Nicolini', Vittore Buzzi Children's Hospital, Milan, Italy
- Department of Women, Mother and Neonate, Vittore Buzzi Children's Hospital, University of Milan, Milan, Italy
| | - L Spaccini
- Clinical Genetic Service, Vittore Buzzi Children's Hospital, University of Milan, Milan, Italy
| | - I Cetin
- Department of Women, Mother and Neonate, Vittore Buzzi Children's Hospital, University of Milan, Milan, Italy
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22
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The impact of brain lesion characteristics and the corticospinal tract wiring on mirror movements in unilateral cerebral palsy. Sci Rep 2022; 12:16301. [PMID: 36175439 PMCID: PMC9522771 DOI: 10.1038/s41598-022-19920-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 09/06/2022] [Indexed: 11/21/2022] Open
Abstract
Mirror movements (MM) influence bimanual performance in children with unilateral cerebral palsy (uCP). Whilst MM are related to brain lesion characteristics and the corticospinal tract (CST) wiring pattern, the combined impact of these neurological factors remains unknown. Forty-nine children with uCP (mean age 10y6mo) performed a repetitive squeezing task to quantify similarity (MM-similarity) and strength (MM-intensity) of the MM activity. We used MRI data to evaluate lesion type (periventricular white matter, N = 30; cortico-subcortical, N = 19), extent of ipsilesional damage, presence of bilateral lesions, and damage to basal ganglia, thalamus and corpus callosum. The CST wiring was assessed with Transcranial Magnetic Stimulation (17 CSTcontralateral, 16 CSTipsilateral, 16 CSTbilateral). Data was analyzed with regression analyses. In the more-affected hand, MM-similarity and intensity were higher with CSTbilateral/ipsilateral. In the less-affected hand, MM-similarity was higher in children with (1) CSTcontra with CSC lesions, (2) CSTbilat/ipsi with PVL lesions and (3) CSTbilat/ipsi with unilateralized lesions. MM-intensity was higher with larger damage to the corpus callosum and unilateral lesions. A complex combination of neurological factors influences MM characteristics, and the mechanisms differ between hands.
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23
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Siebner HR, Funke K, Aberra AS, Antal A, Bestmann S, Chen R, Classen J, Davare M, Di Lazzaro V, Fox PT, Hallett M, Karabanov AN, Kesselheim J, Beck MM, Koch G, Liebetanz D, Meunier S, Miniussi C, Paulus W, Peterchev AV, Popa T, Ridding MC, Thielscher A, Ziemann U, Rothwell JC, Ugawa Y. Transcranial magnetic stimulation of the brain: What is stimulated? - A consensus and critical position paper. Clin Neurophysiol 2022; 140:59-97. [PMID: 35738037 PMCID: PMC9753778 DOI: 10.1016/j.clinph.2022.04.022] [Citation(s) in RCA: 139] [Impact Index Per Article: 69.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 03/14/2022] [Accepted: 04/15/2022] [Indexed: 12/11/2022]
Abstract
Transcranial (electro)magnetic stimulation (TMS) is currently the method of choice to non-invasively induce neural activity in the human brain. A single transcranial stimulus induces a time-varying electric field in the brain that may evoke action potentials in cortical neurons. The spatial relationship between the locally induced electric field and the stimulated neurons determines axonal depolarization. The induced electric field is influenced by the conductive properties of the tissue compartments and is strongest in the superficial parts of the targeted cortical gyri and underlying white matter. TMS likely targets axons of both excitatory and inhibitory neurons. The propensity of individual axons to fire an action potential in response to TMS depends on their geometry, myelination and spatial relation to the imposed electric field and the physiological state of the neuron. The latter is determined by its transsynaptic dendritic and somatic inputs, intrinsic membrane potential and firing rate. Modeling work suggests that the primary target of TMS is axonal terminals in the crown top and lip regions of cortical gyri. The induced electric field may additionally excite bends of myelinated axons in the juxtacortical white matter below the gyral crown. Neuronal excitation spreads ortho- and antidromically along the stimulated axons and causes secondary excitation of connected neuronal populations within local intracortical microcircuits in the target area. Axonal and transsynaptic spread of excitation also occurs along cortico-cortical and cortico-subcortical connections, impacting on neuronal activity in the targeted network. Both local and remote neural excitation depend critically on the functional state of the stimulated target area and network. TMS also causes substantial direct co-stimulation of the peripheral nervous system. Peripheral co-excitation propagates centrally in auditory and somatosensory networks, but also produces brain responses in other networks subserving multisensory integration, orienting or arousal. The complexity of the response to TMS warrants cautious interpretation of its physiological and behavioural consequences, and a deeper understanding of the mechanistic underpinnings of TMS will be critical for advancing it as a scientific and therapeutic tool.
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Affiliation(s)
- Hartwig R Siebner
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Neurology, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark; Institute for Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.
| | - Klaus Funke
- Department of Neurophysiology, Medical Faculty, Ruhr-University Bochum, Bochum, Germany
| | - Aman S Aberra
- Department of Biomedical Engineering, Duke University, Durham, NC, USA
| | - Andrea Antal
- Department of Clinical Neurophysiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Sven Bestmann
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom; Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Robert Chen
- Krembil Brain Institute, University Health Network and Division of Neurology, University of Toronto, Toronto, Ontario, Canada
| | - Joseph Classen
- Department of Neurology, University of Leipzig, Leipzig, Germany
| | - Marco Davare
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom; Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Vincenzo Di Lazzaro
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, Università Campus Bio-Medico di Roma, via Álvaro del Portillo 21, 00128 Rome, Italy
| | - Peter T Fox
- Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Mark Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Anke N Karabanov
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Nutrition and Exercise, University of Copenhagen, Copenhagen, Denmark
| | - Janine Kesselheim
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Mikkel M Beck
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Giacomo Koch
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy; Non-invasive Brain Stimulation Unit, Laboratorio di NeurologiaClinica e Comportamentale, Fondazione Santa Lucia IRCCS, Rome, Italy
| | - David Liebetanz
- Department of Clinical Neurophysiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Sabine Meunier
- Sorbonne Université, Faculté de Médecine, INSERM U 1127, CNRS 4 UMR 7225, Institut du Cerveau, F-75013, Paris, France
| | - Carlo Miniussi
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Italy; Cognitive Neuroscience Section, IRCCS Centro San Giovanni di DioFatebenefratelli, Brescia, Italy
| | - Walter Paulus
- Department of Clinical Neurophysiology, University Medical Center, Georg-August-University, Göttingen, Germany
| | - Angel V Peterchev
- Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Psychiatry & Behavioral Sciences, School of Medicine, Duke University, Durham, NC, USA; Department of Electrical & Computer Engineering, Duke University, Durham, NC, USA; Department of Neurosurgery, School of Medicine, Duke University, Durham, NC, USA
| | - Traian Popa
- Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland; Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), Swiss Federal Institute of Technology (EPFL Valais), Clinique Romande de Réadaptation, Sion, Switzerland
| | - Michael C Ridding
- University of South Australia, IIMPACT in Health, Adelaide, Australia
| | - Axel Thielscher
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark; Department of Health Technology, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Ulf Ziemann
- Department of Neurology & Stroke, University Tübingen, Tübingen, Germany; Hertie Institute for Clinical Brain Research, University Tübingen, Tübingen, Germany
| | - John C Rothwell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Yoshikazu Ugawa
- Department of Neurology, Fukushima Medical University, Fukushima, Japan; Fukushima Global Medical Science Centre, Advanced Clinical Research Centre, Fukushima Medical University, Fukushima, Japan
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24
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West SL, Aronson JD, Popa LS, Feller KD, Carter RE, Chiesl WM, Gerhart ML, Shekhar AC, Ghanbari L, Kodandaramaiah SB, Ebner TJ. Wide-Field Calcium Imaging of Dynamic Cortical Networks during Locomotion. Cereb Cortex 2022; 32:2668-2687. [PMID: 34689209 PMCID: PMC9201596 DOI: 10.1093/cercor/bhab373] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 09/10/2021] [Accepted: 09/11/2021] [Indexed: 01/04/2023] Open
Abstract
Motor behavior results in complex exchanges of motor and sensory information across cortical regions. Therefore, fully understanding the cerebral cortex's role in motor behavior requires a mesoscopic-level description of the cortical regions engaged, their functional interactions, and how these functional interactions change with behavioral state. Mesoscopic Ca2+ imaging through transparent polymer skulls in mice reveals elevated activation of the dorsal cerebral cortex during locomotion. Using the correlations between the time series of Ca2+ fluorescence from 28 regions (nodes) obtained using spatial independent component analysis (sICA), we examined the changes in functional connectivity of the cortex from rest to locomotion with a goal of understanding the changes to the cortical functional state that facilitate locomotion. Both the transitions from rest to locomotion and from locomotion to rest show marked increases in correlation among most nodes. However, once a steady state of continued locomotion is reached, many nodes, including primary motor and somatosensory nodes, show decreases in correlations, while retrosplenial and the most anterior nodes of the secondary motor cortex show increases. These results highlight the changes in functional connectivity in the cerebral cortex, representing a series of changes in the cortical state from rest to locomotion and on return to rest.
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Affiliation(s)
- Sarah L West
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
| | - Justin D Aronson
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
| | - Laurentiu S Popa
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
| | - Kathryn D Feller
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
- Union College Biological Sciences Department, Schenectady, NY 12308, USA
| | - Russell E Carter
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
| | - William M Chiesl
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
| | - Morgan L Gerhart
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
| | - Aditya C Shekhar
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
| | - Leila Ghanbari
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Suhasa B Kodandaramaiah
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
| | - Timothy J Ebner
- Department of Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, MN 55455, USA
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25
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Zhang R, Tam SKTS, Wong NML, Wu J, Tao J, Chen L, Lin K, Lee TMC. Aberrant functional metastability and structural connectivity are associated with rumination in individuals with major depressive disorder. Neuroimage Clin 2022; 33:102916. [PMID: 34923200 PMCID: PMC8693354 DOI: 10.1016/j.nicl.2021.102916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 11/30/2021] [Accepted: 12/13/2021] [Indexed: 11/23/2022]
Abstract
Higher synchrony and lower metastability in adults with higher levels of rumination. Prefrontal white matter integrity deficits are also associated with rumination. Most prominent aberrations were found in the genu of the corpus callosum. Structural connectivity as the basis between dynamic connectivity and rumination. New outlook on altered structural integrity and metastability subserving rumination.
Rumination is a repetitive and compulsive thinking focusing on oneself, and the nature and consequences of distress. It is a core characteristic in psychiatric disorders characterized by affective dysregulation, and emerging evidence suggests that rumination is associated with aberrant dynamic functional connectivity and structural connectivity. However, the underlying neural mechanisms remain poorly understood. Here, we adopted a multimodal approach and tested the hypothesis that white matter connectivity forms the basis of the implications of temporal dynamics of functional connectivity in the rumination trait. Fifty-three depressed and ruminative individuals and a control group of 47 age- and gender-matched individuals with low levels of rumination underwent resting-state fMRI and diffusion tensor imaging. We found that lower global metastability and higher global synchrony of the dynamic functional connectivity were associated with higher levels of rumination. Specifically, the altered global synchrony and global metastability mediated the association between white matter integrity of the genu of the corpus callosum to rumination. Hence, our findings offered the first line of evidence for the intricate role of (sub)optimal transition of functional brain states in the connection of structural brain connectivity in ruminative thinking.
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Affiliation(s)
- Ruibin Zhang
- Laboratory of Cognitive Control and Brain Healthy, Department of Psychology, School of Public Health, Southern Medical University, Department of Psychiatry, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Sammi-Kenzie T S Tam
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China; Laboratory of Neuropsychology and Human Neuroscience, The University of Hong Kong, Hong Kong, China
| | - Nichol M L Wong
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China; Laboratory of Neuropsychology and Human Neuroscience, The University of Hong Kong, Hong Kong, China.
| | - Jingsong Wu
- Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Jing Tao
- Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Lidian Chen
- Fujian University of Traditional Chinese Medicine, Fuzhou, China
| | - Kangguang Lin
- Department of Affective Disorders, Guangzhou Huiai Hospital, The Affiliated Brain Hospital of Guangzhou Medical University, China.
| | - Tatia M C Lee
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China; Laboratory of Neuropsychology and Human Neuroscience, The University of Hong Kong, Hong Kong, China; Institute of Clinical Neuropsychology, The University of Hong Kong, Hong Kong, China.
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26
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Momi D, Ozdemir RA, Tadayon E, Boucher P, Di Domenico A, Fasolo M, Shafi MM, Pascual-Leone A, Santarnecchi E. Phase-dependent local brain states determine the impact of image-guided transcranial magnetic stimulation on motor network electroencephalographic synchronization. J Physiol 2022; 600:1455-1471. [PMID: 34799873 PMCID: PMC9728936 DOI: 10.1113/jp282393] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 11/10/2021] [Indexed: 11/08/2022] Open
Abstract
Recent studies have synchronized transcranial magnetic stimulation (TMS) application with pre-defined brain oscillatory phases showing how brain response to perturbation depends on the brain state. However, none have investigated whether phase-dependent TMS can possibly modulate connectivity with homologous distant brain regions belonging to the same network. In the framework of network-targeted TMS, we investigated whether stimulation delivered at a specific phase of ongoing brain oscillations might favour stronger cortico-cortical (c-c) synchronization of distant network nodes connected to the stimulation target. Neuronavigated TMS pulses were delivered over the primary motor cortex (M1) during ongoing electroencephalography recording in 24 healthy individuals over two repeated sessions 1 month apart. Stimulation effects were analysed considering whether the TMS pulse was delivered at the time of a positive (peak) or negative (trough) phase of μ-frequency oscillation, which determines c-c synchrony within homologous areas of the sensorimotor network. Diffusion weighted imaging was used to study c-c connectivity within the sensorimotor network and identify contralateral regions connected with the stimulation spot. Depending on when during the μ-activity the TMS-pulse was applied (peak or trough), its impact on inter-hemispheric network synchrony varied significantly. Higher M1-M1 phase-lock synchronization after the TMS-pulse (0-200 ms) in the μ-frequency band was found for trough compared to peak stimulation trials in both study visits. Phase-dependent TMS delivery might be crucial not only to amplify local effects but also to increase the magnitude and reliability of the response to the external perturbation, with implications for interventions aimed at engaging more distributed functional brain networks. KEY POINTS: Synchronized transcranial magnetic stimulation (TMS) pulses with pre-defined brain oscillatory phases allow evaluation of the impact of brain states on TMS effects. TMS pulses over M1 at the negative peak of the μ-frequency band induce higher phase-lock synchronization with interconnected contralateral homologous regions. Cortico-cortical synchronization changes are linearly predicted by the fibre density and cross-section of the white matter tract that connects the two brain regions. Phase-dependent TMS delivery might be crucial not only to amplify local effects but also to increase the magnitude and reliability of within-network synchronization.
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Affiliation(s)
- Davide Momi
- Berenson-Allen Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Boston, MA, USA,Department of Neuroscience, Imaging and Clinical Sciences, University of Chieti-Pescara, Chieti
| | - Recep A. Ozdemir
- Berenson-Allen Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Ehsan Tadayon
- Berenson-Allen Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Pierre Boucher
- Berenson-Allen Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Alberto Di Domenico
- Department of Psychological Science, Humanities and Territory, University of Chieti-Pescara, Chieti, Italy
| | - Mirco Fasolo
- Department of Psychological Science, Humanities and Territory, University of Chieti-Pescara, Chieti, Italy
| | - Mouhsin M. Shafi
- Berenson-Allen Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Boston, MA, USA,Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Alvaro Pascual-Leone
- Hinda and Arthur Marcus Institute for Aging Research and Deanna and Sidney Wolk Center for Memory Health, Hebrew SeniorLife, Boston MA,Department of Neurology, Harvard Medical School, Boston, MA, USA,Guttmann Brain Health Institute, Guttmann Institut, Universitat Autonoma, Barcelona, Spain
| | - Emiliano Santarnecchi
- Berenson-Allen Center for Non-Invasive Brain Stimulation, Beth Israel Deaconess Medical Center, Boston, MA, USA,Department of Neurology, Harvard Medical School, Boston, MA, USA
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Crasta JE, Tucker RN, Robinson J, Chen HW, Crocetti D, Suskauer SJ. Altered white matter diffusivity and subtle motor function in a pilot cohort of adolescents with sports-related concussion. Brain Inj 2022; 36:393-400. [PMID: 35157539 PMCID: PMC9133076 DOI: 10.1080/02699052.2022.2034181] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Background and objective: Adolescents with sports-related concussion (SRC) demonstrate acute and persistent deficits in subtle motor function. However, there is limited research examining related neurological underpinnings. This pilot study examined changes in motor-associated white matter pathways using diffusion tensor imaging (DTI) and their relationship with subtle motor function. Methods: Twelve adolescents with SRC (12–17 years) within two-weeks post-injury and 13 never-injured neurotypical peers completed DTI scanning. A subset of 6 adolescents with SRC returned for a follow-up visit post-medical clearance from concussion. Subtle motor function was evaluated using the Physical and Neurological Examination of Subtle Signs (PANESS). Results: Adolescents with SRC showed higher mean diffusivity (MD) of the superior corona radiata and greater subtle motor deficits compared to controls. Across all participants, greater subtle motor deficits were associated with higher (more atypical) MD of the superior corona radiata. Preliminary longitudinal analysis indicated reduction in fractional anisotropy of the corpus callosum but no change in the MD of the superior corona radiata from the initial visit to the follow-up visit post-medical clearance. Conclusions: These findings support preliminary evidence for a brain–behavior relationship between superior corona radiata microstructure and subtle motor deficits in adolescents with SRC that merits further investigation.
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Affiliation(s)
- Jewel E Crasta
- Occupational Therapy Division, The Ohio State University, Columbus, Ohio, USA
| | | | | | | | | | - Stacy J Suskauer
- Kennedy Krieger Institute, Baltimore, Maryland, USA.,Department of Physical Medicine and Rehabilitation and Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Decoeur F, Picard K, St-Pierre MK, Greenhalgh AD, Delpech JC, Sere A, Layé S, Tremblay ME, Nadjar A. N-3 PUFA Deficiency Affects the Ultrastructural Organization and Density of White Matter Microglia in the Developing Brain of Male Mice. Front Cell Neurosci 2022; 16:802411. [PMID: 35221920 PMCID: PMC8866569 DOI: 10.3389/fncel.2022.802411] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 01/17/2022] [Indexed: 02/03/2023] Open
Abstract
Over the last century, westernization of dietary habits has led to a dramatic reduction in dietary intake of n-3 polyunsaturated fatty acids (n-3 PUFAs). In particular, low maternal intake of n-3 PUFAs throughout gestation and lactation causes defects in brain myelination. Microglia are recognized for their critical contribution to neurodevelopmental processes, such as myelination. These cells invade the white matter in the first weeks of the post-natal period, where they participate in oligodendrocyte maturation and myelin production. Therefore, we investigated whether an alteration of white matter microglia accompanies the myelination deficits observed in the brain of n-3 PUFA-deficient animals. Macroscopic imaging analysis shows that maternal n-3 PUFA deficiency decreases the density of white matter microglia around post-natal day 10. Microscopic electron microscopy analyses also revealed alterations of microglial ultrastructure, a decrease in the number of contacts between microglia and myelin sheet, and a decreased amount of myelin debris in their cell body. White matter microglia further displayed increased mitochondrial abundance and network area under perinatal n-3 PUFA deficiency. Overall, our data suggest that maternal n-3 PUFA deficiency alters the structure and function of microglial cells located in the white matter of pups early in life, and this could be the key to understand myelination deficits during neurodevelopment.
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Affiliation(s)
- Fanny Decoeur
- INRAE, Bordeaux INP, NutriNeuro, Université de Bordeaux, Bordeaux, France
| | - Katherine Picard
- Axe Neurosciences, Centre de Recherche du CHU de Québec–Université Laval, Québec, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Département de Médecine Moléculaire, Université Laval, Québec, QC, Canada
| | - Marie-Kim St-Pierre
- Axe Neurosciences, Centre de Recherche du CHU de Québec–Université Laval, Québec, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Département de Médecine Moléculaire, Université Laval, Québec, QC, Canada
| | | | | | - Alexandra Sere
- INRAE, Bordeaux INP, NutriNeuro, Université de Bordeaux, Bordeaux, France
| | - Sophie Layé
- INRAE, Bordeaux INP, NutriNeuro, Université de Bordeaux, Bordeaux, France
| | - Marie-Eve Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec–Université Laval, Québec, QC, Canada
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Département de Médecine Moléculaire, Université Laval, Québec, QC, Canada
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada
| | - Agnès Nadjar
- INRAE, Bordeaux INP, NutriNeuro, Université de Bordeaux, Bordeaux, France
- Neurocentre Magendie, U1215, INSERM-Université de Bordeaux, Bordeaux, France
- Institut Universitaire de France (IUF), Paris, France
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29
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Dall'Orso S, Arichi T, Fitzgibbon SP, Edwards AD, Burdet E, Muceli S. Development of functional organization within the sensorimotor network across the perinatal period. Hum Brain Mapp 2022; 43:2249-2261. [PMID: 35088920 PMCID: PMC8996360 DOI: 10.1002/hbm.25785] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 12/30/2021] [Accepted: 01/10/2022] [Indexed: 11/18/2022] Open
Abstract
In the mature human brain, the neural processing related to different body parts is reflected in patterns of functional connectivity, which is strongest between functional homologs in opposite cortical hemispheres. To understand how this organization is first established, we investigated functional connectivity between limb regions in the sensorimotor cortex in 400 preterm and term infants aged across the equivalent period to the third trimester of gestation (32–45 weeks postmenstrual age). Masks were obtained from empirically derived functional responses in neonates from an independent data set. We demonstrate the early presence of a crude but spatially organized functional connectivity, that rapidly matures across the preterm period to achieve an adult‐like configuration by the normal time of birth. Specifically, connectivity was strongest between homolog regions, followed by connectivity between adjacent regions (different limbs but same hemisphere) already in the preterm brain, and increased with age. These changes were specific to the sensorimotor network. Crucially, these trajectories were strongly dependent on age more than age of birth. This demonstrates that during the perinatal period the sensorimotor cortex undergoes preprogrammed changes determining the functional movement organization that are not altered by preterm birth in absence of brain injury.
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Affiliation(s)
- Sofia Dall'Orso
- Department of Electrical Engineering, Chalmers University of Technology, Gothenburg.,Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London
| | - Tomoki Arichi
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London.,Department of Bioengineering, Imperial College of Science, Technology and Medicine, London, UK.,Paediatric Neurosciences, Evelina London Children's Hospital, St. Thomas' Hospital, London, UK.,Medical Research Council Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Sean P Fitzgibbon
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - A David Edwards
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London.,Medical Research Council Centre for Neurodevelopmental Disorders, King's College London, London, UK
| | - Etienne Burdet
- Department of Bioengineering, Imperial College of Science, Technology and Medicine, London, UK
| | - Silvia Muceli
- Department of Electrical Engineering, Chalmers University of Technology, Gothenburg.,Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London
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30
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González-Madruga K, Staginnus M, Fairchild G. Alterations in Structural and Functional Connectivity in ADHD: Implications for Theories of ADHD. Curr Top Behav Neurosci 2022; 57:445-481. [PMID: 35583796 DOI: 10.1007/7854_2022_345] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Attention-Deficit/Hyperactivity Disorder (ADHD) is increasingly viewed as a disorder of brain connectivity. We review connectivity-based theories of ADHD including the default mode network (DMN) interference and multiple network hypotheses. We outline the main approaches used to study brain connectivity in ADHD: diffusion tensor imaging and resting-state functional connectivity. We discuss the basic principles underlying these methods and the main analytical approaches used and consider what the findings have told us about connectivity alterations in ADHD. The most replicable finding in the diffusion tensor imaging literature on ADHD is lower fractional anisotropy in the corpus callosum, a key commissural tract which connects the brain's hemispheres. Meta-analyses of resting-state functional connectivity studies have failed to identify spatial convergence across studies, with the exception of meta-analyses focused on specific networks which have reported within-network connectivity alterations in the DMN and between the DMN and the fronto-parietal control and salience networks. Overall, methodological heterogeneity between studies and differences in sample characteristics are major barriers to progress in this area. In addition, females, adults and medication-naïve/unmedicated individuals are under-represented in connectivity studies, comorbidity needs to be assessed more systematically, and longitudinal research is needed to investigate whether ADHD is characterized by maturational delays in connectivity.
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31
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Lee J, Kim H, Kim J, Chang WH, Kim YH. Multimodal Imaging Biomarker-Based Model Using Stratification Strategies for Predicting Upper Extremity Motor Recovery in Severe Stroke Patients. Neurorehabil Neural Repair 2021; 36:217-226. [PMID: 34970925 DOI: 10.1177/15459683211070278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background. Various prognostic biomarkers for upper extremity (UE) motor recovery after stroke have been reported. However, most have relatively low predictive accuracy in severe stroke patients.Objective. This study suggests an imaging biomarker-based model for effectively predicting UE recovery in severe stroke patients.Methods. Of 104 ischemic stroke patients screened, 42 with severe motor impairment were included. All patients underwent structural, diffusion, and functional magnetic resonance imaging at 2 weeks and underwent motor function assessments at 2 weeks and 3 months after stroke onset. According to motor function recovery at 3 months, patients were divided into good and poor subgroups. The value of multimodal imaging biomarkers of lesion load, lesion volume, white matter integrity, and cortical functional connectivity for motor recovery prediction was investigated in each subgroup.Results. Imaging biomarkers varied depending on recovery pattern. The integrity of the cerebellar tract (P = .005, R2 = .432) was the primary biomarker in the good recovery group. In contrast, the sensory-related corpus callosum tract (P = .026, R2 = .332) and sensory-related functional connectivity (P = .001, R2 = .531) were primary biomarkers in the poor recovery group. A prediction model was proposed by applying each biomarker in the subgroup to patients with different motor evoked potential responses (P < .001, R2 = .853, root mean square error = 5.28).Conclusions. Our results suggest an optimized imaging biomarker model for predicting UE motor recovery after stroke. This model can contribute to individualized management of severe stroke in a clinical setting.
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Affiliation(s)
- Jungsoo Lee
- Department of Physical and Rehabilitation Medicine, Center for Prevention and Rehabilitation, Heart Vascular Stroke Institute, 36626Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Heegoo Kim
- Department of Health Sciences and Technology, Department of Medical Device Management and Research, Department of Digital Health, SAIHST, 35017Sungkyunkwan University, Seoul, Republic of Korea
| | - Jinuk Kim
- Department of Health Sciences and Technology, Department of Medical Device Management and Research, Department of Digital Health, SAIHST, 35017Sungkyunkwan University, Seoul, Republic of Korea
| | - Won Hyuk Chang
- Department of Physical and Rehabilitation Medicine, Center for Prevention and Rehabilitation, Heart Vascular Stroke Institute, 36626Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Yun-Hee Kim
- Department of Physical and Rehabilitation Medicine, Center for Prevention and Rehabilitation, Heart Vascular Stroke Institute, 36626Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.,Department of Health Sciences and Technology, Department of Medical Device Management and Research, Department of Digital Health, SAIHST, 35017Sungkyunkwan University, Seoul, Republic of Korea
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32
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Belyk M, Eichert N, McGettigan C. A dual larynx motor networks hypothesis. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200392. [PMID: 34719252 PMCID: PMC8558777 DOI: 10.1098/rstb.2020.0392] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2021] [Indexed: 01/14/2023] Open
Abstract
Humans are vocal modulators par excellence. This ability is supported in part by the dual representation of the laryngeal muscles in the motor cortex. Movement, however, is not the product of motor cortex alone but of a broader motor network. This network consists of brain regions that contain somatotopic maps that parallel the organization in motor cortex. We therefore present a novel hypothesis that the dual laryngeal representation is repeated throughout the broader motor network. In support of the hypothesis, we review existing literature that demonstrates the existence of network-wide somatotopy and present initial evidence for the hypothesis' plausibility. Understanding how this uniquely human phenotype in motor cortex interacts with broader brain networks is an important step toward understanding how humans evolved the ability to speak. We further suggest that this system may provide a means to study how individual components of the nervous system evolved within the context of neuronal networks. This article is part of the theme issue 'Voice modulation: from origin and mechanism to social impact (Part I)'.
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Affiliation(s)
- Michel Belyk
- Department of Speech Hearing and Phonetic Sciences, University College London, London WC1N 1PJ, UK
- Department of Psychology, Edge Hill University, Ormskirk, L39 4QP, UK
| | - Nicole Eichert
- Wellcome Centre for Integrative Neuroimaging, Centre for Functional MRI of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK
| | - Carolyn McGettigan
- Department of Speech Hearing and Phonetic Sciences, University College London, London WC1N 1PJ, UK
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33
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Bihemispheric sensorimotor oscillatory network states determine cortical responses to transcranial magnetic stimulation. Brain Stimul 2021; 15:167-178. [PMID: 34896304 DOI: 10.1016/j.brs.2021.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 12/05/2021] [Accepted: 12/07/2021] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Brain responses to external stimuli vary with fluctuating states of neuronal activity. Previous work has demonstrated effects of phase and power of the ongoing local sensorimotor μ-alpha-oscillation on responses to transcranial magnetic stimulation (TMS) of motor cortex (M1). However, M1 is part of a distributed network, and the effects of oscillatory activity in this network on TMS-evoked EEG responses (TEPs) have not been explored. OBJECTIVES To determine the effects of oscillatory activity in the bihemispheric sensorimotor network on TEPs. METHODS 31 healthy subjects received single-pulse TMS of the left M1 hand area during EEG recording. Ongoing bihemispheric sensorimotor cortex oscillatory states were reconstructed from the EEG directly preceding TMS, and inferred by a data-driven method combining a multivariate autoregressive model and a Hidden Markov model. TEP amplitudes (P25, N45, P70, N100 and P180) were then compared between different bihemispheric sensorimotor cortex oscillatory states. RESULTS Four bihemispheric sensorimotor cortex oscillatory states were identified, with different interhemispheric expressions of theta and alpha oscillations. High alpha-power states in the stimulated sensorimotor cortex increased P25 amplitude. Alpha power in the alpha-alpha state (stimulated - non-stimulated hemisphere) correlated in both hemispheres with N45 amplitude. Theta power in the alpha-theta state correlated in the non-stimulated hemisphere with P70 amplitude. CONCLUSIONS Bihemispheric sensorimotor cortex oscillatory states contribute to TEPs, with a relevance shift from stimulated to non-stimulated M1 from P25 over N45 to P70. This significantly extends previous findings: not only ongoing local oscillations but distributed network oscillatory states determine cortical responsiveness to external stimuli.
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34
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Peters DM, Fridriksson J, Richardson JD, Stewart JC, Rorden C, Bonilha L, Middleton A, Fritz SL. Upper and Lower Limb Motor Function Correlates with Ipsilesional Corticospinal Tract and Red Nucleus Structural Integrity in Chronic Stroke: A Cross-Sectional, ROI-Based MRI Study. Behav Neurol 2021; 2021:3010555. [PMID: 34804258 PMCID: PMC8601844 DOI: 10.1155/2021/3010555] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 10/27/2021] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Structural integrity of the ipsilesional corticospinal tract (CST) is important for upper limb motor recovery after stroke. However, additional neuromechanisms associated with motor function poststroke are less well understood, especially regarding the lower limb. OBJECTIVE To investigate the neural basis of upper/lower limb motor deficits poststroke by correlating measures of motor function with diffusion tensor imaging-derived indices of white matter integrity (fractional anisotropy (FA), mean diffusivity (MD)) in primary and secondary motor tracts/structures. METHODS Forty-three individuals with chronic stroke (time poststroke, 64.4 ± 58.8 months) underwent a comprehensive motor assessment and MRI scanning. Correlation and multiple regression analyses were performed to examine relationships between FA/MD in a priori motor tracts/structures and motor function. RESULTS FA in the ipsilesional CST and red nucleus (RN) was positively correlated with motor function of both the affected upper and lower limb (r = 0.36-0.55, p ≤ 0.01), while only ipsilesional RN FA was associated with gait speed (r = 0.50). Ipsilesional CST FA explained 37.3% of the variance in grip strength (p < 0.001) and 31.5% of the variance in Arm Motricity Index (p = 0.004). Measures of MD were not predictors of motor performance. CONCLUSIONS Microstructural integrity of the ipsilesional CST is associated with both upper and lower limb motor function poststroke, but appears less important for gait speed. Integrity of the ipsilesional RN was also associated with motor performance, suggesting increased contributions from secondary motor areas may play a role in supporting chronic motor function and could become a target for interventions.
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Affiliation(s)
- Denise M. Peters
- Department of Rehabilitation and Movement Science, University of Vermont, 106 Carrigan Dr., Burlington, VT, USA
| | - Julius Fridriksson
- Department of Communication Sciences and Disorders, University of South Carolina, 915 Greene St., Columbia, SC, USA
| | - Jessica D. Richardson
- Department of Speech and Hearing Sciences, University of New Mexico, 1700 Lomas Blvd., Albuquerque, NM, USA
| | - Jill C. Stewart
- Department of Exercise Science, Physical Therapy Program, University of South Carolina, 921 Assembly St., Columbia, SC, USA
| | - Chris Rorden
- Department of Psychology, University of South Carolina, 1512 Pendleton St., Columbia, SC, USA
| | - Leonardo Bonilha
- Department of Neurology, Medical University of South Carolina, 96 Jonathan Lucas St., Charleston, SC, USA
| | - Addie Middleton
- New England Geriatric Research Education and Clinical Center, VA Boston Healthcare System, 150 South Huntington Ave., Jamaica Plain, MA, USA
| | - Stacy L. Fritz
- Department of Exercise Science, Physical Therapy Program, University of South Carolina, 921 Assembly St., Columbia, SC, USA
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35
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Vuong A, Fowler EG, Matsumoto J, Staudt LA, Yokota H, Joshi SH. Selective Motor Control is a Clinical Correlate of Brain Motor Tract Impairment in Children with Spastic Bilateral Cerebral Palsy. AJNR Am J Neuroradiol 2021; 42:2054-2061. [PMID: 34593378 PMCID: PMC8583266 DOI: 10.3174/ajnr.a7272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 06/23/2021] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Selective voluntary motor control is an important factor influencing gross motor function, interjoint coordination, and the outcome of hamstring-lengthening surgery in spastic cerebral palsy. Using DTI, we investigated whether selective voluntary motor control would show strong correlations with WM motor tract microstructure and whether selective voluntary motor control is more sensitive to global WM impairment than gross motor function. MATERIALS AND METHODS Children with spastic bilateral cerebral palsy born preterm and typically developing children were recruited. The Selective Control Assessment of the Lower Extremity (SCALE) and Gross Motor Function Measure (GMFM) were assessed in participants with cerebral palsy. Participants underwent brain MR imaging to collect DWI data. Tract-Based Spatial Statistics was used to analyze the WM for between-group differences and correlations with SCALE and GMFM. ROI analyses compared motor regions. RESULTS Twelve children with cerebral palsy (mean age, 11.5 years) and 12 typically developing children (mean age, 10.3 years) participated. Altered DTI outcomes were found throughout the whole brain for the cerebral palsy group. SCALE, developed to evaluate selective voluntary motor control in cerebral palsy, showed significant positive correlations with fractional anisotropy in more WM voxels throughout the whole brain and for motor regions, including the corticospinal tract and corpus callosum, compared with GMFM. A significant negative correlation between radial diffusivity and SCALE, but not GMFM, was found within the corpus callosum. CONCLUSIONS SCALE was a more sensitive clinical correlate of motor and whole-brain WM tract impairment in children with spastic bilateral cerebral palsy, suggesting greater anisotropy and myelination in these regions for those with higher selective voluntary motor control.
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Affiliation(s)
- A Vuong
- From the Departments of Bioengineering (A.V., S.H.J.)
- Orthopaedic Surgery (A.V., E.G.F., L.A.S.)
- Center for Cerebral Palsy at UCLA/Orthopaedic Institute for Children (A.V., E.G.F., L.A.S.), Los Angeles, California
| | - E G Fowler
- Orthopaedic Surgery (A.V., E.G.F., L.A.S.)
- Center for Cerebral Palsy at UCLA/Orthopaedic Institute for Children (A.V., E.G.F., L.A.S.), Los Angeles, California
| | | | - L A Staudt
- Orthopaedic Surgery (A.V., E.G.F., L.A.S.)
- Center for Cerebral Palsy at UCLA/Orthopaedic Institute for Children (A.V., E.G.F., L.A.S.), Los Angeles, California
| | - H Yokota
- Department of Diagnostic Radiology and Radiation (H.Y.), Chiba University Hospital, Chiba, Japan
| | - S H Joshi
- From the Departments of Bioengineering (A.V., S.H.J.)
- Ahmanson-Lovelace Brain Mapping Center in the Department of Neurology (S.H.J.), University of California Los Angeles, Los Angeles, California
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Verstraelen S, Cuypers K, Maes C, Hehl M, Van Malderen S, Levin O, Mikkelsen M, Meesen RLJ, Swinnen SP. Neurophysiological modulations in the (pre)motor-motor network underlying age-related increases in reaction time and the role of GABA levels - a bimodal TMS-MRS study. Neuroimage 2021; 243:118500. [PMID: 34428570 PMCID: PMC8547554 DOI: 10.1016/j.neuroimage.2021.118500] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 08/17/2021] [Accepted: 08/20/2021] [Indexed: 01/10/2023] Open
Abstract
It has been argued that age-related changes in the neurochemical and neurophysiological properties of the GABAergic system may underlie increases in reaction time (RT) in older adults. However, the role of GABA levels within the sensorimotor cortices (SMC) in mediating interhemispheric interactions (IHi) during the processing stage of a fast motor response, as well as how both properties explain interindividual differences in RT, are not yet fully understood. In this study, edited magnetic resonance spectroscopy (MRS) was combined with dual-site transcranial magnetic stimulation (dsTMS) for probing GABA+ levels in bilateral SMC and task-related neurophysiological modulations in corticospinal excitability (CSE), and primary motor cortex (M1)-M1 and dorsal premotor cortex (PMd)-M1 IHi, respectively. Both CSE and IHi were assessed during the preparatory and premotor period of a delayed choice RT task. Data were collected from 25 young (aged 18-33 years) and 28 older (aged 60-74 years) healthy adults. Our results demonstrated that older as compared to younger adults exhibited a reduced bilateral CSE suppression, as well as a reduced magnitude of long latency M1-M1 and PMd-M1 disinhibition during the preparatory period, irrespective of the direction of the IHi. Importantly, in older adults, the GABA+ levels in bilateral SMC partially accounted for task-related neurophysiological modulations as well as individual differences in RT. In contrast, in young adults, neither task-related neurophysiological modulations, nor individual differences in RT were associated with SMC GABA+ levels. In conclusion, this study contributes to a comprehensive initial understanding of how age-related differences in neurochemical properties and neurophysiological processes are related to increases in RT.
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Affiliation(s)
- Stefanie Verstraelen
- Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, 3590 Diepenbeek, Belgium
| | - Koen Cuypers
- Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, 3590 Diepenbeek, Belgium; Movement Control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, 3001 Heverlee, Belgium.
| | - Celine Maes
- Movement Control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, 3001 Heverlee, Belgium; KU Leuven Brain Institute (LBI), Leuven, Belgium
| | - Melina Hehl
- Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, 3590 Diepenbeek, Belgium; Movement Control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, 3001 Heverlee, Belgium
| | - Shanti Van Malderen
- Movement Control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, 3001 Heverlee, Belgium
| | - Oron Levin
- Movement Control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, 3001 Heverlee, Belgium
| | - Mark Mikkelsen
- Russel H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Raf L J Meesen
- Neuroplasticity and Movement Control Research Group, Rehabilitation Research Institute (REVAL), Hasselt University, 3590 Diepenbeek, Belgium; Movement Control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, 3001 Heverlee, Belgium
| | - Stephan P Swinnen
- Movement Control & Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, 3001 Heverlee, Belgium; KU Leuven Brain Institute (LBI), Leuven, Belgium
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37
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Terece C, Gürpınar K, Büyükatak K, Atacan SÇ, Ağırbaş A, Madazlı R. Evaluation of medical malpractice claims in obstetric ultrasonography: Opinion of The Council of Forensic Medicine in Turkey. J Forensic Leg Med 2021; 84:102257. [PMID: 34688159 DOI: 10.1016/j.jflm.2021.102257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 09/23/2021] [Accepted: 09/27/2021] [Indexed: 11/30/2022]
Abstract
AIM The Council of Forensic Medicine is an institution affiliated with the Ministry of Justice in the Republic of Turkey which acts in an official oversight capacity in cases of alleged medical malpractice in forensic medical science. Sonographers may face judicial sanctions as a result of ultrasonography examinations that they do not perform according to current guidelines. In this study we focused our attention to claims of medical malpractice related to obstetric ultrasonography that had been referred to the Council of Forensic Medicine. Our aim was to investigate the causes of malpractice claims related to obstetric ultrasonography and to present the expert opinions of our council about these claims in the light of literature. We have also planned to discuss what can be done with current guideline information to prevent situations that cause malpractice claims. MATERIALS AND METHODS The study herein was performed on 73 claims of medical malpractice in obstetric ultrasonography findings, all of which were referred by forensic authorities to the Second Specialization Board of Council Forensic Medicine from 2014 to 2018. A retrospective review of the reports generated from information contained within case files illuminates the reasoning behind medical error claims. Among the reasons examined are features of the ultrasonographic evaluation (number, week of examination, health institution), the traits of the evaluating physicians (institutions, branches, academic titles), congenital anomalies detected after birth, and maternal age. RESULTS Analysis of the data shows that 79.5% of ultrasonographic examinations leading to claims of medical malpractice were performed in private health institutions. All cases of medical malpractice claims were associated with undiagnosed congenital anomalies, and that the form for informed consent was obtained for only 19.1% of cases that underwent second level ultrasonographic examination. Further, 53.3% of cases with congenital anomalies subject to litigation were anomalies of the extremities, and all four cases of alleged malpractice within obstetric ultrasonography were associated with extremity anomalies. The variety of academic titles of physicians performing the ultrasonographic examinations was not statistically significant. It was concluded that two ultrasonography examinations performed by two nuclear medicine specialists were not in accordance with medical norms. CONCLUSION Although organizations such as AIUM, ACR, and ACOG try to set standards for ultrasound examination through practice guidelines, it is difficult to establish optimal standards for ultrasonographic examination. In light of the guidelines created by the above organizations, each country should set its own standard based on their own socioeconomic and health data. We conclude that it is not appropriate for obstetric ultrasonographic examinations to be performed by specialists in fields such as nuclear medicine, where ultrasonographic examinations are not a part of the core training curriculum. Obtaining a signed informed consent form from the patient prior to the second level ultrasonography examination will be useful for medicolegal defense purposes should a subsequent claim of malpractice be filed.
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Affiliation(s)
- Cem Terece
- Council of Forensic Medicine, Forensic Medicine, İstanbul, Turkey.
| | - Kağan Gürpınar
- Council of Forensic Medicine, Forensic Medicine, İstanbul, Turkey.
| | - Koray Büyükatak
- Council of Forensic Medicine, Forensic Medicine, İstanbul, Turkey.
| | - Sibel Çağlar Atacan
- Council of Forensic Medicine, Second Specialization Board of Council of Forensic Medicine, İstanbul, Turkey.
| | - Ajda Ağırbaş
- Council of Forensic Medicine, Second Specialization Board of Council of Forensic Medicine, İstanbul, Turkey.
| | - Rıza Madazlı
- İstanbul University Cerrahpasa Medical Faculty, Department of Obstetrics and Gynecology, İstanbul, Turkey.
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Paradoxical facilitation alongside interhemispheric inhibition. Exp Brain Res 2021; 239:3303-3313. [PMID: 34476535 PMCID: PMC8541949 DOI: 10.1007/s00221-021-06183-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 07/20/2021] [Indexed: 11/03/2022]
Abstract
Neurophysiological experiments using transcranial magnetic stimulation (TMS) have sought to probe the function of the motor division of the corpus callosum. Primary motor cortex sends projections via the corpus callosum with a net inhibitory influence on the homologous region of the opposite hemisphere. Interhemispheric inhibition (IHI) experiments probe this inhibitory pathway. A test stimulus (TS) delivered to the motor cortex in one hemisphere elicits motor evoked potentials (MEPs) in a target muscle, while a conditioning stimulus (CS) applied to the homologous region of the opposite hemisphere modulates the effect of the TS. We predicted that large CS MEPs would be associated with increased IHI since they should be a reliable index of how effectively contralateral motor cortex was stimulated and therefore of the magnitude of interhemispheric inhibition. However, we observed a strong tendency for larger CS MEPs to be associated with reduced interhemispheric inhibition which in the extreme lead to a net effect of facilitation. This surprising effect was large, systematic, and observed in nearly all participants. We outline several hypotheses for mechanisms which may underlie this phenomenon to guide future research.
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Interhemispheric Cortico-Cortical Pathway for Sequential Bimanual Movements in Mice. eNeuro 2021; 8:ENEURO.0200-21.2021. [PMID: 34348983 PMCID: PMC8387156 DOI: 10.1523/eneuro.0200-21.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 07/23/2021] [Accepted: 07/28/2021] [Indexed: 12/03/2022] Open
Abstract
Animals precisely coordinate their left and right limbs for various adaptive purposes. While the left and right limbs are clearly controlled by different cortical hemispheres, the neural mechanisms that determine the action sequence between them remains elusive. Here, we have established a novel head-fixed bimanual-press (biPress) sequence task in which mice sequentially press left and right pedals with their forelimbs in a predetermined order. Using this motor task, we found that the motor cortical neurons responsible for the first press (1P) also generate independent motor signals for the second press (2P) by the opposite forelimb during the movement transitions between forelimbs. Projection-specific calcium imaging and optogenetic manipulation revealed these motor signals are transferred from one motor cortical hemisphere to the other via corticocortical projections. Together, our results suggest the motor cortices coordinate sequential bimanual movements through corticocortical pathways.
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Gooijers J, De Luca A, Zivari Adab H, Leemans A, Roebroeck A, Swinnen SP. Indices of callosal axonal density and radius from diffusion MRI relate to upper and lower limb motor performance. Neuroimage 2021; 241:118433. [PMID: 34324975 DOI: 10.1016/j.neuroimage.2021.118433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 07/15/2021] [Accepted: 07/26/2021] [Indexed: 11/16/2022] Open
Abstract
Understanding the relationship between human brain structure and functional outcome is of critical importance in systems neuroscience. Diffusion MRI (dMRI) studies show that fractional anisotropy (FA) is predictive of motor control, underscoring the importance of white matter (WM). However, as FA is a surrogate marker of WM, we aim to shed new light on the structural underpinnings of this relationship by applying a multi-compartment microstructure model providing axonal density/radius indices. Sixteen young adults (7 males / 9 females), performed a hand/foot tapping task and a Multi Limb Reaction Time task. Furthermore, diffusion (STEAM &HARDI) and fMRI (localizer hand/foot activations) data were obtained. Sphere ROIs were placed on activation clusters with highest t value to guide interhemispheric WM tractography. Axonal radius/density indices of callosal parts intersecting with tractography were calculated from STEAM, using the diffusion-time dependent AxCaliber model, and correlated with behavior. Results indicated a possible association between larger apparent axonal radii of callosal motor fibers of the hand and higher tapping scores of both hands, and faster selection-related processing (normalized reaction) times (RTs) on diagonal limb combinations. Additionally, a trend was present for faster selection-related processing (normalized reaction) times for lower limbs being related with higher axonal density of callosal foot motor fibers, and for higher FA values of callosal motor fibers in general being related with better tapping and faster selection-related processing (normalized reaction) times. Whereas FA is sensitive in demonstrating associations with motor behavior, axon radius/density (i.e., fiber geometry) measures are promising to explain the physiological source behind the observed FA changes, contributing to deeper insights into brain-behavior interactions.
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Affiliation(s)
- J Gooijers
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Leuven (3000), Belgium; LBI-KU Leuven Brain Institute, Leuven (3000), Belgium.
| | - A De Luca
- PROVIDI Lab, Image Sciences Institute, University Medical Center Utrecht, Utrecht 3584 CX, Netherlands; Neurology Department, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht 3584 CX, Netherlands
| | - H Zivari Adab
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Leuven (3000), Belgium; LBI-KU Leuven Brain Institute, Leuven (3000), Belgium
| | - A Leemans
- PROVIDI Lab, Image Sciences Institute, University Medical Center Utrecht, Utrecht 3584 CX, Netherlands
| | - A Roebroeck
- Department of Cognitive Neuroscience, Faculty of Psychology & Neuroscience, Maastricht University, Maastricht 6229 EV, Netherlands
| | - S P Swinnen
- Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, KU Leuven, Leuven (3000), Belgium; LBI-KU Leuven Brain Institute, Leuven (3000), Belgium
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Guder S, Frey BM, Backhaus W, Braass H, Timmermann JE, Gerloff C, Schulz R. The Influence of Cortico-Cerebellar Structural Connectivity on Cortical Excitability in Chronic Stroke. Cereb Cortex 2021; 30:1330-1344. [PMID: 31647536 DOI: 10.1093/cercor/bhz169] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/17/2019] [Accepted: 06/22/2019] [Indexed: 12/11/2022] Open
Abstract
Brain imaging has recently evidenced that the structural state of distinct reciprocal cortico-cerebellar fiber tracts, the dentato-thalamo-cortical tract (DTCT), and the cortico-ponto-cerebellar tract (CPCeT), significantly influences residual motor output in chronic stroke patients, independent from the level of damage to the corticospinal tract (CST). Whether such structural information might also directly relate to measures of cortical excitability is an open question. Eighteen chronic stroke patients with supratentorial ischemic lesions and 17 healthy controls underwent transcranial magnetic stimulation to assess recruitment curves of motor evoked potentials of both hemispheres. Diffusion-weighted imaging and probabilistic tractography were applied to reconstruct reciprocal cortico-cerebellar motor tracts between the primary motor cortex and the cerebellum. Tract-related microstructure was estimated by means of fractional anisotropy, and linear regression modeling was used to relate it to cortical excitability. The main finding was a significant association between cortical excitability and the structural integrity of the DTCT, the main cerebellar outflow tract, independent from the level of damage to the CST. A comparable relationship was neither detectable for the CPCeT nor for the healthy controls. This finding contributes to a mechanistic understanding of the putative supportive role of the cerebellum for residual motor output by facilitating cortical excitability after stroke.
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Affiliation(s)
- Stephanie Guder
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Benedikt M Frey
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Winifried Backhaus
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Hanna Braass
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Jan E Timmermann
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Christian Gerloff
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Robert Schulz
- Department of Neurology, University Medical Centre Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
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Interference of commissural connections through the genu of the corpus callosum specifically impairs sensorimotor gating. Behav Brain Res 2021; 411:113383. [PMID: 34048871 DOI: 10.1016/j.bbr.2021.113383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 05/19/2021] [Accepted: 05/22/2021] [Indexed: 11/20/2022]
Abstract
White matter abnormalities in schizophrenic patients are characterized as regional tract-specific. Myelin loss at the genu of the corpus callosum (GCC) is one of the most consistent findings in schizophrenic patients across the different populations. We characterized the axons that pass through the GCC by stereotactically injecting an anterograde axonal tracing viral vector into the forceps minor of the corpus callosum in one hemisphere, and identified the homotopic brain structures that have commissural connections in the two hemispheres of the prefrontal cortex, including the anterior cingulate area, the prelimbic area, the secondary motor area, and the dorsal part of the agranular insular area, along with commissural connections with the primary motor area, caudoputamen, and claustrum. To investigate whether dysmyelination in these commissural connections is critical for the development of schizophrenia symptoms, we generated a mouse model with focal demyelination at the GCC by stereotactically injecting demyelinating agent lysolecithin into this site, and tested these mice in a battery of behavioral tasks that are used to model the schizophrenia-like symptom domains. We found that demyelination at the GCC influenced neither the social interest or mood state, nor the locomotive activity or motor coordination. Nevertheless, it specifically reduced the prepulse inhibition of acoustic startle that is a well-known measure of sensorimotor gating. This study advances our understanding of the pathophysiological contributions of the GCC-specific white matter lesion to the related disease, and demonstrates an indispensable role of interhemispheric communication between the frontal cortices for the top-down regulation of the sensorimotor gating.
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Tao B, Xiao Y, Yang B, Zeng J, Zhang W, Hu N, Yang C, Lencer R, Gong Q, Sweeney JA, Lui S. Morphological alterations of the corpus callosum in antipsychotic-naive first-episode schizophrenia before and 1-year after treatment. Schizophr Res 2021; 231:115-121. [PMID: 33839369 DOI: 10.1016/j.schres.2021.03.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 03/28/2021] [Accepted: 03/28/2021] [Indexed: 02/05/2023]
Abstract
OBJECTIVE The corpus callosum (CC) is known to be altered in patients with schizophrenia. However, its morphologic characteristics are less well studied in treatment-naive first-episode schizophrenia patients, as is the effect of antipsychotic treatment on this structure. METHODS T-1 weighted MRI scans were obtained from 160 antipsychotic-naïve first-episode schizophrenia patients (AN-FES) and 155 healthy controls (HCs) before treatment initiation. Among the patients, forty-four were available for follow-up studies after one year of antipsychotic treatment, and were divided into good-outcome (n = 31) and poor-outcome subgroups (n = 13) based on whether there was a 50% reduction in Positive and Negative Symptom Scale (PANSS) total scores from baseline. A computer algorithm was applied to automatically identify the mid-sagittal plane (MSP) and obtain morphological measurement parameters of the CC. RESULTS Compared with HCs, AN-FES patients showed a significant reduction of thickness in the posterior midbody of the CC. This deficit was correlated with severity of negative symptoms. After one year of antipsychotic treatment, there was no significant change in CC morphological measurements in schizophrenia patients, nor was there a significant difference of CC morphological measurements between good-outcome and poor-outcome subgroups at baseline or at 1-year follow-up. CONCLUSION Thickness of the posterior midbody of the CC is reduced in the early course of schizophrenia before treatment. This alteration was not affected by antipsychotic treatment and was unrelated to treatment outcome at 1-year.
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Affiliation(s)
- Bo Tao
- Huaxi MR Research Center (HMRRC), Functional and Molecular Imaging Key Laboratory of Sichuan Province, Department of Radiology, West China Hospital, Sichuan University, Chengdu, China
| | - Yuan Xiao
- Huaxi MR Research Center (HMRRC), Functional and Molecular Imaging Key Laboratory of Sichuan Province, Department of Radiology, West China Hospital, Sichuan University, Chengdu, China
| | - Beisheng Yang
- Huaxi MR Research Center (HMRRC), Functional and Molecular Imaging Key Laboratory of Sichuan Province, Department of Radiology, West China Hospital, Sichuan University, Chengdu, China
| | - Jiaxin Zeng
- Huaxi MR Research Center (HMRRC), Functional and Molecular Imaging Key Laboratory of Sichuan Province, Department of Radiology, West China Hospital, Sichuan University, Chengdu, China
| | - Wenjing Zhang
- Huaxi MR Research Center (HMRRC), Functional and Molecular Imaging Key Laboratory of Sichuan Province, Department of Radiology, West China Hospital, Sichuan University, Chengdu, China
| | - Na Hu
- Huaxi MR Research Center (HMRRC), Functional and Molecular Imaging Key Laboratory of Sichuan Province, Department of Radiology, West China Hospital, Sichuan University, Chengdu, China
| | - Chengmin Yang
- Huaxi MR Research Center (HMRRC), Functional and Molecular Imaging Key Laboratory of Sichuan Province, Department of Radiology, West China Hospital, Sichuan University, Chengdu, China
| | - Rebekka Lencer
- Department of Psychiatry and Psychotherapy, University of Lübeck, Lübeck, Germany
| | - Qiyong Gong
- Huaxi MR Research Center (HMRRC), Functional and Molecular Imaging Key Laboratory of Sichuan Province, Department of Radiology, West China Hospital, Sichuan University, Chengdu, China
| | - John A Sweeney
- Huaxi MR Research Center (HMRRC), Functional and Molecular Imaging Key Laboratory of Sichuan Province, Department of Radiology, West China Hospital, Sichuan University, Chengdu, China; Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, OH, United States
| | - Su Lui
- Huaxi MR Research Center (HMRRC), Functional and Molecular Imaging Key Laboratory of Sichuan Province, Department of Radiology, West China Hospital, Sichuan University, Chengdu, China.
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Altered interhemispheric signal propagation in schizophrenia and depression. Clin Neurophysiol 2021; 132:1604-1611. [PMID: 34030057 DOI: 10.1016/j.clinph.2021.03.039] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 02/04/2021] [Accepted: 03/19/2021] [Indexed: 01/03/2023]
Abstract
OBJECTIVE Altered interhemispheric connectivity is implicated in the pathophysiology of schizophrenia (SCZ) and major depressive disorder (MDD) and may account for deficits in lateralized cognitive processes. We measured transcranial magnetic stimulation evoked interhemispheric signal propagation (ISP), a non-invasive measure of transcallosal connectivity, and hypothesized that the SCZ and MDD groups will have increased ISP compared to healthy controls. METHODS We evaluated ISP over the dorsolateral prefrontal cortex in 34 patients with SCZ and 34 patients with MDD compared to 32 age and sex-matched healthy controls. RESULTS ISP was significantly increased in patients with SCZ and patients with MDD compared to healthy controls but did not differ between patient groups. There were no effects of antidepressant, antipsychotic, and benzodiazepine medications on ISP and our results remained unchanged after re-analysis with a region of interest method. CONCLUSION Altered ISP was found in both SCZ and MDD patient groups. This indicates that disruptions of interhemispheric signaling processes can be indexed with ISP across psychiatric populations. SIGNIFICANCE These findings enhance our knowledge of the physiological mechanisms of interhemispheric imbalances in SCZ and MDD, which may serve as potential treatment targets in future patients.
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Jin C, Qi S, Teng Y, Li C, Yao Y, Ruan X, Wei X. Integrating Structural and Functional Interhemispheric Brain Connectivity of Gait Freezing in Parkinson's Disease. Front Neurol 2021; 12:609866. [PMID: 33935931 PMCID: PMC8081966 DOI: 10.3389/fneur.2021.609866] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 03/04/2021] [Indexed: 11/23/2022] Open
Abstract
Freezing of gait (FOG) has devastating consequences for patients with Parkinson's disease (PD), but the underlying pathophysiological mechanism is unclear. This was investigated in the present study by integrated structural and functional connectivity analyses of PD patients with or without FOG (PD FOG+ and PD FOG-, respectively) and healthy control (HC) subjects. We performed resting-state functional magnetic resonance imaging (fMRI) and diffusion tensor imaging of 24 PD FOG+ patients, 37 PD FOG- patients, and 24 HCs. Tract-based spatial statistics was applied to identify white matter (WM) abnormalities across the whole brain. Fractional anisotropy (FA) and mean diffusivity (MD) of abnormal WM areas were compared among groups, and correlations between these parameters and clinical severity as determined by FOG Questionnaire (FOGQ) score were analyzed. Voxel-mirrored homotopic connectivity (VMHC) was calculated to identify brain regions with abnormal interhemispheric connectivity. Structural and functional measures were integrated by calculating correlations between VMHC and FOGQ score and between FA, MD, and VMHC. The results showed that PD FOG+ and PD FOG- patients had decreased FA in the corpus callosum (CC), cingulum (hippocampus), and superior longitudinal fasciculus and increased MD in the CC, internal capsule, corona radiata, superior longitudinal fasciculus, and thalamus. PD FOG+ patients had more WM abnormalities than PD FOG- patients. FA and MD differed significantly among the splenium, body, and genu of the CC in all three groups (P < 0.05). The decreased FA in the CC was positively correlated with FOGQ score. PD FOG+ patients showed decreased VMHC in the post-central gyrus (PCG), pre-central gyrus, and parietal inferior margin. In PD FOG+ patients, VMHC in the PCG was negatively correlated with FOGQ score but positively correlated with FA in CC. Thus, FOG is associated with impaired interhemispheric brain connectivity measured by FA, MD, and VMHC, which are related to clinical FOG severity. These results demonstrate that integrating structural and functional MRI data can provide new insight into the pathophysiological mechanism of FOG in PD.
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Affiliation(s)
- Chaoyang Jin
- College of Medicine and Biological Information Engineering, Northeastern University, Shenyang, China
| | - Shouliang Qi
- College of Medicine and Biological Information Engineering, Northeastern University, Shenyang, China
- Key Laboratory of Intelligent Computing in Medical Image, Ministry of Education, Northeastern University, Shenyang, China
| | - Yueyang Teng
- College of Medicine and Biological Information Engineering, Northeastern University, Shenyang, China
| | - Chen Li
- College of Medicine and Biological Information Engineering, Northeastern University, Shenyang, China
| | - Yudong Yao
- Department of Electrical and Computer Engineering, Stevens Institute of Technology, Hoboken, NJ, United States
| | - Xiuhang Ruan
- Department of Radiology, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, China
| | - Xinhua Wei
- Department of Radiology, Guangzhou First People's Hospital, School of Medicine, South China University of Technology, Guangzhou, China
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Corpus Callosum Remodeling in Glioma: Constancy of Fiber Density and Anisotropy in MRI. Can J Neurol Sci 2021; 49:282-286. [PMID: 33845935 DOI: 10.1017/cjn.2021.64] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Corpus callosum (CC) is the primary fiber system bridging the cerebral hemispheres and is of critical importance for glioma migration which downgrades the prognosis. Here we present the specific pattern of CC restructuring in glioma patients. We probe that the magnetic resonance imaging-based fiber count decrease can be a ready noninvasive indicator of glioma aggressivity and prognosis. We find that to maintain the callosal neural transmission efficiency, the optimum architectural density of white matter fibers remains unchanged, even though there is gross fiber loss. This adaptation occurs by CC's isotonic restructuration, a protective compensatory behavior for maintaining CC's optimal functional efficiency despite malignant infiltration.
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Guerra A, Rocchi L, Grego A, Berardi F, Luisi C, Ferreri F. Contribution of TMS and TMS-EEG to the Understanding of Mechanisms Underlying Physiological Brain Aging. Brain Sci 2021; 11:405. [PMID: 33810206 PMCID: PMC8004753 DOI: 10.3390/brainsci11030405] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/19/2021] [Accepted: 03/19/2021] [Indexed: 12/21/2022] Open
Abstract
In the human brain, aging is characterized by progressive neuronal loss, leading to disruption of synapses and to a degree of failure in neurotransmission. However, there is increasing evidence to support the notion that the aged brain has a remarkable ability to reorganize itself, with the aim of preserving its physiological activity. It is important to develop objective markers able to characterize the biological processes underlying brain aging in the intact human, and to distinguish them from brain degeneration associated with many neurological diseases. Transcranial magnetic stimulation (TMS), coupled with electromyography or electroencephalography (EEG), is particularly suited to this aim, due to the functional nature of the information provided, and thanks to the ease with which it can be integrated with behavioral manipulation. In this review, we aimed to provide up to date information about the role of TMS and TMS-EEG in the investigation of brain aging. In particular, we focused on data about cortical excitability, connectivity and plasticity, obtained by using readouts such as motor evoked potentials and transcranial evoked potentials. Overall, findings in the literature support an important potential contribution of TMS to the understanding of the mechanisms underlying normal brain aging. Further studies are needed to expand the current body of information and to assess the applicability of TMS findings in the clinical setting.
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Affiliation(s)
| | - Lorenzo Rocchi
- Department of Clinical and Movements Neurosciences, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK;
- Department of Medical Sciences and Public Health, University of Cagliari, 09124 Cagliari, Italy
| | - Alberto Grego
- Department of Neuroscience, University of Padua, 35122 Padua, Italy; (A.G.); (F.B.); (C.L.)
| | - Francesca Berardi
- Department of Neuroscience, University of Padua, 35122 Padua, Italy; (A.G.); (F.B.); (C.L.)
| | - Concetta Luisi
- Department of Neuroscience, University of Padua, 35122 Padua, Italy; (A.G.); (F.B.); (C.L.)
| | - Florinda Ferreri
- Department of Neuroscience, University of Padua, 35122 Padua, Italy; (A.G.); (F.B.); (C.L.)
- Department of Clinical Neurophysiology, Kuopio University Hospital, University of Eastern Finland, 70210 Kuopio, Finland
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Transcranial static magnetic stimulation over the motor cortex can facilitate the contralateral cortical excitability in human. Sci Rep 2021; 11:5370. [PMID: 33686102 PMCID: PMC7940605 DOI: 10.1038/s41598-021-84823-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 02/19/2021] [Indexed: 01/27/2023] Open
Abstract
Transcranial static magnetic stimulation (tSMS) has been focused as a new non-invasive brain stimulation, which can suppress the human cortical excitability just below the magnet. However, the non-regional effects of tSMS via brain network have been rarely studied so far. We investigated whether tSMS over the left primary motor cortex (M1) can facilitate the right M1 in healthy subjects, based on the hypothesis that the functional suppression of M1 can cause the paradoxical functional facilitation of the contralateral M1 via the reduction of interhemispheric inhibition (IHI) between the bilateral M1. This study was double-blind crossover trial. We measured the corticospinal excitability in both M1 and IHI from the left to right M1 by recording motor evoked potentials from first dorsal interosseous muscles using single-pulse and paired-pulse transcranial magnetic stimulation before and after the tSMS intervention for 30 min. We found that the corticospinal excitability of the left M1 decreased, while that of the right M1 increased after tSMS. Moreover, the evaluation of IHI revealed the reduced inhibition from the left to the right M1. Our findings provide new insights on the mechanistic understanding of neuromodulatory effects of tSMS in human.
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Ermolova M, Metsomaa J, Zrenner C, Kozák G, Marzetti L, Ziemann U. Spontaneous phase-coupling within cortico-cortical networks: How time counts for brain-state-dependent stimulation. Brain Stimul 2021; 14:404-406. [PMID: 33610790 PMCID: PMC7610578 DOI: 10.1016/j.brs.2021.02.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/12/2021] [Accepted: 02/15/2021] [Indexed: 11/26/2022] Open
Affiliation(s)
- Maria Ermolova
- Department of Neurology & Stroke, University of Tübingen, Germany; Hertie-Institute for Clinical Brain Research, University of Tübingen, Germany
| | - Johanna Metsomaa
- Department of Neurology & Stroke, University of Tübingen, Germany; Hertie-Institute for Clinical Brain Research, University of Tübingen, Germany
| | - Christoph Zrenner
- Department of Neurology & Stroke, University of Tübingen, Germany; Hertie-Institute for Clinical Brain Research, University of Tübingen, Germany
| | - Gábor Kozák
- Department of Neurology & Stroke, University of Tübingen, Germany; Hertie-Institute for Clinical Brain Research, University of Tübingen, Germany
| | - Laura Marzetti
- Department of Neuroscience, Imaging and Clinical Sciences, Gabriele d'Annunzio University of Chieti and Pescara, Chieti, Italy
| | - Ulf Ziemann
- Department of Neurology & Stroke, University of Tübingen, Germany; Hertie-Institute for Clinical Brain Research, University of Tübingen, Germany.
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De Marco M, Mazzoni G, Manca R, Venneri A. Functional Neural Architecture Supporting Highly Superior Autobiographical Memory. Brain Connect 2021; 11:297-307. [PMID: 33403914 DOI: 10.1089/brain.2020.0858] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Background: The neural mechanisms of highly superior autobiographical memory (HSAM) are poorly understood. To shed light on the functional magnetic resonance imaging (fMRI)-informed neurobiology of this condition, in this study we characterize for the first time the neurofunctional architecture of a 20-year-old individual (B.B.) with HSAM and no concurrent neurological/psychiatric or other clinical conditions. Materials and Methods: Relying on t-test inferential models comparing a single observation with a control group, we processed B.B.'s resting-state fMRI signal and compared it with the neurofunctional architecture of 16 young adults with normal autobiographical memory. Specifically, we analyzed large-scale brain networks, region-to-region functional connectivity, and connectivity indices informed by graph theory. Results: B.B. showed higher expression of large-scale and region-to-region connectivity, larger segregation of the pallidum and enhanced centrality of the temporal pole, orbitofrontal cortex and cerebellar lobule IX. Conclusion: These findings indicate that HSAM is associated with increased expression of neural pathways that support memory encoding, retrieval, and elaboration, but also with reduced expression of patterns typically involved in information control and metacognition, the use of which would be minimized thanks to automatic and accurate memory processing.
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Affiliation(s)
- Matteo De Marco
- Department of Neuroscience, University of Sheffield, Sheffield, United Kingdom
| | - Giuliana Mazzoni
- Department of Dynamic and Clinical Psychology, University La Sapienza, Rome, Italy
| | - Riccardo Manca
- Department of Neuroscience, University of Sheffield, Sheffield, United Kingdom
| | - Annalena Venneri
- Department of Neuroscience, University of Sheffield, Sheffield, United Kingdom
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