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Prasad S, Pandey U, Saini J, Ingalhalikar M, Pal PK. Atrophy of cerebellar peduncles in essential tremor: a machine learning-based volumetric analysis. Eur Radiol 2019; 29:7037-7046. [PMID: 31161314 DOI: 10.1007/s00330-019-06269-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 04/16/2019] [Accepted: 05/07/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND Subtle cerebellar signs are frequently observed in essential tremor (ET) and may be associated with cerebellar dysfunction. This study aims to evaluate the macrostructural integrity of the superior, middle, and inferior cerebellar peduncles (SCP, MCP, ICP) and cerebellar gray and white matter (GM, WM) volumes in patients with ET, and compare these volumes between patients with and without cerebellar signs (ETc and ETnc). METHODS Forty patients with ET and 37 age- and gender-matched healthy controls were recruited. Atlas-based region-of-interest analysis of the SCP, MCP, and ICP and automated analysis of cerebellar GM and WM volumes were performed. Peduncular volumes were employed in a multi-variate classification framework to attempt discrimination of ET from controls. RESULTS Significant atrophy of bilateral MCP and ICP and bilateral cerebellar GM was observed in ET. Cerebellar signs were present in 20% of subjects with ET. Comparison of peduncular and cerebellar volumes between ETnc and ETc revealed atrophy of right SCP, bilateral MCP and ICP, and left cerebellar WM in ETc. The multi-variate classifier could discriminate between ET and controls with a test accuracy of 86.66%. CONCLUSIONS Patients with ET have significant atrophy of cerebellar peduncles, particularly the MCP and ICP. Additional atrophy of the SCP is observed in the ETc group. These abnormalities may contribute to the pathogenesis of cerebellar signs in ET. KEY POINTS • Patients with ET have significant atrophy of bilateral middle and inferior cerebellar peduncles and cerebellar gray matter in comparison with healthy controls. • Patients of ET with cerebellar signs have significant atrophy of right superior cerebellar peduncle, bilateral middle and inferior cerebellar peduncle, and left cerebellar white matter in comparison with ET without cerebellar signs. • A multi-variate classifier employing peduncular volumes could discriminate between ET and controls with a test accuracy of 86.66%.
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Affiliation(s)
- Shweta Prasad
- Department of Clinical Neurosciences and Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, Karnataka, 560029, India
| | - Umang Pandey
- Symbiosis Center for Medical Image Analysis, Symbiosis International (Deemed) University, Lavale, Mulshi, Pune, Maharashtra, 412115, India
| | - Jitender Saini
- Department of Neuroimaging and Interventional Radiology, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, Karnataka, 560029, India
| | - Madhura Ingalhalikar
- Symbiosis Center for Medical Image Analysis, Symbiosis International (Deemed) University, Lavale, Mulshi, Pune, Maharashtra, 412115, India.,Symbiosis Institute of Technology, Symbiosis International (Deemed) University, Lavale, Mulshi, Pune, Maharashtra, 412115, India
| | - Pramod Kumar Pal
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, Bangalore, Karnataka, 560029, India.
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Archer DB, Coombes SA, Chu WT, Chung JW, Burciu RG, Okun MS, Wagle Shukla A, Vaillancourt DE. A widespread visually-sensitive functional network relates to symptoms in essential tremor. Brain 2019; 141:472-485. [PMID: 29293948 DOI: 10.1093/brain/awx338] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 10/21/2017] [Indexed: 12/17/2022] Open
Abstract
Essential tremor is a neurological syndrome of heterogeneous pathology and aetiology that is characterized by tremor primarily in the upper extremities. This tremor is commonly hypothesized to be driven by a single or multiple neural oscillator(s) within the cerebello-thalamo-cortical pathway. Several studies have found an association of blood-oxygen level-dependent (BOLD) signal in the cerebello-thalamo-cortical pathway with essential tremor, but there is behavioural evidence that also points to the possibility that the severity of tremor could be influenced by visual feedback. Here, we directly manipulated visual feedback during a functional MRI grip force task in patients with essential tremor and control participants, and hypothesized that an increase in visual feedback would exacerbate tremor in the 4-12 Hz range in essential tremor patients. Further, we hypothesized that this exacerbation of tremor would be associated with dysfunctional changes in BOLD signal and entropy within, and beyond, the cerebello-thalamo-cortical pathway. We found that increases in visual feedback increased tremor in the 4-12 Hz range in essential tremor patients, and this increase in tremor was associated with abnormal changes in BOLD amplitude and entropy in regions within the cerebello-thalamo-motor cortical pathway, and extended to visual and parietal areas. To determine if the tremor severity was associated with single or multiple brain region(s), we conducted a birectional stepwise multiple regression analysis, and found that a widespread functional network extending beyond the cerebello-thalamo-motor cortical pathway was associated with changes in tremor severity measured during the imaging protocol. Further, this same network was associated with clinical tremor severity measured with the Fahn, Tolosa, Marin Tremor Rating Scale, suggesting this network is clinically relevant. Since increased visual feedback also reduced force error, this network was evaluated in relation to force error but the model was not significant, indicating it is associated with force tremor but not force error. This study therefore provides new evidence that a widespread functional network is associated with the severity of tremor in patients with essential tremor measured simultaneously at the hand during functional imaging, and is also associated with the clinical severity of tremor. These findings support the idea that the severity of tremor is exacerbated by increased visual feedback, suggesting that designers of new computing technologies should consider using lower visual feedback levels to reduce tremor in essential tremor.
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Affiliation(s)
- Derek B Archer
- Laboratory for Rehabilitation Neuroscience, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Stephen A Coombes
- Laboratory for Rehabilitation Neuroscience, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Winston T Chu
- Laboratory for Rehabilitation Neuroscience, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA.,Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Jae Woo Chung
- Laboratory for Rehabilitation Neuroscience, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Roxana G Burciu
- Laboratory for Rehabilitation Neuroscience, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Michael S Okun
- Department of Neurology and Center for Movement Disorders and Neurorestoration, College of Medicine, University of Florida, Gainesville, FL, USA
| | - Aparna Wagle Shukla
- Department of Neurology and Center for Movement Disorders and Neurorestoration, College of Medicine, University of Florida, Gainesville, FL, USA
| | - David E Vaillancourt
- Laboratory for Rehabilitation Neuroscience, Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA.,Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA.,Department of Neurology and Center for Movement Disorders and Neurorestoration, College of Medicine, University of Florida, Gainesville, FL, USA
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No reliable gray matter changes in essential tremor. Neurol Sci 2019; 40:2051-2063. [PMID: 31115799 DOI: 10.1007/s10072-019-03933-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 05/09/2019] [Indexed: 12/18/2022]
Abstract
BACKGROUND Voxel-based morphometry (VBM) has been used to study human brain gray matter (GM) alterations in essential tremor (ET) for over one decade. However, the literature revealed heterogeneous findings. METHODS We therefore conducted a coordinate-based meta-analysis to synthesize the VBM studies to examine which brain regions show the most reliable GM alterations in patients with ET relative to healthy controls. RESULTS A total of 16 original VBM studies, comprising 387 patients with ET and 355 healthy controls, were included in this meta-analysis. This quantitative meta-analysis revealed no evidence of robust and reliable alterations in regional brain GM structures in ET. Meta-regression analyses indicate that many moderators (e.g., MR field strength, statistical methodology, age, onset age, gender, illness severity, illness duration, and family history) account for some of the heterogeneity in GM across studies. CONCLUSIONS High heterogeneity in GM alterations across studies may reflect true heterogeneity in ET regarding the clinic, etiology, and pathology, as well as possibly the VBM methodological variations. Currently, this heterogeneity limits the use of VBM as a reliable tool to distinguish ET from healthy controls. In order to improve reproducibility of VBM results in ET, future research may benefit from increasing the sample size, comprehensively subtyping ET phenotypes, and using well-designed and standardized imaging acquisition and analytical protocols. Furthermore, data sharing should be considered as a high priority.
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Chiang VL, Chao ST, Tuleasca C, Foote MC, Lee CC, Mathieu D, Soliman H, Sahgal A. Proceedings of the 2018 next-generation Gamma Knife research meeting. J Neurosurg 2018; 129:5-9. [PMID: 30544302 DOI: 10.3171/2018.7.gks181206] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 07/19/2018] [Indexed: 11/06/2022]
Abstract
In order to determine what areas of research are a clinical priority, a small group of young Gamma Knife investigators was invited to attend a workshop discussion at the 19th International Leksell Gamma Knife Society Meeting. Two areas of interest and the need for future radiosurgical research involving multiple institutions were identified by the young investigators working group: 1) the development of additional imaging sequences to guide the understanding, treatment, and outcome tracking of diseases such as tremor, radiation necrosis, and AVM; and 2) trials to clarify the role of hypofractionation versus single-fraction radiosurgery in the treatment of large lesions such as brain metastases, postoperative cavities, and meningiomas.
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Affiliation(s)
- Veronica L Chiang
- 1Department of Neurosurgery, Yale University, New Haven, Connecticut
| | - Samuel T Chao
- 2Department of Radiation Oncology, Cleveland Clinic, Cleveland, Ohio
| | - Constantin Tuleasca
- 3Department of Clinical Neurosciences, Neurosurgery Service and Gamma Knife Center, Lausanne University Hospital (CHUV); Faculty of Biology and Medicine (FBM), University of Lausanne; and Signal Processing Laboratory (EPFL), Swiss Federal Institute of Technology, Lausanne, Switzerland
| | - Matthew C Foote
- 4Department of Radiation Oncology, Princess Alexandra Hospital, University of Queensland, Brisbane, Queensland, Australia
| | - Cheng-Chia Lee
- 5Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital; and School of Medicine, National Yan-Min University, Taipei, Taiwan
| | - David Mathieu
- 6Department of Neurosurgery, Department of Surgery, Université de Sherbrooke, Quebec, Canada; and
| | - Hany Soliman
- 7Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Ontario, Canada
| | - Arjun Sahgal
- 7Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Ontario, Canada
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Abstract
Even before the success of combined positron emission tomography and computed tomography (PET/CT), the neuroimaging community was conceiving the idea to integrate the positron emission tomography (PET), with very high molecular quantitative data but low spatial resolution, and magnetic resonance imaging (MRI), with high spatial resolution. Several technical limitations have delayed the use of a hybrid scanner in neuroimaging studies, including the full integration of the PET detector ring within the MRI system, the optimization of data acquisition, and the implementation of reliable methods for PET attenuation, motion correction, and joint image reconstruction. To be valid and useful in clinical and research settings, this instrument should be able to simultaneously acquire PET and MRI, and generate quantitative parametric PET images comparable to PET-CT. While post hoc co-registration of combined PET and MRI data acquired separately became the most reliable technique for the generation of "fused" PET-MRI images, only hybrid PET-MRI approach allows merging these measurements naturally and correlating them in a temporal manner. Furthermore, hybrid PET-MRI represents the most accurate tool to investigate in vivo the interplay between molecular and functional aspects of brain pathophysiology. Hybrid PET-MRI technology is still in the early stages in the movement disorders field, due to the limited availability of scanners with integrated optimized methodological models. This technology is ideally suited to investigate interactions between resting-state functional/arterial spin labeling MRI and [18F]FDG PET glucose metabolism in the evaluation of the brain "hubs" particularly vulnerable to neurodegeneration, areas with a high degree of connectivity and associated with an efficient synaptic neurotransmission. In Parkinson's disease, hybrid PET-MRI is also the ideal instrument to deeper explore the relationship between resting-state functional MRI and dopamine release at [11C]raclopride PET challenge, in the identification of early drug-naïve Parkinson's disease patients at higher risk of motor complications and in the evaluation of the efficacy of novel neuroprotective treatment able to restore at the same time the altered resting state and the release of dopamine. In this chapter, we discuss the key methodological aspects of hybrid PET-MRI; the evidence in movement disorders of the key resting-state functional and perfusion MRI; [18F]FDG PET and [11C]raclopride PET challenge studies; the potential advantages of using hybrid PET-MRI to investigate the pathophysiology of movement disorders and neurodegenerative diseases. Future directions of hybrid PET-MRI will be discussed alongside with up-to-date technological innovations on hybrid systems.
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Distinct cortical responses evoked by electrical stimulation of the thalamic ventral intermediate nucleus and of the subthalamic nucleus. NEUROIMAGE-CLINICAL 2018; 20:1246-1254. [PMID: 30420259 PMCID: PMC6308824 DOI: 10.1016/j.nicl.2018.11.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Revised: 10/27/2018] [Accepted: 11/02/2018] [Indexed: 12/22/2022]
Abstract
Objective To investigate the spatial and temporal pattern of cortical responses evoked by deep brain stimulation (DBS) of the subthalamic nucleus (STN) and ventral intermediate nucleus of the thalamus (VIM). Methods We investigated 7 patients suffering from Essential tremor (ET) and 7 patients with Parkinson's Disease (PD) following the implantation of DBS electrodes (VIM for ET patients, STN for PD patients). Magnetoencephalography (MEG) was used to record cortical responses evoked by electric stimuli that were applied via the DBS electrode in trains of 5 Hz. Dipole fitting was applied to reconstruct the origin of evoked responses. Results Both VIM and STN DBS led to short latency cortical responses at about 1 ms. The pattern of medium and long latency cortical responses following VIM DBS consisted of peaks at 13, 40, 77, and 116 ms. The associated equivalent dipoles were localized within the central sulcus, 3 patients showed an additional response in the cerebellum at 56 ms. STN DBS evoked cortical responses peaking at 4 ms, 11 ms, and 27 ms, respectively. While most dipoles were localized in the pre- or postcentral gyrus, the distribution was less homogenous compared to VIM stimulation and partially included prefrontal brain areas. Conclusion MEG enables localization of cortical responses evoked by DBS of the VIM and the STN, especially in the sensorimotor cortex. Short latency responses of 1 ms suggest cortical modulation which bypasses synaptic transmission, i.e. antidromic activation of corticofugal fiber pathways. Cortical responses evoked by VIM or STN DBS can be precisely described using MEG. Both STN and VIM DBS primarily evoke cortical responses within the sensorimotor region. Short latency responses of 1 ms both observed in VIM and STN DBS suggest antidromic activation of corticofugal fibers.
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Roy A, Coombes SA, Chung JW, Archer DB, Okun MS, Hess CW, Wagle Shukla A, Vaillancourt DE. Cortical dynamics within and between parietal and motor cortex in essential tremor. Mov Disord 2018; 34:95-104. [PMID: 30345712 DOI: 10.1002/mds.27522] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 09/08/2018] [Accepted: 09/12/2018] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Evidence from functional imaging in essential tremor suggests that activity within parietal and motor cortices may be associated with worsening of tremor at increased visual feedback. OBJECTIVES Examine how cortical oscillations within these regions and the connectivity between these regions is associated with worsening of tremor in essential tremor in response to high visual feedback. METHOD The study included 24 essential tremor participants and 17 controls. We measured cortical activity and tremor magnitude at low and high feedback conditions. Cortical activity was measured using high-density electroencephalogram and isolated using source localization. RESULTS Changes in power across feedback in the 4-12 Hz and 12-30 Hz bands were reduced within the contralateral motor cortex of essential tremor patients compared to controls. The 12-30 Hz bidirectional connectivity between the parietal and contralateral motor cortex was decreased in essential tremor patients. Worsening of tremor from low to high visual feedback was associated with 4-12 Hz activity in contralateral motor cortex. The greatest separation between groups was found when using the difference of the contralateral motor cortex activity at high and low feedback, rather than either feedback condition alone. CONCLUSION Our findings provide new evidence that tremor in essential tremor is associated with reduced power across feedback in the motor cortex and reduced connectivity between the parietal and motor cortices. Combined with previous work on the cerebellar-thalamo-cortical motor circuit, our findings suggest that the network level disturbances associated with essential tremor extend to the cortico-cortical pathway between the parietal cortex and motor cortex. © 2018 International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Arnab Roy
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Stephen A Coombes
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Jae Woo Chung
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Derek B Archer
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA
| | - Michael S Okun
- Department of Neurology and Fixel Center for Neurological Diseases and the Program for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, USA
| | - Christopher W Hess
- Department of Neurology and Fixel Center for Neurological Diseases and the Program for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, USA
| | - Aparna Wagle Shukla
- Department of Neurology and Fixel Center for Neurological Diseases and the Program for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, USA
| | - David E Vaillancourt
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA.,Department of Neurology and Fixel Center for Neurological Diseases and the Program for Movement Disorders and Neurorestoration, University of Florida, Gainesville, Florida, USA.,Department of Biomedical Engineering, University of Florida, Gainesville, Florida, USA
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Sazci A, Uren N, Idrisoglu HA, Ergul E. The rs2228570 Variant of the Vitamin D Receptor Gene is Associated with Essential Tremor. Neurosci Bull 2018; 35:362-364. [PMID: 30225763 DOI: 10.1007/s12264-018-0287-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 05/26/2018] [Indexed: 11/24/2022] Open
Affiliation(s)
- Ali Sazci
- Department of Medical Biology and Genetics, Faculty of Medicine, University of Kocaeli, 41380, Kocaeli, Turkey.
| | - Nihal Uren
- Department of Medical Biology and Genetics, Faculty of Medicine, University of Kocaeli, 41380, Kocaeli, Turkey
| | - Halil Atilla Idrisoglu
- Department of Neurology, Istanbul Faculty of Medicine, University of Istanbul, Capa, 34260, Istanbul, Turkey
| | - Emel Ergul
- Department of Medical Biology and Genetics, Faculty of Medicine, University of Kocaeli, 41380, Kocaeli, Turkey
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Tuleasca C, Najdenovska E, Régis J, Witjas T, Girard N, Champoudry J, Faouzi M, Thiran JP, Cuadra MB, Levivier M, Van De Ville D. Pretherapeutic Motor Thalamus Resting-State Functional Connectivity with Visual Areas Predicts Tremor Arrest After Thalamotomy for Essential Tremor: Tracing the Cerebello-thalamo-visuo-motor Network. World Neurosurg 2018; 117:e438-e449. [DOI: 10.1016/j.wneu.2018.06.049] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 06/06/2018] [Accepted: 06/08/2018] [Indexed: 11/17/2022]
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Nestrasil I, Svatkova A, Rudser KD, Chityala R, Wakumoto A, Mueller BA, Bednařík P, Tuite P, Wu X, Bushara K. White matter measures correlate with essential tremor severity-A pilot diffusion tensor imaging study. Brain Behav 2018; 8:e01039. [PMID: 29964316 PMCID: PMC6085909 DOI: 10.1002/brb3.1039] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 05/15/2018] [Accepted: 06/04/2018] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND An evolving pathophysiological concept of essential tremor (ET) points to diffuse brain network involvement, which emphasizes the need to investigate white matter (WM) changes associated with motor symptoms of ET. OBJECTIVES To investigate ET-related WM changes and WM correlates of tremor severity using tremor clinical rating scales and accelerometry. METHODS Tract-based spatial statistics (TBSS) approach was utilized to compare 3 Tesla diffusion tensor imaging (DTI) data from 12 ET patients and 10 age- and gender-matched healthy individuals. Clinical scales, tremor frequency and amplitude as measured by accelerometry were correlated with DTI data. RESULTS ET patients demonstrated mean (MD) and radial diffusivity (RD) abnormalities in tracts involved in primary and associative motor functions such as bilateral corticospinal tracts, the superior longitudinal fascicles, and the corpus callosum but also in nonmotor regions including the inferior fronto-occipital and longitudinal fascicles, cingulum bundles, anterior thalamic radiations, and uncinate fascicles. A combined tremor frequency and amplitude score correlated with RD and MD in extensive WM areas, which partially overlapped the regions that were associated with tremor frequency. No significant relationship was found between DTI measures and clinical rating scales scores. CONCLUSIONS The results show that ET-related diffusion WM changes and their correlates with tremor severity are preferentially located in the primary and associative motor areas. In contrast, a relationship between WM was not detected with clinical rating scales. Accelerometry parameters may, therefore, serve as a potentially useful clinical measures that relate to WM deficits in ET.
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Affiliation(s)
- Igor Nestrasil
- Division of Clinical Behavioral NeuroscienceDepartment of PediatricsUniversity of MinnesotaMinneapolisMinnesota
| | - Alena Svatkova
- Division of Clinical Behavioral NeuroscienceDepartment of PediatricsUniversity of MinnesotaMinneapolisMinnesota
- Department of Medicine III, Clinical Division of Endocrinology and MetabolismMedical University of ViennaViennaAustria
- Multimodal and Functional Neuroimaging Research GroupCentral European Institute of TechnologyMasaryk UniversityBrnoCzech Republic
| | - Kyle D. Rudser
- Division of BiostatisticsUniversity of MinnesotaMinneapolisMinnesota
| | | | - Amy Wakumoto
- Division of Clinical Behavioral NeuroscienceDepartment of PediatricsUniversity of MinnesotaMinneapolisMinnesota
| | - Bryon A. Mueller
- Department of PsychiatryUniversity of MinnesotaMinneapolisMinnesota
| | - Petr Bednařík
- Multimodal and Functional Neuroimaging Research GroupCentral European Institute of TechnologyMasaryk UniversityBrnoCzech Republic
- Department of RadiologyCenter for Magnetic Resonance ResearchUniversity of MinnesotaMinneapolisMinnesota
- High Field MR CentreDepartment of Biomedical Imaging and Image‐guided TherapyMedical University of ViennaViennaAustria
| | - Paul Tuite
- Department of NeurologyUniversity of MinnesotaMinneapolisMinnesota
| | - Xiang Wu
- Psychology DepartmentSun Yet‐Sen UniversityGuangzhouGuangdongChina
| | - Khalaf Bushara
- Department of NeurologyUniversity of MinnesotaMinneapolisMinnesota
- Neurology ServiceVeterans Affairs Medical CenterMinneapolisMinnesota
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Resting-state fMRI study on drug-naive patients of essential tremor with and without head tremor. Sci Rep 2018; 8:10580. [PMID: 30002390 PMCID: PMC6043592 DOI: 10.1038/s41598-018-28778-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 06/26/2018] [Indexed: 02/05/2023] Open
Abstract
This study used resting-state functional MRI (r-fMRI) to evaluate intrinsic brain activity in drug-naive patients with essential tremor (ET) with and without head tremor. We enrolled 20 patients with ET with hand and head tremor (h-ET), 27 patients with ET without head tremor (a-ET), and 27 healthy controls (HCs). All participants underwent r-fMRI scans on a 3-T MR system. The amplitude of low-frequency fluctuation (ALFF) of blood oxygen level-dependent signals was used to characterize regional cerebral function. We identified increased ALFF value in the bilateral posterior lobe of cerebellum in the h-ET patients relative to a-ET and HCs and demonstrated that h-ET is related to abnormalities in the cerebello-cortical areas, while the a-ET is related to abnormalities in the thalamo-cortical areas. In addition, we observed the ALFF abnormality in the cerebellum (left cerebellum VIII and right cerebellum VI) correlated with the tremor score in h-ET patients and abnormal ALFF in the left precentral gyrus correlated with the age at onset and disease duration in h-ET patients. These findings may be helpful for facilitating further understanding of the potential mechanisms underlying different subtypes of ET.
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Tian Q, Wintermark M, Jeffrey Elias W, Ghanouni P, Halpern CH, Henderson JM, Huss DS, Goubran M, Thaler C, Airan R, Zeineh M, Pauly KB, McNab JA. Diffusion MRI tractography for improved transcranial MRI-guided focused ultrasound thalamotomy targeting for essential tremor. NEUROIMAGE-CLINICAL 2018; 19:572-580. [PMID: 29984165 PMCID: PMC6029558 DOI: 10.1016/j.nicl.2018.05.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 05/03/2018] [Accepted: 05/08/2018] [Indexed: 01/07/2023]
Abstract
Purpose To evaluate the use of diffusion magnetic resonance imaging (MRI) tractography for neurosurgical guidance of transcranial MRI-guided focused ultrasound (tcMRgFUS) thalamotomy for essential tremor (ET). Materials and methods Eight patients with medication-refractory ET were treated with tcMRgFUS targeting the ventral intermediate nucleus (Vim) of the thalamus contralateral to their dominant hand. Diffusion and structural MRI data and clinical evaluations were acquired pre-treatment and post-treatment. To identify the optimal target location, tractography was performed on pre-treatment diffusion MRI data between the treated thalamus and the hand-knob region of the ipsilateral motor cortex, the entire ipsilateral motor cortex and the contralateral dentate nucleus. The tractography-identified locations were compared to the lesion location delineated on 1 year post-treatment T2-weighted MR image. Their overlap was correlated with the clinical outcomes measured by the percentage change of the Clinical Rating Scale for Tremor scores acquired pre-treatment, as well as 1 month, 3 months, 6 months and 1 year post-treatment. Results The probabilistic tractography was consistent from subject-to-subject and followed the expected anatomy of the thalamocortical radiation and the dentatothalamic tract. Higher overlap between the tractography-identified location and the tcMRgFUS treatment-induced lesion highly correlated with better treatment outcome (r = −0.929, −0.75, −0.643, p = 0.00675, 0.0663, 0.139 for the tractography between the treated thalamus and the hand-knob region of the ipsilateral motor cortex, the entire ipsilateral motor cortex and the contralateral dentate nucleus, respectively, at 1 year post-treatment). The correlation for the tractography between the treated thalamus and the hand-knob region of the ipsilateral motor cortex is the highest for all time points (r = −0.719, −0.976, −0.707, −0.929, p = 0.0519, 0.000397, 0.0595, 0.00675 at 1 month, 3 months, 6 months and 1 year post-treatment, respectively). Conclusion Our data support the use of diffusion tractography as a complementary approach to current targeting methods for tcMRgFUS thalamotomy. Retrospectively used tractography to define a target for MRgFUS thalamotomy for ET. Larger overlap between tractography and lesion correlates with better outcomes. Strongest correlations for tract between the thalamus and motor hand-knob region Diffusion tractography is a complementary approach to current targeting methods.
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Affiliation(s)
- Qiyuan Tian
- Department of Electrical Engineering, Stanford University, Stanford, CA, United States; Department of Radiology, Stanford University, Stanford, CA, United States.
| | - Max Wintermark
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - W Jeffrey Elias
- Department of Neurosurgery, University of Virginia, Charlottesville, VA, United States
| | - Pejman Ghanouni
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Casey H Halpern
- Department of Neurosurgery, Stanford University, Stanford, CA, United States
| | - Jaimie M Henderson
- Department of Neurosurgery, Stanford University, Stanford, CA, United States
| | - Diane S Huss
- Department of Physical Therapy, University of Virginia, Charlottesville, VA, United States
| | - Maged Goubran
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Christian Thaler
- Department of Radiology, Stanford University, Stanford, CA, United States; Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Raag Airan
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Michael Zeineh
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Kim Butts Pauly
- Department of Electrical Engineering, Stanford University, Stanford, CA, United States; Department of Radiology, Stanford University, Stanford, CA, United States
| | - Jennifer A McNab
- Department of Radiology, Stanford University, Stanford, CA, United States
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Tuleasca C, Najdenovska E, Régis J, Witjas T, Girard N, Champoudry J, Faouzi M, Thiran JP, Cuadra MB, Levivier M, Van De Ville D. Ventrolateral Motor Thalamus Abnormal Connectivity in Essential Tremor Before and After Thalamotomy: A Resting-State Functional Magnetic Resonance Imaging Study. World Neurosurg 2018; 113:e453-e464. [DOI: 10.1016/j.wneu.2018.02.055] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 02/08/2018] [Accepted: 02/09/2018] [Indexed: 01/30/2023]
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Tuleasca C, Najdenovska E, Régis J, Witjas T, Girard N, Champoudry J, Faouzi M, Thiran JP, Bach Cuadra M, Levivier M, Van De Ville D. Pretherapeutic functional neuroimaging predicts tremor arrest after thalamotomy. Acta Neurol Scand 2018; 137:500-508. [PMID: 29315459 DOI: 10.1111/ane.12891] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/08/2017] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Essential tremor (ET) represents the most common movement disorder. Drug-resistant ET can benefit from standard stereotactic procedures (deep brain stimulation or radiofrequency thalamotomy) or alternatively minimally invasive high-focused ultrasound or radiosurgery. All aim at same target, thalamic ventro-intermediate nucleus (Vim). METHODS The study included a cohort of 17 consecutive patients, with ET, treated only with left unilateral stereotactic radiosurgical thalamotomy (SRS-T) between September 2014 and August 2015. The mean time to tremor improvement was 3.32 months (SD 2.7, 0.5-10). Neuroimaging data were collected at baseline (n = 17). Standard tremor scores, including activities of daily living (ADL) and tremor score on treated hand (TSTH), were completed pretherapeutically and 1 year later. We further correlate these scores with baseline inter-connectivity in twenty major large-scale brain networks. RESULTS We report as predictive three networks, with the interconnected statistically significant clusters: primary motor cortex interconnected with inferior olivary nucleus, bilateral thalamus interconnected with motor cerebellum lobule V2 (ADL), and anterior default-mode network interconnected with Brodmann area 103 (TSTH). For all, more positive pretherapeutic interconnectivity correlated with higher drop in points on the respective scores. Age, disease duration, or time-to-response after SRS-T were not statistically correlated with pretherapeutic brain connectivity measures (P > .05). The same applied to pretherapeutic tremor scores, after using the same methodology described above. CONCLUSIONS Our findings have clinical implications for predicting clinical response after SRS-T. Here, using pretherapeutic magnetic resonance imaging and data processing without prior hypothesis, we show that pretherapeutic network(s) interconnectivity strength predicts tremor arrest in drug-naïve ET, following stereotactic radiosurgical thalamotomy.
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Affiliation(s)
- C. Tuleasca
- Neurosurgery Service and Gamma Knife Center; Centre Hospitalier Universitaire Vaudois (CHUV); Lausanne Switzerland
- Medical Image Analysis Laboratory (MIAL) and Department of Radiology-Center of Biomedical Imaging (CIBM); Centre Hospitalier Universitaire Vaudois; Lausanne Switzerland
- Signal Processing Laboratory (LTS 5); Ecole Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
- Faculty of Biology and Medicine; University of Lausanne; Lausanne Switzerland
| | - E. Najdenovska
- Medical Image Analysis Laboratory (MIAL) and Department of Radiology-Center of Biomedical Imaging (CIBM); Centre Hospitalier Universitaire Vaudois; Lausanne Switzerland
| | - J. Régis
- Stereotactic and Functional Neurosurgery Service and Gamma Knife Unit; CHU Timone; Marseille France
| | - T. Witjas
- Neurology Department; CHU Timone; Marseille France
| | - N. Girard
- AMU, CRMBM UMR CNRS 7339; Faculté de Médecine et APHM; Department of Diagnostic and Interventionnal Neuroradiology; Hopital Timone; Marseille France
| | - J. Champoudry
- Stereotactic and Functional Neurosurgery Service and Gamma Knife Unit; CHU Timone; Marseille France
| | - M. Faouzi
- Center for Clinical Epidemiology; Institute of Social and Preventive Medicine; Lausanne Switzerland
| | - J.-P. Thiran
- Signal Processing Laboratory (LTS 5); Ecole Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
- Faculty of Biology and Medicine; University of Lausanne; Lausanne Switzerland
- Department of Radiology; Centre Hospitalier Universitaire Vaudois; Lausanne Switzerland
| | - M. Bach Cuadra
- Medical Image Analysis Laboratory (MIAL) and Department of Radiology-Center of Biomedical Imaging (CIBM); Centre Hospitalier Universitaire Vaudois; Lausanne Switzerland
- Signal Processing Laboratory (LTS 5); Ecole Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
| | - M. Levivier
- Neurosurgery Service and Gamma Knife Center; Centre Hospitalier Universitaire Vaudois (CHUV); Lausanne Switzerland
- Faculty of Biology and Medicine; University of Lausanne; Lausanne Switzerland
| | - D. Van De Ville
- Faculty of Medicine; University of Geneva; Geneva Switzerland
- Medical Image Processing Laboratory; Ecole Polytechnique Fédérale de Lausanne (EPFL); Lausanne Switzerland
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Clinical response to Vim's thalamic stereotactic radiosurgery for essential tremor is associated with distinctive functional connectivity patterns. Acta Neurochir (Wien) 2018; 160:611-624. [PMID: 29335882 DOI: 10.1007/s00701-017-3456-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 12/26/2017] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Essential tremor (ET) is the most common movement disorder. Drug-resistant ET can benefit from standard surgical stereotactic procedures (deep brain stimulation, thalamotomy) or minimally invasive high-intensity focused ultrasound (HIFU) or stereotactic radiosurgical thalamotomy (SRS-T). Resting-state fMRI (rs-fMRI) is a non-invasive imaging method acquired in absence of a task. We examined whether rs-fMRI correlates with tremor score on the treated hand (TSTH) improvement 1 year after SRS-T. METHODS We included 17 consecutive patients treated with left unilateral SRS-T in Marseille, France. Tremor score evaluation and rs-fMRI were acquired at baseline and 1 year after SRS-T. Resting-state data (34 scans) were analyzed without a priori hypothesis, in Lausanne, Switzerland. Based on degree of improvement in TSTH, to consider SRS-T at least as effective as medication, we separated two groups: 1, ≤ 50% (n = 6, 35.3%); 2, > 50% (n = 11, 64.7%). They did not differ statistically by age (p = 0.86), duration of symptoms (p = 0.41), or lesion volume at 1 year (p = 0.06). RESULTS We report TSTH improvement correlated with interconnectivity strength between salience network with the left claustrum and putamen, as well as between bilateral motor cortices, frontal eye fields and left cerebellum lobule VI with right visual association area (the former also with lesion volume). Longitudinal changes showed additional associations in interconnectivity strength between right dorsal attention network with ventro-lateral prefrontal cortex and a reminiscent salience network with fusiform gyrus. CONCLUSIONS Brain connectivity measured by resting-state fMRI relates to clinical response after SRS-T. Relevant networks are visual, motor, and attention. Interconnectivity between visual and motor areas is a novel finding, revealing implication in movement sensory guidance.
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Tuleasca C, Régis J, Najdenovska E, Witjas T, Girard N, Champoudry J, Faouzi M, Thiran JP, Cuadra MB, Levivier M, Van De Ville D. Pretherapeutic Functional Imaging Allows Prediction of Head Tremor Arrest After Thalamotomy for Essential Tremor: The Role of Altered Interconnectivity Between Thalamolimbic and Supplementary Motor Circuits. World Neurosurg 2018; 112:e479-e488. [PMID: 29410136 DOI: 10.1016/j.wneu.2018.01.063] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/05/2018] [Accepted: 01/11/2018] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To correlate pretherapeutic resting-state functional magnetic resonance imaging (rs-fMRI) measures with pretherapeutic head tremor presence and/or further improvement 1 year after stereotactic radiosurgical thalamotomy (SRS-T) for essential tremor (ET). METHODS We prospectively collected head tremor scores (range, 0-3) and rs-fMRI data for a cohort of 17 consecutive ET patients in pretherapeutic and 1 year after SRS-T states. We additionally acquired rs-fMRI data for a healthy control (HC) group (n = 12). Group-level independent component analysis (n = 17 for pretherapeutic rs-fMRI) was applied to decompose neuroimaging data into 20 large-scale brain networks using a standard approach. Through spatial regression, we projected 1 year after SRS-T and HC rs-fMRI time points, on the same 20 brain networks. RESULTS Pretherapeutic interconnectivity (IC) strength between the network including bilateral thalamus and limbic system with left supplementary motor area predicted head tremor improvement at 1 year after SRS-T (family-wise corrected P < 0.001, cluster size Kc = 146). For the statistically significant cluster, IC strength was strongest in HCs (mean, 4.6; median, 3.8) compared with pre- (mean, 0.1; median, 0.2) or posttherapeutic (mean, -0.2; median, 0.09) states. CONCLUSIONS Baseline measures of IC between bilateral thalamus and limbic system with left supplementary motor area may predict head tremor arrest after thalamotomy. However, procedures such as SRS-T, for this particular clinical feature, do not align patients to HCs in terms of functional brain connectivity. We postulate that supplementary motor area is modulating head tremor appearance, by abnormal connectivity with the thalamolimbic system.
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Affiliation(s)
- Constantin Tuleasca
- Centre Hospitalier Universitaire Vaudois, Neurosurgery Service and Gamma Knife Center, Lausanne, Switzerland; Signal Processing Laboratory (LTS5), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
| | - Jean Régis
- Stereotactic and Functional Neurosurgery Service and Gamma Knife Unit, CHU Timone, Marseille, France
| | - Elena Najdenovska
- Medical Image Analysis Laboratory and Department of Radiology-Center of Biomedical Imaging, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | | | - Nadine Girard
- Department of Diagnostic and Interventional Neuroradiology, AMU, CRMBM UMR CNRS 7339, Faculté de Médecine et APHM, Hopital Timone, Marseille, France
| | - Jérôme Champoudry
- Stereotactic and Functional Neurosurgery Service and Gamma Knife Unit, CHU Timone, Marseille, France
| | - Mohamed Faouzi
- Centre for Clinical Epidemiology, Institute of Social and Preventive Medicine, Lausanne, Switzerland
| | - Jean-Philippe Thiran
- Signal Processing Laboratory (LTS5), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland; Department of Radiology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Meritxell Bach Cuadra
- Medical Image Analysis Laboratory and Department of Radiology-Center of Biomedical Imaging, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland; Signal Processing Laboratory (LTS5), Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Marc Levivier
- Centre Hospitalier Universitaire Vaudois, Neurosurgery Service and Gamma Knife Center, Lausanne, Switzerland; Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Dimitri Van De Ville
- Faculty of Medicine, University of Geneva, Geneva, Switzerland; Medical Image Processing Laboratory, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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Hopfner F, Helmich RC. The etiology of essential tremor: Genes versus environment. Parkinsonism Relat Disord 2018; 46 Suppl 1:S92-S96. [DOI: 10.1016/j.parkreldis.2017.07.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Accepted: 07/16/2017] [Indexed: 12/18/2022]
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Tsolaki E, Downes A, Speier W, Elias WJ, Pouratian N. The potential value of probabilistic tractography-based for MR-guided focused ultrasound thalamotomy for essential tremor. NEUROIMAGE-CLINICAL 2017. [PMID: 29527503 PMCID: PMC5842733 DOI: 10.1016/j.nicl.2017.12.018] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Magnetic Resonance-guided Focused UltraSound (MRgFUS) offers an incisionless approach to treat essential tremor (ET). Due to lack of evident internal anatomy on traditional structural imaging, indirect targeting must still be used to localize the lesion. Here, we investigate the potential predictive value of probabilistic tractography guided thalamic targeting by defining how tractography-defined targets, lesion size and location, and clinical outcomes interrelate. MR imaging and clinical outcomes from 12 ET patients that underwent MRgFUS thalamotomy in a pilot study at the University of Virginia were evaluated in this analysis. FSL was used to evaluate each patient's voxel-wise thalamic connectivity with FreeSurfer generated pre- and post-central gyrus targets, to generate thalamic target maps. Using Receiver Operating Characteristic curves, the overlap between these thalamic target maps and the MRgFUS lesion was systematically evaluated relative to clinical outcome. To further define the connectivity characteristics of effective MRgFUS thalamotomy lesions, we evaluated whole brain probabilistic tractography of lesions (using post-treatment imaging to define the lesion pre-treatment diffusion tensor MRI). The structural connectivity difference was explored between subjects with the best clinical outcome relative to all others. Ten of twelve patients presented high percentage of overlapping between connectivity-based thalamic segmentation maps and lesion area. The improvement of clinical score was predicted (AUC: 0.80) using the volume of intersection between the thalamic target (precentral gyrus) map and MRgFUS induced lesion as feature. The main structural differences between those with different magnitudes of response were observed in connectivity to the pre- and post-central gyri and brainstem/cerebellum. MRgFUS thalamotomy lesions characterized by strong structural connectivity to precentral gyrus demonstrated better responses in a cohort of patients treated with MRgFUS for ET. The intersection between lesion and thalamic-connectivity maps to motor - sensory targets proved to be effective in predicting the response to the therapy. These imaging techniques can be used to increase the efficacy and consistency of outcomes with MRgFUS and potentially shorten treatment times by identifying optimal targets in advance of treatment. MRgFUS thalamic lesions with connecting to peri-rolandic cortices and cerebellum demonstrate superior outcomes. The overlap of MRgFUS induced lesion and tractography-based thalamic segmentation correlates with clinical improvement. Probabilistic tractography-guided thalamic segmentation may be useful to increase MRgFUS efficacy and consistency.
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Affiliation(s)
- Evangelia Tsolaki
- Department of Neurosurgery David Geffen School of Medicine, UCLA, Los Angeles, CA, USA.
| | - Angela Downes
- Department of Neurosurgery David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - William Speier
- Department of Neurosurgery David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - W Jeff Elias
- Department of Neurosurgery, University of Virginia, Charlottesville, VA, USA
| | - Nader Pouratian
- Department of Neurosurgery David Geffen School of Medicine, UCLA, Los Angeles, CA, USA; Brain Research Institute David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
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Lehn AC, O'Gorman C, Olson S, Salari M. Thalamic Ventral Intermediate Nucleus Deep Brain Stimulation for Orthostatic Tremor. TREMOR AND OTHER HYPERKINETIC MOVEMENTS (NEW YORK, N.Y.) 2017; 7:479. [PMID: 28983421 PMCID: PMC5628322 DOI: 10.7916/d8280jhr] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Accepted: 06/28/2017] [Indexed: 12/02/2022]
Abstract
Background Orthostatic tremor (OT) was first described in 1977. It is characterized by rapid tremor of 13–18 Hz and can be recorded in the lower limbs and trunk muscles. OT remains difficult to treat, although some success has been reported with deep brain stimulation (DBS). Case Report We report a 68‐year‐old male with OT who did not improve significantly after bilateral thalamic stimulation. Discussion Although some patients were described who improved after DBS surgery, more information is needed about the effect of these treatment modalities on OT, ideally in the form of randomized trial data.
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Affiliation(s)
- Alexander C Lehn
- Department of Neurology, Princess Alexandra Hospital, Brisbane, Australia.,School of Medicine, University of Queensland, Brisbane, Australia
| | - Cullen O'Gorman
- Department of Neurology, Princess Alexandra Hospital, Brisbane, Australia.,Griffith University, Gold Coast, Australia
| | - Sarah Olson
- Department of Neurosurgery, Princess Alexandra Hospital, Brisbane, Queensland, Australia
| | - Mehri Salari
- Department of Neurology, School of medicine, Qom University of Medical Science, Qom, Iran
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Mueller K, Jech R, Hoskovcová M, Ulmanová O, Urgošík D, Vymazal J, Růžička E. General and selective brain connectivity alterations in essential tremor: A resting state fMRI study. Neuroimage Clin 2017; 16:468-476. [PMID: 28913163 PMCID: PMC5587870 DOI: 10.1016/j.nicl.2017.06.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 05/22/2017] [Accepted: 06/01/2017] [Indexed: 12/17/2022]
Abstract
Although essential tremor is the most common movement disorder, there is little knowledge about the pathophysiological mechanisms of this disease. Therefore, we explored brain connectivity based on slow spontaneous fluctuations of blood oxygenation level dependent (BOLD) signal in patients with essential tremor (ET). A cohort of 19 ET patients and 23 healthy individuals were scanned in resting condition using functional magnetic resonance imaging (fMRI). General connectivity was assessed by eigenvector centrality (EC) mapping. Selective connectivity was analyzed by correlations of the BOLD signal between the preselected seed regions and all the other brain areas. These measures were then correlated with the tremor severity evaluated by the Fahn-Tolosa-Marin Tremor Rating Scale (FTMTS). Compared to healthy subjects, ET patients were found to have lower EC in the cerebellar hemispheres and higher EC in the anterior cingulate and in the primary motor cortices bilaterally. In patients, the FTMTS score correlated positively with the EC in the putamen. In addition, the FTMTS score correlated positively with selective connectivity between the thalamus and other structures (putamen, pre-supplementary motor area (pre-SMA), parietal cortex), and between the pre-SMA and the putamen. We observed a selective coupling between a number of areas in the sensorimotor network including the basal ganglia and the ventral intermediate nucleus of thalamus, which is widely used as neurosurgical target for tremor treatment. Finally, ET was marked by suppression of general connectivity in the cerebellum, which is in agreement with the concept of ET as a disorder with cerebellar damage.
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Affiliation(s)
- Karsten Mueller
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Robert Jech
- Department of Neurology, Charles University, First Faculty of Medicine and General University Hospital in Prague, Czech Republic
| | - Martina Hoskovcová
- Department of Neurology, Charles University, First Faculty of Medicine and General University Hospital in Prague, Czech Republic
| | - Olga Ulmanová
- Department of Neurology, Charles University, First Faculty of Medicine and General University Hospital in Prague, Czech Republic
| | | | | | - Evžen Růžička
- Department of Neurology, Charles University, First Faculty of Medicine and General University Hospital in Prague, Czech Republic
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Cerasa A, Quattrone A. Linking Essential Tremor to the Cerebellum-Neuroimaging Evidence. THE CEREBELLUM 2017; 15:263-75. [PMID: 26626626 DOI: 10.1007/s12311-015-0739-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Essential tremor (ET) is the most common pathological tremor disorder in the world, and post-mortem evidence has shown that the cerebellum is the most consistent area of pathology in ET. In the last few years, advanced neuroimaging has tried to confirm this evidence. The aim of the present review is to discuss to what extent the evidence provided by this field of study may be generalised. We performed a systematic literature search combining the terms ET with the following keywords: MRI, VBM, MRS, DTI, fMRI, PET and SPECT. We summarised and discussed each study and placed the results in the context of existing knowledge regarding the cerebellar involvement in ET. A total of 51 neuroimaging studies met our search criteria, roughly divided into 19 structural and 32 functional studies. Despite clinical and methodological differences, both functional and structural imaging studies showed similar findings but without defining a clear topography of neurodegeneration. Indeed, the vast majority of studies found functional and structural abnormalities in several parts of the anterior and posterior cerebellar lobules, but it remains to be established to what degree these neural changes contribute to clinical symptoms of ET. Currently, advanced neuroimaging has confirmed the involvement of the cerebellum in pathophysiological processes of ET, although a high variability in results persists. For this reason, the translation of this knowledge into daily clinical practice is again partially limited, although new advanced multivariate neuroimaging approaches (machine-learning) are proving interesting changes of perspective.
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Affiliation(s)
| | - Aldo Quattrone
- IBFM, National Research Council, Catanzaro, CZ, Italy. .,Institute of Neurology, Department of Medical Sciences, University "Magna Graecia", Catanzaro, Italy.
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Knowledge gaps and research recommendations for essential tremor. Parkinsonism Relat Disord 2016; 33:27-35. [PMID: 27769649 DOI: 10.1016/j.parkreldis.2016.10.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Revised: 08/29/2016] [Accepted: 10/01/2016] [Indexed: 12/17/2022]
Abstract
Essential tremor (ET) is a common cause of significant disability, but its etiologies and pathogenesis are poorly understood. Research has been hampered by the variable definition of ET and by non-standardized research approaches. The National Institute of Neurological Disorders and Stroke (USA) invited experts in ET and related fields to discuss current knowledge, controversies, and gaps in our understanding of ET and to develop recommendations for future research. Discussion focused on phenomenology and phenotypes, therapies and clinical trials, pathophysiology, pathology, and genetics. Across all areas, the need for collaborative and coordinated research on a multinational level was expressed. Standardized data collection using common data elements for genetic, clinical, neurophysiological, and pathological studies was recommended. Large cohorts of patients should be studied prospectively to collect bio-samples, characterize the natural history of the clinical syndrome including patient-oriented outcomes, investigate potential etiologies of various phenotypes, and identify pathophysiological mechanisms. In particular, cellular and system-level mechanisms of tremor oscillations should be elucidated because they may yield effective therapeutic targets and biomarkers. A neuropathology consortium was recommended to standardize postmortem analysis and further characterize neuropathological observations in the cerebellum and elsewhere. Furthermore, genome-wide association studies on large patient cohorts (>10,000 patients) may allow the identification of common genes contributing to risk, and whole exome or genome sequencing may enable the identification of genetic risk and causal mutations in cohorts and well-characterized families.
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Zhang S, Chen JM, Kuang L, Cao J, Zhang H, Ai M, Wang W, Zhang SD, Wang SY, Liu SJ, Fang WD. Association between abnormal default mode network activity and suicidality in depressed adolescents. BMC Psychiatry 2016; 16:337. [PMID: 27688124 PMCID: PMC5041526 DOI: 10.1186/s12888-016-1047-7] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 09/20/2016] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Suicide is the second leading cause of death among 15- to 29-year-olds in China, and 60 % of suicidal patients have a history of depression. Previous brain imaging studies have shown that depression and suicide may be associated with abnormal activity in default mode network (DMN) regions. However, no study has specifically investigated the relationship between DMN functional activity and suicidal behavior in depressed individuals. Therefore, in the present study, we directly investigated features of DMN brain activity in adolescent patients with histories of depression and attempted suicide. METHODS A total of 35 sex- and age-matched suicidal depressed patients were compared with 18 non-suicidal depressed patients and 47 healthy controls. We explored functional activity changes in DMN regions that could be associated with suicidal behavior by comparing resting-state functional magnetic resonance imaging (rs-fMRI) signals using independent component analysis (ICA). Scores on six clinical scales that measure depression severity (Hamilton Depression Scale (HDRS) and Beck Depression Inventory (BDI)) and suicidal traits (Barratt Impulsiveness Scale (BIS-11), Suicide Attitude Questionnaire (SAQ), Beck Hopelessness Scale (BHS), and Scale for Suicide Ideation (SSI)) were compared in the three groups. RESULTS Compared with the healthy controls, all of the evaluated depressed patients showed increased functional connectivity in select DMN regions. The suicidal patients showed increased connectivity in the left cerebellum and decreased connectivity in the right posterior cingulate cortex (PCC), whereas the non-suicidal depressed patients showed increased connectivity in the left superior frontal gyrus, left lingual gyrus and right precuneus and decreased connectivity in the left cerebellum. Compared to the non-suicidal patients, the suicidal patients showed increased connectivity in the left cerebellum and the left lingual gyrus and decreased connectivity in the right precuneus. No differences in the scores of any clinical scales were found between the suicidal and non-suicidal depressed patients. CONCLUSIONS Collectively, our results highlight the importance of the DMN in the pathophysiology of depression and suggest that suicidal behavior in depressed adolescents may be related to abnormal functional connectivity in the DMN. In particular, abnormal connectivity in the PCC/precuneus and left cerebellum might be a predictor of suicidal behavior in depressed adolescent patients.
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Affiliation(s)
- Shuang Zhang
- Mental Health Center, University-Town Hospital of Chongqing Medical University, Chongqing, 401331 China
| | - Jian-mei Chen
- Department of Psychiatry, First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016 China
| | - Li Kuang
- Department of Psychiatry, First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China.
| | - Jun Cao
- Department of Psychiatry, First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016 China
| | - Han Zhang
- Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, 310015 China
| | - Ming Ai
- Department of Psychiatry, First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016 China
| | - Wo Wang
- Mental Health Center, University-Town Hospital of Chongqing Medical University, Chongqing, 401331 China
| | - Shu-dong Zhang
- Department of Psychiatry, First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016 China
| | - Su-ya Wang
- Department of Psychiatry, First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016 China
| | - Shi-jing Liu
- Department of Psychiatry, First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016 China
| | - Wei-dong Fang
- Department of Radiology, First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016 China
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Interhemispheric Connectivity Characterizes Cortical Reorganization in Motor-Related Networks After Cerebellar Lesions. THE CEREBELLUM 2016; 16:358-375. [DOI: 10.1007/s12311-016-0811-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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