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Ni R, Straumann N, Fazio S, Dean-Ben XL, Louloudis G, Keller C, Razansky D, Ametamey S, Mu L, Nombela-Arrieta C, Klohs J. Imaging increased metabolism in the spinal cord in mice after middle cerebral artery occlusion. PHOTOACOUSTICS 2023; 32:100532. [PMID: 37645255 PMCID: PMC10461215 DOI: 10.1016/j.pacs.2023.100532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 07/13/2023] [Accepted: 07/13/2023] [Indexed: 08/31/2023]
Abstract
Emerging evidence indicates crosstalk between the brain and hematopoietic system following cerebral ischemia. Here, we investigated metabolism and oxygenation in the spleen and spinal cord in a transient middle cerebral artery occlusion (tMCAO) model. Sham-operated and tMCAO mice underwent [18F]fluorodeoxyglucose (FDG)-positron emission tomography (PET) to assess glucose metabolism. Naïve, sham-operated and tMCAO mice underwent multispectral optoacoustic tomography (MSOT) assisted by quantitative model-based reconstruction and unmixing algorithms for accurate mapping of oxygenation patterns in peripheral tissues at 24 h after reperfusion. We found increased [18F]FDG uptake and reduced MSOT oxygen saturation, indicating hypoxia in the thoracic spinal cord of tMCAO mice compared with sham-operated mice but not in the spleen. Reduced spleen size was observed in tMCAO mice compared with sham-operated mice ex vivo. tMCAO led to an increase in the numbers of mature T cells in femoral bone marrow tissues, concomitant with a stark reduction in these cell subsets in the spleen and peripheral blood. The combination of quantitative PET and MSOT thus enabled observation of hypoxia and increased metabolic activity in the spinal cord of tMCAO mice at 24 h after occlusion compared to sham-operated mice.
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Affiliation(s)
- Ruiqing Ni
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland
- Zentrum für Neurowissenschaften Zurich, Zurich, Switzerland
| | - Nadja Straumann
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
| | - Serana Fazio
- Department of Medical Oncology and Hematology, University and University Hospital Zurich, Zurich, Switzerland
| | - Xose Luis Dean-Ben
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland
| | - Georgios Louloudis
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland
| | - Claudia Keller
- Center for Radiopharmaceutical Sciences ETH, PSI and USZ, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - Daniel Razansky
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland
- Zentrum für Neurowissenschaften Zurich, Zurich, Switzerland
| | - Simon Ametamey
- Center for Radiopharmaceutical Sciences ETH, PSI and USZ, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - Linjing Mu
- Center for Radiopharmaceutical Sciences ETH, PSI and USZ, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich, Switzerland
| | - César Nombela-Arrieta
- Department of Medical Oncology and Hematology, University and University Hospital Zurich, Zurich, Switzerland
| | - Jan Klohs
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, University of Zurich & ETH Zurich, Zurich, Switzerland
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Huo C, Sun Z, Xu G, Li X, Xie H, Song Y, Li Z, Wang Y. fNIRS-based brain functional response to robot-assisted training for upper-limb in stroke patients with hemiplegia. Front Aging Neurosci 2022; 14:1060734. [PMID: 36583188 PMCID: PMC9793407 DOI: 10.3389/fnagi.2022.1060734] [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: 10/03/2022] [Accepted: 11/23/2022] [Indexed: 12/14/2022] Open
Abstract
Background Robot-assisted therapy (RAT) has received considerable attention in stroke motor rehabilitation. Characteristics of brain functional response associated with RAT would provide a theoretical basis for choosing the appropriate protocol for a patient. However, the cortical response induced by RAT remains to be fully elucidated due to the lack of dynamic brain functional assessment tools. Objective To guide the implementation of clinical therapy, this study focused on the brain functional responses induced by RAT in patients with different degrees of motor impairment. Methods A total of 32 stroke patients were classified into a low score group (severe impairment, n = 16) and a high score group (moderate impairment, n = 16) according to the motor function of the upper limb and then underwent RAT training in assistive mode with simultaneous cerebral haemodynamic measurement by functional near-infrared spectroscopy (fNIRS). Functional connectivity (FC) and the hemisphere autonomy index (HAI) were calculated based on the wavelet phase coherence among fNIRS signals covering bilateral prefrontal, motor and occipital areas. Results Specific cortical network response related to RAT was observed in patients with unilateral moderate-to-severe motor deficits in the subacute stage. Compared with patients with moderate dysfunction, patients with severe impairment showed a wide range of significant FC responses in the bilateral hemispheres induced by RAT with the assistive mode, especially task-related involvement of ipsilesional supplementary motor areas. Conclusion Under assisted mode, RAT-related extensive cortical response in patients with severe dysfunction might contribute to brain functional organization during motor performance, which is considered the basic neural substrate of motor-related processes. In contrast, the limited cortical response related to RAT in patients with moderate dysfunction may indicate that the training intensity needs to be adjusted in time according to the brain functional state. fNIRS-based assessment of brain functional response assumes great importance for the customization of an appropriate protocol training in the clinical practice.
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Affiliation(s)
- Congcong Huo
- Rehabilitation Center, Qilu Hospital of Shandong University, Jinan, Shandong, China,Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China,Beijing Key Laboratory of Rehabilitation Technical Aids for Old-Age Disability, National Research Center for Rehabilitation Technical Aids, Beijing, China
| | - Zhifang Sun
- Rehabilitation Center, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Gongcheng Xu
- Rehabilitation Center, Qilu Hospital of Shandong University, Jinan, Shandong, China,Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Xinglou Li
- Rehabilitation Center, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Hui Xie
- Rehabilitation Center, Qilu Hospital of Shandong University, Jinan, Shandong, China,Beijing Advanced Innovation Centre for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Ying Song
- Rehabilitation Center, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Zengyong Li
- Beijing Key Laboratory of Rehabilitation Technical Aids for Old-Age Disability, National Research Center for Rehabilitation Technical Aids, Beijing, China,Key Laboratory of Rehabilitation Aids Technology and System of the Ministry of Civil Affairs, Beijing, China,*Correspondence: Zengyong Li,
| | - Yonghui Wang
- Rehabilitation Center, Qilu Hospital of Shandong University, Jinan, Shandong, China,Yonghui Wang,
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Nguyen AM, Huynh NT, Nguyen TTP. Intraoperative cortical and subcortical stimulation for lesions related to eloquent motor cortex and corticospinal tract in a developing country. INTERDISCIPLINARY NEUROSURGERY 2022. [DOI: 10.1016/j.inat.2022.101601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Kojima S, Morishita S, Hotta K, Qin W, Usui N, Tsubaki A. Temporal changes in cortical oxygenation in the motor-related areas and bilateral prefrontal cortex based on exercise intensity and respiratory metabolism during incremental exercise in male subjects: A near-Infrared spectroscopy study. Front Physiol 2022; 13:794473. [PMID: 36017334 PMCID: PMC9396126 DOI: 10.3389/fphys.2022.794473] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 07/07/2022] [Indexed: 11/13/2022] Open
Abstract
A recent study has reported that prefrontal cortex (PFC) activity during incremental exercise may be related to exercise termination on exhaustion. However, few studies have focused on motor-related areas during incremental exercise. This study investigated changes in the oxygenation of the PFC and motor-related areas using near-infrared spectroscopy during incremental exercise. Moreover, we analyzed the effect of exercise termination on changes in cortical oxygenation based on exercise intensity and respiratory metabolism. Sixteen healthy young male patients participated in this study. After a 4-min rest and 4-min warm-up period, incremental exercise was started at an incremental load corresponding to 20 W/min. Oxyhemoglobin (O2Hb), deoxyhemoglobin (HHb), and total hemoglobin (THb) in the bilateral PFC, supplementary motor area, and primary motor cortex were measured. We evaluated changes in oxygenation in each cortex before and after the anaerobic threshold (AT) and respiratory compensation point to identify changes due to respiratory metabolism. O2Hb and THb increased from moderate intensity or after AT to maximal exercise, and HHb increased slowly compared to O2Hb and THb; these changes in hemoglobin levels were consistent in all cortical areas we measured. However, the increase in each hemoglobin level in the bilateral PFC during incremental exercise was faster than that in motor-related areas. Moreover, changes in cortical oxygenation in the right PFC were faster than those in the left PFC. These results suggest changes based on differences in neural activity due to the cortical area.
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Affiliation(s)
- Sho Kojima
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
- Department of Physical Therapy, Kisen Hospital, Tokyo, Japan
| | | | - Kazuki Hotta
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Weixiang Qin
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
| | - Naoto Usui
- Department of Physical Therapy, Kisen Hospital, Tokyo, Japan
| | - Atsuhiro Tsubaki
- Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan
- *Correspondence: Atsuhiro Tsubaki,
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Gomez A, Sainbhi AS, Froese L, Batson C, Slack T, Stein KY, Cordingley DM, Mathieu F, Zeiler FA. The Quantitative Associations Between Near Infrared Spectroscopic Cerebrovascular Metrics and Cerebral Blood Flow: A Scoping Review of the Human and Animal Literature. Front Physiol 2022; 13:934731. [PMID: 35910568 PMCID: PMC9335366 DOI: 10.3389/fphys.2022.934731] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 06/09/2022] [Indexed: 11/13/2022] Open
Abstract
Cerebral blood flow (CBF) is an important physiologic parameter that is vital for proper cerebral function and recovery. Current widely accepted methods of measuring CBF are cumbersome, invasive, or have poor spatial or temporal resolution. Near infrared spectroscopy (NIRS) based measures of cerebrovascular physiology may provide a means of non-invasively, topographically, and continuously measuring CBF. We performed a systematically conducted scoping review of the available literature examining the quantitative relationship between NIRS-based cerebrovascular metrics and CBF. We found that continuous-wave NIRS (CW-NIRS) was the most examined modality with dynamic contrast enhanced NIRS (DCE-NIRS) being the next most common. Fewer studies assessed diffuse correlation spectroscopy (DCS) and frequency resolved NIRS (FR-NIRS). We did not find studies examining the relationship between time-resolved NIRS (TR-NIRS) based metrics and CBF. Studies were most frequently conducted in humans and animal studies mostly utilized large animal models. The identified studies almost exclusively used a Pearson correlation analysis. Much of the literature supported a positive linear relationship between changes in CW-NIRS based metrics, particularly regional cerebral oxygen saturation (rSO2), and changes in CBF. Linear relationships were also identified between other NIRS based modalities and CBF, however, further validation is needed.
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Affiliation(s)
- Alwyn Gomez
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
- Section of Neurosurgery, Department of Surgery, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
- *Correspondence: Alwyn Gomez,
| | - Amanjyot Singh Sainbhi
- Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada
| | - Logan Froese
- Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada
| | - Carleen Batson
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Trevor Slack
- Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada
| | - Kevin Y. Stein
- Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada
| | - Dean M. Cordingley
- Applied Health Sciences Program, University of Manitoba, Winnipeg, MB, Canada
- Pan Am Clinic Foundation, Winnipeg, MB, Canada
| | - Francois Mathieu
- Interdepartmental Division of Critical Care, Department of Medicine, University of Toronto, Toronto, ON, Canada
| | - Frederick A. Zeiler
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
- Section of Neurosurgery, Department of Surgery, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
- Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada
- Centre on Aging, University of Manitoba, Winnipeg, MB, Canada
- Division of Anaesthesia, Department of Medicine, Addenbrooke’s Hospital, University of Cambridge, Cambridge, MA, United Kingdom
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
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Dogra A, Ahuja CK, Kumar S. Image Integration Procedures in Multisensory Medical Images: A Comprehensive Survey of the state-of-the-art Paradigms. Curr Med Imaging 2021; 18:476-495. [PMID: 33687885 DOI: 10.2174/1573405617666210308112825] [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: 11/02/2020] [Revised: 01/13/2021] [Accepted: 01/21/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Obtaining the medical history from a patient is a tedious task for doctors as it depends on a lot of factors which are difficult to keep track from a patient's perspective. Doctors have to rely upon the technological tools to make a swift and accurate judgment about the patient's health. INTRODUCTION Out of many such tools, there are two special imaging modalities known as X-ray - Computed Tomography (CT) and Magnetic Resonance imaging (MRI) which are of a significant importance in the medical world assisting the diagnosis process. METHOD The advancement in signal processing theory and analysis has led to design and implementation of large number of image processing and fusion algorithms. Each of these methods have evolved in terms in their terms of their computational efficiency and visual results over the years. RESULT Various researches have revealed their properties in terms of their efficiency and outreach and it has been concluded that image fusion can be very suitable process that can help to compensate the drawbacks. CONCLUSION In this manuscript, recent state-of-the-art techniques have been used to fuse these image modalities and established its need and importance in a more intuitive way with the help of a wide range of assessment parameters.
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Affiliation(s)
- Ayush Dogra
- Central Scientific Instruments Organization, Chandigarh. India
| | - Chirag Kamal Ahuja
- Post Graduate Institute of Medical, Education & Research (PGIMER), Chandigarh. India
| | - Sanjeev Kumar
- Central Scientific Instruments Organization, Chandigarh. India
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7
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Rahman MA, Siddik AB, Ghosh TK, Khanam F, Ahmad M. A Narrative Review on Clinical Applications of fNIRS. J Digit Imaging 2020; 33:1167-1184. [PMID: 32989620 PMCID: PMC7573058 DOI: 10.1007/s10278-020-00387-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 08/06/2020] [Accepted: 09/14/2020] [Indexed: 01/08/2023] Open
Abstract
Functional near-infrared spectroscopy (fNIRS) is a relatively new imaging modality in the functional neuroimaging research arena. The fNIRS modality non-invasively investigates the change of blood oxygenation level in the human brain utilizing the transillumination technique. In the last two decades, the interest in this modality is gradually evolving for its real-time monitoring, relatively low-cost, radiation-less environment, portability, patient-friendliness, etc. Including brain-computer interface and functional neuroimaging research, this technique has some important application of clinical perspectives such as Alzheimer's disease, schizophrenia, dyslexia, Parkinson's disease, childhood disorders, post-neurosurgery dysfunction, attention, functional connectivity, and many more can be diagnosed as well as in some form of assistive modality in clinical approaches. Regarding the issue, this review article presents the current scopes of fNIRS in medical assistance, clinical decision making, and future perspectives. This article also covers a short history of fNIRS, fundamental theories, and significant outcomes reported by a number of scholarly articles. Since this review article is hopefully the first one that comprehensively explores the potential scopes of the fNIRS in a clinical perspective, we hope it will be helpful for the researchers, physicians, practitioners, current students of the functional neuroimaging field, and the related personnel for their further studies and applications.
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Affiliation(s)
- Md. Asadur Rahman
- Department of Biomedical Engineering, Military Institute of Science and Technology (MIST), Dhaka, 1216 Bangladesh
| | - Abu Bakar Siddik
- Department of Biomedical Engineering, Khulna University of Engineering & Technology (KUET), Khulna, 9203 Bangladesh
| | - Tarun Kanti Ghosh
- Department of Biomedical Engineering, Khulna University of Engineering & Technology (KUET), Khulna, 9203 Bangladesh
| | - Farzana Khanam
- Department of Biomedical Engineering, Jashore University of Science and Technology (JUST), Jashore, 7408 Bangladesh
| | - Mohiuddin Ahmad
- Department of Electrical and Electronic Engineering, Khulna University of Engineering & Technology (KUET), Khulna, 9203 Bangladesh
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8
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Makwana B, Tart-Zelvin A, Xu X, Gunstad JJ, Cote DM, Poppas A, Cohen RA, Sweet LH. Cerebrovascular Perfusion among Older Adults with and Without Cardiovascular Disease. J Neuroimaging 2020; 30:851-856. [PMID: 32648657 DOI: 10.1111/jon.12757] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/17/2020] [Accepted: 06/24/2020] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND AND PURPOSE Cardiovascular disease (CVD) encompasses a range of disorders that affect health and functioning in older adults. While cognitive declines have been linked to both cardiovascular and cerebral blood perfusion, protective neurovascular mechanisms raise the question whether cerebrovascular perfusion differs as a function of cardiovascular health status. The present study examined whether cerebrovascular perfusion significantly differs between healthy older adults with and without diagnosed CVD. The study also examined whether previously documented sex differences in cerebral perfusion would be replicated. METHODS Twenty CVD patients without significant heart failure and 39 healthy controls were recruited to undergo a comprehensive assessment, including an interview, echocardiogram, and magnetic resonance imaging). Arterial spin labeling was used to quantify cerebral blood perfusion. RESULTS Both groups exhibited mean left ventricular ejection fractions that fell within normal limits. In line with previous research, women exhibited significantly higher cerebral perfusion than men. There were no significant group differences in whole brain cerebrovascular perfusion, regional perfusion, or white matter perfusion by patient status after accounting for sex and age. CONCLUSIONS These findings suggest that the effects of mild CVD on cerebrovascular perfusion are minimal. Future studies are needed to investigate the mechanisms involved in maintaining cerebrovascular perfusion in the context of altered peripheral perfusion and to determine whether this finding extends to more acute or severe CVD.
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Affiliation(s)
- Bindal Makwana
- Department of Psychology, Idaho State University, Pocatello, ID
| | - Ariana Tart-Zelvin
- Department of Psychology, Idaho State University, Pocatello, ID.,Psychiatry Department, University of Michigan/Michigan Medicine, Ann Arbor, MI
| | - Xiaomeng Xu
- Department of Psychology, Idaho State University, Pocatello, ID
| | - John J Gunstad
- Department of Psychological Sciences, Kent State University, Kent, OH
| | | | - Athena Poppas
- The Miriam and Newport Hospitals, Cardiovascular Institute at Rhode Island, Providence, RI
| | - Ronald A Cohen
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL
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Al Harrach M, Rousseau F, Groeschel S, Chabrier S, Hertz-Pannier L, Lefevre J, Dinomais M. Is the Blood Oxygenation Level-Dependent fMRI Response to Motor Tasks Altered in Children After Neonatal Stroke? Front Hum Neurosci 2020; 14:154. [PMID: 32410976 PMCID: PMC7202247 DOI: 10.3389/fnhum.2020.00154] [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: 12/04/2019] [Accepted: 04/07/2020] [Indexed: 12/13/2022] Open
Abstract
Functional MRI is increasingly being used in the assessment of brain activation and connectivity following stroke. Many of these studies rely on the Blood Oxygenation Level Dependent (BOLD) contrast. However, the stability, as well as the accuracy of the BOLD response to motor task in the ipsilesional hemisphere, remains ambiguous. In this work, the BOLD signal acquired from both healthy and affected hemispheres was analyzed in 7-year-old children who sustained a Neonatal Arterial Ischemic Stroke (NAIS). Accordingly, a repetitive motor task of the contralesional and the ipsilesional hands was performed by 33 patients with unilateral lesions. These patients were divided into two groups: those without cerebral palsy (NAIS), and those with cerebral palsy (CP). The BOLD signal time course was obtained from distinctly defined regions of interest (ROIs) extracted from the functional activation maps of 30 healthy controls with similar age and demographic characteristics as the patients. An ROI covering both the primary motor cortex (M1) and the primary somatosensory cortex (S1) was also tested. Compared with controls, NAIS patients without CP had similar BOLD amplitude variation for both the contralesional and the ipsilesional hand movements. However, in the case of NAIS patients with CP, a significant difference in the averaged BOLD amplitude was found between the healthy and affected hemisphere. In both cases, no progressive attenuation of the BOLD signal amplitude was observed throughout the task epochs. Besides, results also showed a correlation between the BOLD signal percentage variation of the lesioned hemisphere and the dexterity level. These findings suggest that for patients who sustained a NAIS with no extensive permanent motor impairment, BOLD signal-based data analysis can be a valuable tool for the evaluation of functional brain networks.
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Affiliation(s)
- Mariam Al Harrach
- Laboratoire Angevin de Recherche en Ingénierie des Systèmes (LARIS) EA7315, Université d'Angers, Polytech Angers, Angers, France
| | | | - Samuel Groeschel
- Department of Child Neurology, Paediatric Neuroimaging, University Hospital, Tübingen, Germany
| | - Stéphane Chabrier
- INSERM UMR1059 Sainbiose, Univ Saint-Étienne, Univ Lyon, Saint-Étienne, France.,INSERM, CIC 1408, CHU Saint-Étienne, French Centre for Paediatric Stroke, Paediatric Physical and Rehabilitation Medicine Department, Saint-Étienne, France
| | - Lucie Hertz-Pannier
- INSERM U114 Neurospin, UNIACT, Institut Joliot, Université de Paris, CEA-Paris Saclay, Gif sur Yvette, France
| | - Julien Lefevre
- UMR CNRS 7289, Aix Marseille Université, Institut de Neurosciences de la Timone, Marseille, France
| | - Mickael Dinomais
- Laboratoire Angevin de Recherche en Ingénierie des Systèmes (LARIS) EA7315, Université d'Angers, Polytech Angers, Angers, France.,CHU Angers, Département de Médecine Physique et de Réadaptions and LUNAM, Angers, France
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LEE JOOHYUN, JUNG YOUNGJIN. FUNCTIONAL NEAR-INFRARED SPECTROSCOPY-BASED UPPER EXTREMITY FUNCTION REHABILITATION FOR STROKE SURVIVOR: A REVIEW. J MECH MED BIOL 2020. [DOI: 10.1142/s0219519420500013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Recently, the functional near-infrared spectroscopy (600–900[Formula: see text]nm electromagnetic wave) ([Formula: see text]-NIRS)-based rehabilitation researches have been studied for understanding the human brain. Although [Formula: see text]-NIRS can successfully measure the relative blood concentration changes of oxy-hemoglobin (HbO) and deoxy-hemoglobin (HbR) as an assessment tool to identify significant clinical intervention during pre- and post-rehabilitation therapy for stroke survivors, there is insufficient information particularly on the use of [Formula: see text]-NIRS as a clinical translation in upper extremity function rehabilitation. In order to widely utilize the [Formula: see text]-NIRS for upper extremity rehabilitation, device information, experiment design, measurement procedure, and analyzing method are described for clinician aspect in this study. In addition, further research trend was introduced from previous studies for stroke survivor rehabilitation. The authors believed that the information provided in this study can be a useful guideline to encourage future researchers to focus on upper extremity function rehabilitation of stroke survivors.
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Affiliation(s)
- JOO-HYUN LEE
- Department of Occupational Therapy, Baekseok University, Cheonan 31065, Republic of Korea
| | - YOUNG-JIN JUNG
- Department of Radiological Science, Dongseo University, Busan 47011, Republic of Korea
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11
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Comparison of Feature Vector Compositions to Enhance the Performance of NIRS-BCI-Triggered Robotic Hand Orthosis for Post-Stroke Motor Recovery. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9183845] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Recently, brain–computer interfaces, combined with feedback systems and goal-oriented training, have been investigated for their capacity to promote functional recovery after stroke. Accordingly, we developed a brain–computer interface-triggered robotic hand orthosis that assists hand-closing and hand-opening for post-stroke patients without sufficient motor output. In this system, near-infrared spectroscopy is used to monitor the affected motor cortex, and a linear discriminant analysis-based binary classifier estimates hand posture. The estimated posture then wirelessly triggers the robotic hand orthosis. For better performance of the brain–computer interface, we tested feature windows of different lengths and varying feature vector compositions with motor execution data from seven neurologically intact participants. The interaction between a feature window and a delay in the hemodynamic response significantly affected both classification accuracy (Matthew Correlation Coefficient) and detection latency. The ‘preserving channels’ feature vector was able to increase accuracy by 13.14% and decrease latency by 29.48%, relative to averaging. Oxyhemoglobin combined with deoxyhemoglobin improved accuracy by 3.71% and decreased latency by 6.01% relative to oxyhemoglobin alone. Thus, the best classification performance resulted in an accuracy of 0.7154 and a latency of 2.8515 s. The hand rehabilitation system was successfully implemented using this feature vector composition, which yielded better classification performance.
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12
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Guggisberg AG, Koch PJ, Hummel FC, Buetefisch CM. Brain networks and their relevance for stroke rehabilitation. Clin Neurophysiol 2019; 130:1098-1124. [PMID: 31082786 DOI: 10.1016/j.clinph.2019.04.004] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 03/04/2019] [Accepted: 04/08/2019] [Indexed: 12/21/2022]
Abstract
Stroke has long been regarded as focal disease with circumscribed damage leading to neurological deficits. However, advances in methods for assessing the human brain and in statistics have enabled new tools for the examination of the consequences of stroke on brain structure and function. Thereby, it has become evident that stroke has impact on the entire brain and its network properties and can therefore be considered as a network disease. The present review first gives an overview of current methodological opportunities and pitfalls for assessing stroke-induced changes and reorganization in the human brain. We then summarize principles of plasticity after stroke that have emerged from the assessment of networks. Thereby, it is shown that neurological deficits do not only arise from focal tissue damage but also from local and remote changes in white-matter tracts and in neural interactions among wide-spread networks. Similarly, plasticity and clinical improvements are associated with specific compensatory structural and functional patterns of neural network interactions. Innovative treatment approaches have started to target such network patterns to enhance recovery. Network assessments to predict treatment response and to individualize rehabilitation is a promising way to enhance specific treatment effects and overall outcome after stroke.
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Affiliation(s)
- Adrian G Guggisberg
- Division of Neurorehabilitation, Department of Clinical Neurosciences, University Hospital Geneva, Switzerland.
| | - Philipp J Koch
- Defitech Chair of Clinical Neuroengineering, Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), Swiss Federal Institute of Technology (EPFL), 1202 Geneva, Switzerland; Defitech Chair of Clinical Neuroengineering, Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), Swiss Federal Institute of Technology Valais (EPFL Valais), Clinique Romande de Réadaptation, 1951 Sion, Switzerland
| | - Friedhelm C Hummel
- Defitech Chair of Clinical Neuroengineering, Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), Swiss Federal Institute of Technology (EPFL), 1202 Geneva, Switzerland; Defitech Chair of Clinical Neuroengineering, Center for Neuroprosthetics (CNP) and Brain Mind Institute (BMI), Swiss Federal Institute of Technology Valais (EPFL Valais), Clinique Romande de Réadaptation, 1951 Sion, Switzerland; Department of Clinical Neuroscience, University Hospital Geneva, 1202 Geneva, Switzerland
| | - Cathrin M Buetefisch
- Depts of Neurology, Rehabilitation Medicine, Radiology, Emory University, Atlanta, GA, USA
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13
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Jeong E, Ryu H, Shin JH, Kwon GH, Jo G, Lee JY. High Oxygen Exchange to Music Indicates Auditory Distractibility in Acquired Brain Injury: An fNIRS Study with a Vector-Based Phase Analysis. Sci Rep 2018; 8:16737. [PMID: 30425287 PMCID: PMC6233191 DOI: 10.1038/s41598-018-35172-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 10/31/2018] [Indexed: 01/30/2023] Open
Abstract
Attention deficits due to auditory distractibility are pervasive among patients with acquired brain injury (ABI). It remains unclear, however, whether attention deficits following ABI specific to auditory modality are associated with altered haemodynamic responses. Here, we examined cerebral haemodynamic changes using functional near-infrared spectroscopy combined with a topological vector-based analysis method. A total of thirty-seven participants (22 healthy adults, 15 patients with ABI) performed a melodic contour identification task (CIT) that simulates auditory distractibility. Findings demonstrated that the melodic CIT was able to detect auditory distractibility in patients with ABI. The rate-corrected score showed that the ABI group performed significantly worse than the non-ABI group in both CIT1 (target contour identification against environmental sounds) and CIT2 (target contour identification against target-like distraction). Phase-associated response intensity during the CITs was greater in the ABI group than in the non-ABI group. Moreover, there existed a significant interaction effect in the left dorsolateral prefrontal cortex (DLPFC) during CIT1 and CIT2. These findings indicated that stronger hemodynamic responses involving oxygen exchange in the left DLPFC can serve as a biomarker for evaluating and monitoring auditory distractibility, which could potentially lead to the discovery of the underlying mechanism that causes auditory attention deficits in patients with ABI.
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Affiliation(s)
- Eunju Jeong
- Department of Arts and Technology, Hanyang University, Seoul, 04763, Republic of Korea.
- Division of Industrial Information Studies, Hanyang University, Seoul, 04763, Republic of Korea.
| | - Hokyoung Ryu
- Department of Arts and Technology, Hanyang University, Seoul, 04763, Republic of Korea
- Graduate School of Technology and Innovation Management, Hanyang University, Seoul, 04763, Republic of Korea
| | - Joon-Ho Shin
- Department of Neurorehabilitation, National Rehabilitation Center, Ministry of Health and Welfare, Seoul, 01022, Republic of Korea
| | - Gyu Hyun Kwon
- Department of Arts and Technology, Hanyang University, Seoul, 04763, Republic of Korea
- Graduate School of Technology and Innovation Management, Hanyang University, Seoul, 04763, Republic of Korea
| | - Geonsang Jo
- Department of Arts and Technology, Hanyang University, Seoul, 04763, Republic of Korea
| | - Ji-Yeong Lee
- Department of Neurorehabilitation, National Rehabilitation Center, Ministry of Health and Welfare, Seoul, 01022, Republic of Korea
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14
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Lee J, Yamate C, Taira M, Shinoda M, Urata K, Maruno M, Ito R, Saito H, Gionhaku N, Iinuma T, Iwata K. Prefrontal cortex activity during swallowing in dysphagia patients. J Oral Sci 2018; 60:329-335. [PMID: 29794397 DOI: 10.2334/josnusd.17-0238] [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] [Indexed: 11/01/2022]
Abstract
Prefrontal cortex activity is modulated by flavor and taste stimuli and changes during swallowing. We hypothesized that changes in the modulation of prefrontal cortex activity by flavor and taste were associated with swallowing movement and evaluated brain activity during swallowing in patients with dysphagia. To evaluate prefrontal cortex activity in dysphagia patients during swallowing, change in oxidized hemoglobin (z-score) was measured with near-infrared spectroscopy while dysphagia patients and healthy controls swallowed sweetened/unsweetened and flavored/unflavored jelly. Total z-scores were positive during swallowing of flavored/unsweetened jelly and negative during swallowing of unflavored/sweetened jelly in controls but negative during swallowing of sweetened/unsweetened and flavored/unflavored jelly in dysphagia patients. These findings suggest that taste and flavor during food swallowing are associated with positive and negative z-scores, respectively. Change in negative and positive z-scores may be useful in evaluating brain activity of dysphagia patients during swallowing of sweetened and unsweetened food.
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Affiliation(s)
- Jun Lee
- Department of Complete Denture Prosthodontics, Nihon University School of Dentistry
| | - Chisato Yamate
- Department of Cognitive Neurobiology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University.,Center for Brain Integration Research, Tokyo Medical and Dental University
| | - Masato Taira
- Department of Cognitive Neurobiology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University.,Center for Brain Integration Research, Tokyo Medical and Dental University
| | - Masamichi Shinoda
- Department of Physiology, Nihon University School of Dentistry.,Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry
| | - Kentaro Urata
- Department of Complete Denture Prosthodontics, Nihon University School of Dentistry
| | - Mitsuru Maruno
- Department of Complete Denture Prosthodontics, Nihon University School of Dentistry
| | - Reio Ito
- Department of Complete Denture Prosthodontics, Nihon University School of Dentistry
| | - Hiroto Saito
- Department of Complete Denture Prosthodontics, Nihon University School of Dentistry
| | - Nobuhito Gionhaku
- Department of Complete Denture Prosthodontics, Nihon University School of Dentistry
| | - Toshimitsu Iinuma
- Department of Complete Denture Prosthodontics, Nihon University School of Dentistry
| | - Koichi Iwata
- Department of Physiology, Nihon University School of Dentistry.,Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry
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15
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Lo CC, Lin PY, Hoe ZY, Chen JJJ. Near Infrared Spectroscopy Study of Cortical Excitability During Electrical Stimulation-Assisted Cycling for Neurorehabilitation of Stroke Patients. IEEE Trans Neural Syst Rehabil Eng 2018; 26:1292-1300. [PMID: 29877854 DOI: 10.1109/tnsre.2018.2829804] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In addition to generating functional limb movement via electrical stimulation, other research proposed lower intensity stimulation for stroke patients from proprioceptive and neuro-biofeedback aspects. This paper investigates the effects of different intensity levels of electrical stimulation during passive cycling on cortical activation using multichannel near infrared spectroscopy (NIRS) covering premotor cortex, supplementary motor area, sensorimotor cortex (SMC), and secondary sensory cortex (S2) regions. Sixteen subjects, including nine stroke patients and seven normal subjects, were instructed to perform passive cycling driven by an ergometer at a pace of 50 rpm under conditions without electrical stimulation (NES) and with low-intensity electrical stimulation (LES) at 10 mA and high-intensity electrical stimulation (HES) at 30 mA. Changes in oxyhemoglobin in different brain regions and the derived interhemispheric correlation coefficient (IHCC) representing the symmetry in response of two hemispheres were evaluated to observe cortical activation and cerebral autoregulation. Our results showed that cortical activation of normal subjects exhibited overall deactivations in HES compared with that under LES and NES. In stroke patients, bilateral S2 activated significantly greater under LES compared with those under NES and HES. The IHCC of the normal group displayed a significant higher value in SMC compared with that of the stroke group. This paper utilized noninvasive NIRS to observe hemodynamic changes and bilateral autoregulation symmetry from IHCC suggesting that passive cycling with LES could better facilitate cortical activation compared with that obtained with NES or HES. The results of this paper could provide general guidelines to simplify the settings of electrical stimulation-assisted-passive cycling in clinical use.
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16
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Para AE, Sam K, Poublanc J, Fisher JA, Crawley AP, Mikulis DJ. Invalidation of fMRI experiments secondary to neurovascular uncoupling in patients with cerebrovascular disease. J Magn Reson Imaging 2017; 46:1448-1455. [PMID: 28152241 DOI: 10.1002/jmri.25639] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 01/03/2017] [Indexed: 12/29/2022] Open
Abstract
PURPOSE Blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) is a technique used to infer neuronal activity from the observed changes in blood flow. Cerebrovascular reactivity (CVR) is the ability of arterioles to increase blood flow in response to vasodilatory stimulus. We hypothesize that in areas of disease where there is exhausted vascular reserve and impaired CVR there will be diminished blood flow response following neuronal activation, and that these areas would appear as false-negative tests on BOLD fMRI. MATERIALS AND METHODS Patients with steno-occlusive disease and unilateral hemodynamic impairment received a standardized hypercapnic stimuli while being imaged with BOLD fMRI to generate CVR maps. These were compared to traditional BOLD fMRI maps of neuronal activation in the motor cortex in response to a motor task. RESULTS Neuronal activation from the motor task was found to be linearly correlated with CVR (n = 11 patients, R = 0.82). Regions with positive (normal) CVR showed positive activation on BOLD fMRI, while regions with negative CVR had attenuated neuronal activation on BOLD fMRI. CONCLUSION In areas with cerebrovascular disease where CVR is impaired, there is uncoupling of neuronal activation and blood flow that confounds traditional BOLD fMRI. CVR mapping is a noninvasive MRI-based imaging technique that can provide information about the vascular reactivity of the brain that is important to consider when interpreting traditional BOLD fMRI studies. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2017;46:1448-1455.
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Affiliation(s)
- Andrea E Para
- Department of Medical Imaging, University of Western Ontario, London, Canada.,Division of Neuroradiology, Joint Department of Medical Imaging, University Health Network, Toronto, Canada
| | - Kevin Sam
- Division of Neuroradiology, Joint Department of Medical Imaging, University Health Network, Toronto, Canada
| | - Julien Poublanc
- Division of Neuroradiology, Joint Department of Medical Imaging, University Health Network, Toronto, Canada
| | - Joseph A Fisher
- Department of Anesthesiology, University Health Network and University of Toronto, Toronto, Canada
| | - Adrian P Crawley
- Division of Neuroradiology, Joint Department of Medical Imaging, University Health Network, Toronto, Canada.,Department of Medical Imaging, University of Toronto, Toronto, Canada
| | - David J Mikulis
- Division of Neuroradiology, Joint Department of Medical Imaging, University Health Network, Toronto, Canada.,Department of Medical Imaging, University of Toronto, Toronto, Canada
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17
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Tamilia E, Madsen JR, Grant PE, Pearl PL, Papadelis C. Current and Emerging Potential of Magnetoencephalography in the Detection and Localization of High-Frequency Oscillations in Epilepsy. Front Neurol 2017; 8:14. [PMID: 28194133 PMCID: PMC5276819 DOI: 10.3389/fneur.2017.00014] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 01/11/2017] [Indexed: 01/19/2023] Open
Abstract
Up to one-third of patients with epilepsy are medically intractable and need resective surgery. To be successful, epilepsy surgery requires a comprehensive preoperative evaluation to define the epileptogenic zone (EZ), the brain area that should be resected to achieve seizure freedom. Due to lack of tools and methods that measure the EZ directly, this area is defined indirectly based on concordant data from a multitude of presurgical non-invasive tests and intracranial recordings. However, the results of these tests are often insufficiently concordant or inconclusive. Thus, the presurgical evaluation of surgical candidates is frequently challenging or unsuccessful. To improve the efficacy of the surgical treatment, there is an overriding need for reliable biomarkers that can delineate the EZ. High-frequency oscillations (HFOs) have emerged over the last decade as new potential biomarkers for the delineation of the EZ. Multiple studies have shown that HFOs are spatially associated with the EZ. Despite the encouraging findings, there are still significant challenges for the translation of HFOs as epileptogenic biomarkers to the clinical practice. One of the major barriers is the difficulty to detect and localize them with non-invasive techniques, such as magnetoencephalography (MEG) or scalp electroencephalography (EEG). Although most literature has studied HFOs using invasive recordings, recent studies have reported the detection and localization of HFOs using MEG or scalp EEG. MEG seems to be particularly advantageous compared to scalp EEG due to its inherent advantages of being less affected by skull conductivity and less susceptible to contamination from muscular activity. The detection and localization of HFOs with MEG would largely expand the clinical utility of these new promising biomarkers to an earlier stage in the diagnostic process and to a wider range of patients with epilepsy. Here, we conduct a thorough critical review of the recent MEG literature that investigates HFOs in patients with epilepsy, summarizing the different methodological approaches and the main findings. Our goal is to highlight the emerging potential of MEG in the non-invasive detection and localization of HFOs for the presurgical evaluation of patients with medically refractory epilepsy (MRE).
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Affiliation(s)
- Eleonora Tamilia
- Fetal-Neonatal Neuroimaging and Developmental Science Center, Division of Newborn Medicine, Department of Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Joseph R. Madsen
- Division of Epilepsy Surgery, Department of Neurosurgery, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Patricia Ellen Grant
- Fetal-Neonatal Neuroimaging and Developmental Science Center, Division of Newborn Medicine, Department of Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Phillip L. Pearl
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
| | - Christos Papadelis
- Fetal-Neonatal Neuroimaging and Developmental Science Center, Division of Newborn Medicine, Department of Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
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18
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Hypercapnic evaluation of vascular reactivity in healthy aging and acute stroke via functional MRI. NEUROIMAGE-CLINICAL 2016; 12:173-9. [PMID: 27437178 PMCID: PMC4939388 DOI: 10.1016/j.nicl.2016.06.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/26/2016] [Accepted: 06/22/2016] [Indexed: 11/23/2022]
Abstract
Functional MRI (fMRI) is well-established for the study of brain function in healthy populations, although its clinical application has proven more challenging. Specifically, cerebrovascular reactivity (CVR), which allows the assessment of the vascular response that serves as the basis for fMRI, has been shown to be reduced in healthy aging as well as in a range of diseases, including chronic stroke. However, the timing of when this occurs relative to the stroke event is unclear. We used a breath-hold fMRI task to evaluate CVR across gray matter in a group of acute stroke patients (< 10 days from stroke; N = 22) to address this question. These estimates were compared with those from both age-matched (N = 22) and younger (N = 22) healthy controls. As expected, young controls had the greatest mean CVR, as indicated by magnitude and extent of fMRI activation; however, stroke patients did not differ from age-matched controls. Moreover, the ipsilesional and contralesional hemispheres of stroke patients did not differ with respect to any of these measures. These findings suggest that fMRI remains a valid tool within the first few days of a stroke, particularly for group fMRI studies in which findings are compared with healthy subjects of similar age. However, given the relatively high variability in CVR observed in our stroke sample, caution is warranted when interpreting fMRI data from individual patients or a small cohort. We conclude that a breath-hold task can be a useful addition to functional imaging protocols for stroke patients. Breath-holding can be used to assess the validity of fMRI in stroke patients. Vascular reactivity, estimated by breath-hold fMRI, was greatest in young controls. Acute stroke patients and age-matched controls had similar vascular reactivity. Modeling the breath-hold response on an individual basis can improve results.
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19
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Carey LM, Seitz RJ. Functional Neuroimaging in Stroke Recovery and Neurorehabilitation: Conceptual Issues and Perspectives. Int J Stroke 2016; 2:245-64. [DOI: 10.1111/j.1747-4949.2007.00164.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Background In stroke, functional neuroimaging has become a potent diagnostic tool; opened new insights into the pathophysiology of ischaemic damage in the human brain; and made possible the assessment of functional–structural relationships in postlesion recovery. Summary of review Here, we give a critical account on the potential and limitation of functional neuroimaging and discuss concepts related to the use of neuroimaging for exploring the neurobiological and neuroanatomical mechanisms of poststroke recovery and neurorehabilitation. We identify and provide evidence for five hypotheses that functional neuroimaging can provide new insights into: adaptation occurs at the level of functional brain systems; the brain–behaviour relationship varies with recovery and over time; functional neuroimaging can improve our ability to predict recovery and select individuals for rehabilitation; mechanisms of recovery reflect different pathophysiological phases; and brain adaptation may be modulated by experience and specific rehabilitation. The significance and application of this new evidence is discussed, and recommendations made for investigations in the field. Conclusion Functional neuroimaging is an important tool to explore the mechanisms underlying brain plasticity and, thereby, to guide clinical research in neurorehabilitation.
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Affiliation(s)
- Leeanne M. Carey
- National Stroke Research Institute, Neurosciences Building, Heidelberg Heights, Vic., Australia
- School of Occupational Therapy, LaTrobe University, Bundoora, Vic., Australia
| | - Rüdiger J. Seitz
- National Stroke Research Institute, Neurosciences Building, Heidelberg Heights, Vic., Australia
- Institute of Advanced Study, La Trobe University, Bundoora, Vic., Australia
- Department of Neurology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
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20
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Interpreting Intervention Induced Neuroplasticity with fMRI: The Case for Multimodal Imaging Strategies. Neural Plast 2015; 2016:2643491. [PMID: 26839711 PMCID: PMC4709757 DOI: 10.1155/2016/2643491] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 09/27/2015] [Indexed: 12/03/2022] Open
Abstract
Direct measurement of recovery from brain injury is an important goal in neurorehabilitation, and requires reliable, objective, and interpretable measures of changes in brain function, referred to generally as “neuroplasticity.” One popular imaging modality for measuring neuroplasticity is task-based functional magnetic resonance imaging (t-fMRI). In the field of neurorehabilitation, however, assessing neuroplasticity using t-fMRI presents a significant challenge. This commentary reviews t-fMRI changes commonly reported in patients with cerebral palsy or acquired brain injuries, with a focus on studies of motor rehabilitation, and discusses complexities surrounding their interpretations. Specifically, we discuss the difficulties in interpreting t-fMRI changes in terms of their underlying causes, that is, differentiating whether they reflect genuine reorganisation, neurological restoration, compensation, use of preexisting redundancies, changes in strategy, or maladaptive processes. Furthermore, we discuss the impact of heterogeneous disease states and essential t-fMRI processing steps on the interpretability of activation patterns. To better understand therapy-induced neuroplastic changes, we suggest that researchers utilising t-fMRI consider concurrently acquiring information from an additional modality, to quantify, for example, haemodynamic differences or microstructural changes. We outline a variety of such supplementary measures for investigating brain reorganisation and discuss situations in which they may prove beneficial to the interpretation of t-fMRI data.
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21
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Yassi N, Malpas CB, Campbell BC, Moffat B, Steward C, Parsons MW, Desmond PM, Donnan GA, Davis SM, Bivard A. Contralesional Thalamic Surface Atrophy and Functional Disconnection 3 Months after Ischemic Stroke. Cerebrovasc Dis 2015; 39:232-41. [DOI: 10.1159/000381105] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 02/18/2015] [Indexed: 11/19/2022] Open
Abstract
Background: Remote structural and functional changes have been previously described after stroke and may have an impact on clinical outcome. We aimed to use multimodal MRI to investigate contralesional subcortical structural and functional changes 3 months after anterior circulation ischemic stroke. Methods: Fifteen patients with acute ischemic stroke had multimodal MRI imaging (including high resolution structural T1-MPRAGE and resting state fMRI) within 1 week of onset and at 1 and 3 months. Seven healthy controls of similar age group were also imaged at a single time point. Contralesional subcortical structural volume was assessed using an automated segmentation algorithm in FMRIB's Integrated Registration and Segmentation Tool (FIRST). Functional connectivity changes were assessed using the intrinsic connectivity contrast (ICC), which was calculated using the functional connectivity toolbox for correlated and anticorrelated networks (Conn). Results: Contralesional thalamic volume in the stroke patients was significantly reduced at 3 months compared to baseline (median change -2.1%, interquartile range [IQR] -3.4-0.4, p = 0.047), with the predominant areas demonstrating atrophy geometrically appearing to be the superior and inferior surface. The difference in volume between the contralesional thalamus at baseline (mean 6.41 ml, standard deviation [SD] 0.6 ml) and the mean volume of the 2 thalami in controls (mean 7.22 ml, SD 1.1 ml) was not statistically significant. The degree of longitudinal thalamic atrophy in patients was correlated with baseline stroke severity with more severe strokes being associated with a greater degree of atrophy (Spearman's rho -0.54, p = 0.037). There was no significant difference between baseline contralesional thalamic ICC in patients and control thalamic ICC. However, in patients, there was a significant linear reduction in the mean ICC of the contralesional thalamus over the imaging time points (p = 0.041), indicating reduced connectivity to the remainder of the brain. Conclusions: These findings highlight the importance of remote brain areas, such as the contralesional thalamus, in stroke recovery. Similar methods have the potential to be used in the prediction of stroke outcome or as imaging biomarkers of stroke recovery.
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22
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Veldsman M, Cumming T, Brodtmann A. Beyond BOLD: optimizing functional imaging in stroke populations. Hum Brain Mapp 2014; 36:1620-36. [PMID: 25469481 DOI: 10.1002/hbm.22711] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 11/14/2014] [Accepted: 11/25/2014] [Indexed: 12/11/2022] Open
Abstract
Blood oxygenation level-dependent (BOLD) signal changes are often assumed to directly reflect neural activity changes. Yet the real relationship is indirect, reliant on numerous assumptions, and subject to several sources of noise. Deviations from the core assumptions of BOLD contrast functional magnetic resonance imaging (fMRI), and their implications, have been well characterized in healthy populations, but are frequently neglected in stroke populations. In addition to conspicuous local structural and vascular changes after stroke, there are many less obvious challenges in the imaging of stroke populations. Perilesional ischemic changes, remodeling in regions distant to lesion sites, and diffuse perfusion changes all complicate interpretation of BOLD signal changes in standard fMRI protocols. Most stroke patients are also older than the young populations on which assumptions of neurovascular coupling and the typical analysis pipelines are based. We present a review of the evidence to show that the basic assumption of neurovascular coupling on which BOLD-fMRI relies does not capture the complex changes arising from stroke, both pathological and recovery related. As a result, estimating neural activity using the canonical hemodynamic response function is inappropriate in a number of contexts. We review methods designed to better estimate neural activity in stroke populations. One promising alternative to event-related fMRI is a resting-state-derived functional connectivity approach. Resting-state fMRI is well suited to stroke populations because it makes no performance demands on patients and is capable of revealing network-based pathology beyond the lesion site.
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Affiliation(s)
- Michele Veldsman
- The Florey Institute for Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
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23
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Siero JCW, Hartkamp NS, Donahue MJ, Harteveld AA, Compter A, Petersen ET, Hendrikse J. Neuronal activation induced BOLD and CBF responses upon acetazolamide administration in patients with steno-occlusive artery disease. Neuroimage 2014; 105:276-85. [PMID: 25261002 DOI: 10.1016/j.neuroimage.2014.09.033] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 09/12/2014] [Accepted: 09/16/2014] [Indexed: 12/26/2022] Open
Abstract
Blood-oxygenation-level-dependent (BOLD) MRI is widely used for inferring neuronal activation and is becoming increasingly popular for assessing cerebrovascular reactivity (CVR) when combined with a vasoactive stimulus. The BOLD signal contains changes in cerebral blood flow (CBF) and thus information regarding neurovascular coupling and CVR. The BOLD signal, however, is also modulated by changes in cerebral blood volume (CBV) and cerebral metabolic rate of oxygen (CMRO2), as well as changes in the physiological baseline state. Here, we measured BOLD and CBF responses upon neuronal (visual) activation, before and after a vasodilatory challenge (acetazolamide, ACZ) in patients with vertebrobasilar steno-occlusive disease. After ACZ, the neuronal activation induced BOLD response was reduced or even negative (3 out of 8 subjects), whereas the CBF response remained similar. We show that BOLD alone cannot correctly assess the neuronal activation and underlying neurovascular coupling. The generally assumed positive relationship between BOLD and CBF responses may be severely compromised under changes in the physiological baseline state. Accompanying CBF measurements contain crucial information, and simulations suggest an altered flow-metabolism coupling in these patients.
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Affiliation(s)
- Jeroen C W Siero
- Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
| | - Nolan S Hartkamp
- Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Manus J Donahue
- Radiology and Radiological Sciences, Vanderbilt University School of Medicine, Nashville, TN, USA; Physics and Astronomy, Vanderbilt University School of Medicine, Nashville, TN, USA; Neurology, Vanderbilt University School of Medicine, Nashville, TN, USA; Psychiatry, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Anita A Harteveld
- Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Annette Compter
- Department of Neurology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Esben T Petersen
- Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Jeroen Hendrikse
- Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
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24
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Li W, Li Y, Zhu W, Chen X. Changes in brain functional network connectivity after stroke. Neural Regen Res 2014; 9:51-60. [PMID: 25206743 PMCID: PMC4146323 DOI: 10.4103/1673-5374.125330] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/16/2013] [Indexed: 01/15/2023] Open
Abstract
Studies have shown that functional network connection models can be used to study brain network changes in patients with schizophrenia. In this study, we inferred that these models could also be used to explore functional network connectivity changes in stroke patients. We used independent component analysis to find the motor areas of stroke patients, which is a novel way to determine these areas. In this study, we collected functional magnetic resonance imaging datasets from healthy controls and right-handed stroke patients following their first ever stroke. Using independent component analysis, six spatially independent components highly correlated to the experimental paradigm were extracted. Then, the functional network connectivity of both patients and controls was established to observe the differences between them. The results showed that there were 11 connections in the model in the stroke patients, while there were only four connections in the healthy controls. Further analysis found that some damaged connections may be compensated for by new indirect connections or circuits produced after stroke. These connections may have a direct correlation with the degree of stroke rehabilitation. Our findings suggest that functional network connectivity in stroke patients is more complex than that in hea-lthy controls, and that there is a compensation loop in the functional network following stroke. This implies that functional network reorganization plays a very important role in the process of rehabilitation after stroke.
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Affiliation(s)
- Wei Li
- Key Laboratory of Image Processing and Intelligent Control, Ministry of Education, Wuhan, Hubei Province, China ; Department of Control Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Yapeng Li
- Key Laboratory of Image Processing and Intelligent Control, Ministry of Education, Wuhan, Hubei Province, China ; Department of Control Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Wenzhen Zhu
- Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Xi Chen
- Key Laboratory of Image Processing and Intelligent Control, Ministry of Education, Wuhan, Hubei Province, China ; Department of Control Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
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25
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Physiological mechanism of increase in deoxy-hemoglobin concentration during neuronal activation in patients with cerebral ischemia: a simulation study with the balloon model. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014. [PMID: 24729237 DOI: 10.1007/978-1-4939-0620-8_30] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Patients with cerebral ischemia or brain tumor have been reported to exhibit an increase of deoxygenated hemoglobin (deoxy-Hb) together with an increase of oxygenated hemoglobin (oxy-Hb). However, the physiological mechanisms underlying this hemodynamic response pattern are unclear. In this study, we performed a simulation using the balloon model (Buxton et al., Magn Reson Med 39:855-864, 1998). We hypothesized that the oxygen extraction rate during the rest period (E 0) in the patients is larger than in normal subjects, because the cerebral blood flow and the speed at which the blood passes through the brain tissues are lower in the patients. The simulation result showed an increase of deoxy-Hb as well as oxy-Hb, especially when E 0 is extremely high. Thus, the results of our simulation suggest that the increase of deoxy-Hb during activation in patients with ischemia or brain tumor is caused by an increased oxygen extraction rate at rest, compared with that of healthy adults.
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Tanida1 M, Sakatani K, Tsujii T. Relation between working memory performance and evoked cerebral blood oxygenation changes in the prefrontal cortex evaluated by quantitative time-resolved near-infrared spectroscopy. Neurol Res 2013; 34:114-9. [DOI: 10.1179/1743132811y.0000000066] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Affiliation(s)
| | - Kaoru Sakatani
- Department of Neurological SurgeryDivision of Optical Brain Engineering, Nihon University School of Medicine, Tokyo, Japan
| | - Takeo Tsujii
- Department of Neurological SurgeryDivision of Optical Brain Engineering, Nihon University School of Medicine, Tokyo, Japan
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de Haan B, Rorden C, Karnath HO. Abnormal perilesional BOLD signal is not correlated with stroke patients' behavior. Front Hum Neurosci 2013; 7:669. [PMID: 24137123 PMCID: PMC3797400 DOI: 10.3389/fnhum.2013.00669] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 09/25/2013] [Indexed: 11/13/2022] Open
Abstract
Several functional magnetic resonance imaging (fMRI) studies of acute stroke have reported that patients with behavioral deficits show abnormal signal in intact regions of the damaged hemisphere close to the lesion border relative to homologous regions of the patient's intact hemisphere (causing an interhemispheric imbalance) as well as analogous regions in healthy controls. These effects have been interpreted as demonstrating a causal relationship between the abnormal fMRI signal and the pathological behavior. Here we explore an alternative explanation: perhaps the abnormal Blood-Oxygenation Level Dependent (BOLD) fMRI signal is merely a function of distance from the acute lesion. To investigate this hypothesis, we examined three patients with an acute right hemisphere cortical stroke who did not show any overt behavioral deficits, as well as nine healthy elderly controls. We acquired fMRI data while the participants performed a simple visual orientation judgment task. In patients, we observed an abnormal interhemispheric balance consisting of lower levels of percent signal change in perilesional areas of the damaged hemisphere relative to homologous areas in neurologically healthy controls. This suggests that the physiological changes and corresponding interhemispheric imbalance detected by fMRI BOLD in acute stroke observed close to the lesion border may not necessarily reflect changes in the neural function, nor necessarily influence the individuals' (e.g., attentional) behavior.
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Affiliation(s)
- Bianca de Haan
- Center of Neurology, Division of Neuropsychology, Hertie-Institute of Clinical Brain Research, University of TübingenTübingen, Germany
| | - Chris Rorden
- Department of Psychology, University of South CarolinaColumbia, SC, USA
| | - Hans-Otto Karnath
- Center of Neurology, Division of Neuropsychology, Hertie-Institute of Clinical Brain Research, University of TübingenTübingen, Germany
- Department of Psychology, University of South CarolinaColumbia, SC, USA
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Hu XL, Tong KY, Wei XJ, Rong W, Susanto EA, Ho SK. The effects of post-stroke upper-limb training with an electromyography (EMG)-driven hand robot. J Electromyogr Kinesiol 2013; 23:1065-74. [PMID: 23932795 DOI: 10.1016/j.jelekin.2013.07.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 07/05/2013] [Accepted: 07/13/2013] [Indexed: 01/10/2023] Open
Abstract
Loss of hand function and finger dexterity are main disabilities in the upper limb after stroke. An electromyography (EMG)-driven hand robot had been developed for post-stroke rehabilitation training. The effectiveness of the hand robot assisted whole upper limb training was investigated on persons with chronic stroke (n=10) in this work. All subjects attended a 20-session training (3-5times/week) by using the hand robot to practice object grasp/release and arm transportation tasks. Significant motor improvements were observed in the Fugl-Meyer hand/wrist and shoulder/elbow scores (p<0.05), and also in the Action Research Arm Test and Wolf Motor Function Test (p<0.05). Significant reduction in spasticity of the fingers as was measured by the Modified Ashworth Score (p<0.05). The training improved the muscle co-ordination between the antagonist muscle pair (flexor digitorum (FD) and extensor digitorum (ED)), associated with a significant reduction in the ED EMG level (p<0.05) and a significant decrease of ED and FD co-contraction during the training (p<0.05); the excessive muscle activities in the biceps brachii were also reduced significantly after the training (p<0.05).
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Affiliation(s)
- X L Hu
- Interdisciplinary Division of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong
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Meinzer M, Beeson PM, Cappa S, Crinion J, Kiran S, Saur D, Parrish T, Crosson B, Thompson CK. Neuroimaging in aphasia treatment research: consensus and practical guidelines for data analysis. Neuroimage 2013; 73:215-24. [PMID: 22387474 PMCID: PMC3416913 DOI: 10.1016/j.neuroimage.2012.02.058] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 02/19/2012] [Indexed: 11/19/2022] Open
Abstract
Functional magnetic resonance imaging is the most widely used imaging technique to study treatment-induced recovery in post-stroke aphasia. The longitudinal design of such studies adds to the challenges researchers face when studying patient populations with brain damage in cross-sectional settings. The present review focuses on issues specifically relevant to neuroimaging data analysis in aphasia treatment research identified in discussions among international researchers at the Neuroimaging in Aphasia Treatment Research Workshop held at Northwestern University (Evanston, Illinois, USA). In particular, we aim to provide the reader with a critical review of unique problems related to the pre-processing, statistical modeling and interpretation of such data sets. Despite the fact that data analysis procedures critically depend on specific design features of a given study, we aim to discuss and communicate a basic set of practical guidelines that should be applicable to a wide range of studies and useful as a reference for researchers pursuing this line of research.
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Affiliation(s)
- Marcus Meinzer
- Charite Universitätsmedizin, Department of Neurology, Center for Stroke Research Berlin & Cluster of Excellence NeuroCure, Berlin, Germany.
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Promjunyakul NO, Schmit BD, Schindler-Ivens S. Changes in hemodynamic responses in chronic stroke survivors do not affect fMRI signal detection in a block experimental design. Magn Reson Imaging 2013; 31:1119-28. [PMID: 23642802 DOI: 10.1016/j.mri.2013.02.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 01/22/2013] [Accepted: 02/20/2013] [Indexed: 10/26/2022]
Abstract
The use of canonical functions to model BOLD-fMRI data in people post-stroke may lead to inaccurate descriptions of task-related brain activity. The purpose of this study was to determine whether the spatiotemporal profile of hemodynamic responses (HDRs) obtained from stroke survivors during an event-related experiment could be used to develop individualized HDR functions that would enhance BOLD-fMRI signal detection in block experiments. Our long term goal was to use this information to develop individualized HDR functions for stroke survivors that could be used to analyze brain activity associated with locomotor-like movements. We also aimed to examine the reproducibility of HDRs obtained across two scan sessions in order to determine whether data from a single event-related session could be used to analyze block data obtained in subsequent sessions. Results indicate that the spatiotemporal profile of HDRs measured with BOLD-fMRI in stroke survivors was not the same as that observed in individuals without stroke. We observed small between-group differences in the rates of rise and decline of HDRs that were more apparent in individuals with cortical as compared to subcortical stroke. There were no differences in the peak or time to peak of HDRs in people with and without stroke. Of interest, differences in HDRs were not as substantial as expected from previous reports and were not large enough to necessitate the use of individualized HDR functions to obtain valid measures of movement-related brain activity. We conclude that all strokes do not affect the spatiotemporal characteristics of HDRs in such a way as to produce inaccurate representations of brain activity as measured by BOLD-fMRI. However, care should be taken to identify individuals whose BOLD-fMRI data may not provide an accurate representation of underlying brain activation when canonical models are used. Examination of HDRs need not be done for each scan session, as our data suggest that the characteristics of HDRs in stroke survivors are reproducible across days.
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Affiliation(s)
- Nutta-On Promjunyakul
- Department of Physical Therapy, Marquette University, P.O. Box 1881, Milwaukee, WI 53201-1881, USA.
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31
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Obrig H. NIRS in clinical neurology - a 'promising' tool? Neuroimage 2013; 85 Pt 1:535-46. [PMID: 23558099 DOI: 10.1016/j.neuroimage.2013.03.045] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 03/14/2013] [Accepted: 03/21/2013] [Indexed: 12/13/2022] Open
Abstract
Near-infrared spectroscopy (NIRS) has become a relevant research tool in neuroscience. In special populations such as infants and for special tasks such as walking, NIRS has asserted itself as a low resolution functional imaging technique which profits from its ease of application, portability and the option to co-register other neurophysiological and behavioral data in a 'near natural' environment. For clinical use in neurology this translates into the option to provide a bed-side oximeter for the brain, broadly available at comparatively low costs. However, while some potential for routine brain monitoring during cardiac and vascular surgery and in neonatology has been established, NIRS is largely unknown to clinical neurologists. The article discusses some of the reasons for this lack of use in clinical neurology. Research using NIRS in three major neurologic diseases (cerebrovascular disease, epilepsy and headache) is reviewed. Additionally the potential to exploit the established position of NIRS as a functional imaging tool with regard to clinical questions such as preoperative functional assessment and neurorehabilitation is discussed.
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Affiliation(s)
- Hellmuth Obrig
- Clinic for Cognitive Neurology, University Clinic Leipzig, Leipzig, Germany; Max-Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Dept. Neurology, Charité, University Medicine Berlin, Berlin, Germany.
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Crinion J, Holland AL, Copland DA, Thompson CK, Hillis AE. Neuroimaging in aphasia treatment research: quantifying brain lesions after stroke. Neuroimage 2012; 73:208-14. [PMID: 22846659 DOI: 10.1016/j.neuroimage.2012.07.044] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 06/20/2012] [Accepted: 07/22/2012] [Indexed: 10/28/2022] Open
Abstract
New structural and functional neuroimaging methods continue to rapidly develop, offering promising tools for cognitive neuroscientists. In the last 20 years, advanced magnetic resonance imaging (MRI) techniques have provided invaluable insights into how language is represented and processed in the brain and how it can be disrupted by damage to, or dysfunction of, various parts of the brain. Current functional MRI (fMRI) approaches have also allowed researchers to purposefully investigate how individuals recover language after stroke. This paper presents recommendations for quantification of brain lesions derived from discussions among international researchers at the Neuroimaging in Aphasia Treatment Research Workshop held at Northwestern University (Evanston, Illinois, USA). Methods for detailing and characterizing the brain damage that can influence results of fMRI studies in chronic aphasic stroke patients are discussed. Moreover, we aimed to provide the reader with a set of general practical guidelines and references to facilitate choosing adequate structural imaging strategies that facilitate fMRI studies in aphasia treatment research.
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Affiliation(s)
- Jenny Crinion
- University College London, Institute of Cognitive Neuroscience, London, UK.
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33
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Impaired hemodynamic response in the ischemic brain assessed with BOLD fMRI. Neuroimage 2012; 61:579-90. [DOI: 10.1016/j.neuroimage.2012.04.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2011] [Revised: 03/29/2012] [Accepted: 04/01/2012] [Indexed: 11/21/2022] Open
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Obrig H, Steinbrink J. Non-invasive optical imaging of stroke. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2011; 369:4470-94. [PMID: 22006902 DOI: 10.1098/rsta.2011.0252] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The acute onset of a neurological deficit is the key clinical feature of stroke. In most cases, however, pathophysiological changes in the cerebral vasculature precede the event, often by many years. Persisting neurological deficits may also require long-term rehabilitation. Hence, stroke may be considered a chronic disease, and diagnostic and therapeutic efforts must include identification of specific risk factors, and the monitoring of and interventions in the acute and subacute stages, and should aim at a pathophysiologically based approach to optimize the rehabilitative effort. Non-invasive optical techniques have been experimentally used in all three stages of the disease and may complement the established diagnostic and monitoring tools. Here, we provide an overview of studies using the methodology in the context of stroke, and we sketch perspectives of how they may be integrated into the assessment of the highly dynamic pathophysiological processes during the acute and subacute stages of the disease and also during rehabilitation and (secondary) prevention of stroke.
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Affiliation(s)
- Hellmuth Obrig
- Department of Cognitive Neurology, University Hospital Leipzig, Liebigstraße 16, 04103 Leipzig, Germany.
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35
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Polonara G, Salvolini S, Fabri M, Mascioli G, Cavola GL, Neri P, Mariotti C, Giovannini A, Salvolini U. Unilateral visual loss due to ischaemic injury in the right calcarine region: a functional magnetic resonance imaging and diffusion tension imaging follow-up study. Int Ophthalmol 2011; 31:129-34. [PMID: 21293901 DOI: 10.1007/s10792-011-9420-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2009] [Accepted: 01/01/2011] [Indexed: 10/18/2022]
Abstract
To study the functional recovery of a patient with cerebrovascular injury using combined functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI). A 24-year-old woman with left hemianopsia underwent fMRI and DTI in a 1.5-tesla machine both in the acute phase and 1 month after an ischaemic stroke involving the right calcarine cortex. Acute-phase fMRI demonstrated that peripheral left visual field stimulation did not activate the right primary visual cortex, whereas stimulation 1 month later activated the visual cortex bilaterally. Analysis of acute-phase DTI data disclosed that a reduction of fractional anisotropy in the right optic radiation had almost resolved after 1 month. Fibre direction was normal at either time point. fMRI and DTI can demonstrate functional damage and recovery in patients with neuro-ophthalmological lesions.
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Affiliation(s)
- Gabriele Polonara
- Sezione Scienze Radiologiche, Dipartimento di Scienze Cliniche Specialistiche ed Odontostomatologiche, Università Politecnica delle Marche, Ancona, Italy,
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36
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Leff DR, Orihuela-Espina F, Elwell CE, Athanasiou T, Delpy DT, Darzi AW, Yang GZ. Assessment of the cerebral cortex during motor task behaviours in adults: A systematic review of functional near infrared spectroscopy (fNIRS) studies. Neuroimage 2011; 54:2922-36. [PMID: 21029781 DOI: 10.1016/j.neuroimage.2010.10.058] [Citation(s) in RCA: 273] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Revised: 10/14/2010] [Accepted: 10/15/2010] [Indexed: 10/18/2022] Open
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37
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Stefan H, Rampp S, Knowlton RC. Magnetoencephalography adds to the surgical evaluation process. Epilepsy Behav 2011; 20:172-7. [PMID: 20934391 DOI: 10.1016/j.yebeh.2010.09.011] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Accepted: 09/08/2010] [Indexed: 11/25/2022]
Abstract
Summarizing the podium discussion at the AES 2009, strengths and limitations of magnetoencephalography (MEG) are discussed with regard to basic methodological and clinical aspects in routine screening and presurgical evaluation of patients with epilepsies. Current literature and example cases are used to illustrate MEG contribution to clinical decision making, specifically whether a patient with pharmacoresistant epilepsy can move forward to epilepsy surgery. The main conclusion is that the largest role of MEG, as presently performed in the clinical environment, is to increase the number of patients who can go on to surgery, while it should not be used to deny surgery to any patient.
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Affiliation(s)
- H Stefan
- Epilepsy Center, Neurological Clinic, University Hospital Erlangen-Nuremberg at Erlangen, Erlangen, Germany.
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38
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Mazzetto-Betti KC, Leoni RF, Pontes-Neto OM, Santos AC, Leite JP, Silva AC, de Araujo DB. The stability of the blood oxygenation level-dependent functional MRI response to motor tasks is altered in patients with chronic ischemic stroke. Stroke 2010; 41:1921-6. [PMID: 20705926 DOI: 10.1161/strokeaha.110.590471] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Functional MRI is a powerful tool to investigate recovery of brain function in patients with stroke. An inherent assumption in functional MRI data analysis is that the blood oxygenation level-dependent (BOLD) signal is stable over the course of the examination. In this study, we evaluated the validity of such assumption in patients with chronic stroke. METHODS Fifteen patients performed a simple motor task with repeated epochs using the paretic and the unaffected hand in separate runs. The corresponding BOLD signal time courses were extracted from the primary and supplementary motor areas of both hemispheres. Statistical maps were obtained by the conventional General Linear Model and by a parametric General Linear Model. RESULTS Stable BOLD amplitude was observed when the task was executed with the unaffected hand. Conversely, the BOLD signal amplitude in both primary and supplementary motor areas was progressively attenuated in every patient when the task was executed with the paretic hand. The conventional General Linear Model analysis failed to detect brain activation during movement of the paretic hand. However, the proposed parametric General Linear Model corrected the misdetection problem and showed robust activation in both primary and supplementary motor areas. CONCLUSIONS The use of data analysis tools that are built on the premise of a stable BOLD signal may lead to misdetection of functional regions and underestimation of brain activity in patients with stroke. The present data urge the use of caution when relying on the BOLD response as a marker of brain reorganization in patients with stroke.
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Affiliation(s)
- Kelley C Mazzetto-Betti
- Department of Neuroscience and Behavoral Sciences, FMRP, University of Sao Paulo, Ribeirao Preto, Brazil
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39
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Jann K, Koenig T, Dierks T, Boesch C, Federspiel A. Association of individual resting state EEG alpha frequency and cerebral blood flow. Neuroimage 2010; 51:365-72. [DOI: 10.1016/j.neuroimage.2010.02.024] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Revised: 02/03/2010] [Accepted: 02/10/2010] [Indexed: 10/19/2022] Open
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40
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Wang L, Yu C, Chen H, Qin W, He Y, Fan F, Zhang Y, Wang M, Li K, Zang Y, Woodward TS, Zhu C. Dynamic functional reorganization of the motor execution network after stroke. Brain 2010; 133:1224-38. [DOI: 10.1093/brain/awq043] [Citation(s) in RCA: 458] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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41
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Comparison of somatosensory evoked potentials and cerebral blood oxygenation changes in the sensorimotor cortex during activation in the rat. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010. [PMID: 20204799 DOI: 10.1007/978-1-4419-1241-1_35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
The relationship between changes in cerebral blood oxygenation and neuronal activity remains to be fully established. We compared somatosensory evoked potentials (SEP) and evoked cerebral blood oxygenation (CBO) changes in the sensorimotor cortex of the rat. In rats anesthetized with urethane and alpha-chloralose, we measured SEP and CBO using visible light spectroscopy (VLS) during neuronal activity. Increase of stimulus frequency caused a decrease of SEP amplitude, but an increase in concentration changes of deoxy-Hb and oxygen saturation. The difference in frequency responses between SEP and CBO might be caused by activation of inhibitory neurons, which could suppress excitatory neurons at high stimulus frequencies; activation of inhibitory neurons could reduce SEP amplitude, and increase oxygen saturation due to an increase of evoked cerebral blood flow.
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Altamura C, Reinhard M, Vry MS, Kaller CP, Hamzei F, Vernieri F, Rossini PM, Hetzel A, Weiller C, Saur D. The longitudinal changes of BOLD response and cerebral hemodynamics from acute to subacute stroke. A fMRI and TCD study. BMC Neurosci 2009; 10:151. [PMID: 20021696 PMCID: PMC2805667 DOI: 10.1186/1471-2202-10-151] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Accepted: 12/20/2009] [Indexed: 11/18/2022] Open
Abstract
Background By mapping the dynamics of brain reorganization, functional magnetic resonance imaging MRI (fMRI) has allowed for significant progress in understanding cerebral plasticity phenomena after a stroke. However, cerebro-vascular diseases can affect blood oxygen level dependent (BOLD) signal. Cerebral autoregulation is a primary function of cerebral hemodynamics, which allows to maintain a relatively constant blood flow despite changes in arterial blood pressure and perfusion pressure. Cerebral autoregulation is reported to become less effective in the early phases post-stroke. This study investigated whether any impairment of cerebral hemodynamics that occurs during the acute and the subacute phases of ischemic stroke is related to changes in BOLD response. We enrolled six aphasic patients affected by acute stroke. All patients underwent a Transcranial Doppler to assess cerebral autoregulation (Mx index) and fMRI to evaluate the amplitude and the peak latency (time to peak-TTP) of BOLD response in the acute (i.e., within four days of stroke occurrence) and the subacute (i.e., between five and twelve days after stroke onset) stroke phases. Results As patients advanced from the acute to subacute stroke phase, the affected hemisphere presented a BOLD TTP increase (p = 0.04) and a deterioration of cerebral autoregulation (Mx index increase, p = 0.046). A similar but not significant trend was observed also in the unaffected hemisphere. When the two hemispheres were grouped together, BOLD TTP delay was significantly related to worsening cerebral autoregulation (Mx index increase) (Spearman's rho = 0.734; p = 0.01). Conclusions The hemodynamic response function subtending BOLD signal may present a delay in peak latency that arises as patients advance from the acute to the subacute stroke phase. This delay is related to the deterioration of cerebral hemodynamics. These findings suggest that remodeling the fMRI hemodynamic response function in the different phases of stroke may optimize the detection of BOLD signal changes.
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Affiliation(s)
- Claudia Altamura
- Neurologia Clinica, Università Campus Bio-Medico di Roma, Italy.
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43
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Effects of Revascularisation on Evoked Cerebral Blood Oxygenation Responses in Stroke Patients. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 662:525-30. [DOI: 10.1007/978-1-4419-1241-1_76] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
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44
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Furuta A, Nakadomari S, Misaki M, Miyauchi S, Iida T. Objective perimetry using functional magnetic resonance imaging in patients with visual field loss. Exp Neurol 2009; 217:401-6. [DOI: 10.1016/j.expneurol.2009.03.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2008] [Revised: 02/20/2009] [Accepted: 03/24/2009] [Indexed: 11/24/2022]
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45
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Kokotilo KJ, Eng JJ, Boyd LA. Reorganization of brain function during force production after stroke: a systematic review of the literature. J Neurol Phys Ther 2009; 33:45-54. [PMID: 19265770 PMCID: PMC3186814 DOI: 10.1097/npt.0b013e31819824f0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND AND PURPOSE Damage to motor areas of the brain caused by stroke can produce devastating motor deficits, including aberrant control of force. Reorganization of brain function is a fundamental mechanism involved in recovery of motor control after stroke, and recent advances in neuroimaging have enabled study of this reorganization. This review focuses on neuroimaging studies that have examined reorganization of brain function during force production and force modulation after stroke. METHODS The type and extent of reorganization after stroke were characterized by three factors: severity of injury, time after stroke, and impact of therapeutic interventions on brain activation during force production. Twenty-six studies meeting the inclusion criteria could be identified in MEDLINE (1980-2007). RESULTS Relevant characteristics of studies (lesion location, chronicity of stroke, and motor task) and mapping techniques varied. During force production, increased activation in secondary motor areas occurred in persons with more severe strokes. Reduced recruitment of secondary motor areas during force production was found as a function of increased time since stroke. During force modulation, increased activation in motor areas occurred with greater force generation. Persons with more severe stroke showed greater activation with increasing force compared with persons with less severe stroke. Alteration of brain activation during and after rehabilitative interventions was identified in some studies. DISCUSSION AND CONCLUSION This systematic review establishes that reorganization of brain function during force production and force modulation can occur after stroke. These findings imply that therapeutic strategies may target brain reorganization to improve force control and functional recovery after stroke.
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Affiliation(s)
- Kristen J Kokotilo
- Graduate Program in Neuroscience, University of British Columbia, Vancouver, Canada
- Rehabilitation Research Lab, GF Strong Rehab Centre, Vancouver, Canada
| | - Janice J Eng
- Graduate Program in Neuroscience, University of British Columbia, Vancouver, Canada
- Rehabilitation Research Lab, GF Strong Rehab Centre, Vancouver, Canada
- Department of Physical Therapy, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Lara A Boyd
- Graduate Program in Neuroscience, University of British Columbia, Vancouver, Canada
- Department of Physical Therapy, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
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Abookasis D, Lay CC, Mathews MS, Linskey ME, Frostig RD, Tromberg BJ. Imaging cortical absorption, scattering, and hemodynamic response during ischemic stroke using spatially modulated near-infrared illumination. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:024033. [PMID: 19405762 PMCID: PMC2868516 DOI: 10.1117/1.3116709] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
We describe a technique that uses spatially modulated near-infrared (NIR) illumination to detect and map changes in both optical properties (absorption and reduced scattering parameters) and tissue composition (oxy- and deoxyhemoglobin, total hemoglobin, and oxygen saturation) during acute ischemic injury in the rat barrel cortex. Cerebral ischemia is induced using an open vascular occlusion technique of the middle cerebral artery (MCA). Diffuse reflected NIR light (680 to 980 nm) from the left parietal somatosensory cortex is detected by a CCD camera before and after MCA occlusion. Monte Carlo simulations are used to analyze the spatial frequency dependence of the reflected light to predict spatiotemporal changes in the distribution of tissue absorption and scattering properties in the brain. Experimental results from seven rats show a 17+/-4.7% increase in tissue concentration of deoxyhemoglobin and a 45+/-3.1, 23+/-5.4, and 21+/-2.2% decrease in oxyhemoglobin, total hemoglobin concentration and cerebral tissue oxygen saturation levels, respectively, 45 min following induction of cerebral ischemia. An ischemic index (I(isch)=ctHHbctO(2)Hb) reveals an average of more then twofold contrast after MCAo. The wavelength-dependence of the reduced scattering (i.e., scatter power) decreased by 35+/-10.3% after MCA occlusion. Compared to conventional CCD-based intrinsic signal optical imaging (ISOI), the use of structured illumination and model-based analysis allows for generation of separate maps of light absorption and scattering properties as well as tissue hemoglobin concentration. This potentially provides a powerful approach for quantitative monitoring and imaging of neurophysiology and metabolism with high spatiotemporal resolution.
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Affiliation(s)
- David Abookasis
- University of California Irvine, Beckman Laser Institute and Medical Clinic, 1002 Health Sciences Road East, Irvine, California 92612, USA
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Modo M. Long-term survival and serial assessment of stroke damage and recovery - practical and methodological considerations. ACTA ACUST UNITED AC 2009; 2:52-68. [PMID: 22389748 DOI: 10.6030/1939-067x-2.2.52] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Impairments caused by stroke remain the main cause for adult disability. Despite a vigorous research effort, only 1 thrombolytic treatment has been approved in acute stroke (<3h). The limitations of preclinical studies and how these can be overcome have been the subject of various guidelines. However, often these guidelines focus on the acute stroke setting and omit long-term outcome measures, such as behaviour and neuroimaging. The considerations and practicalities of including the serial assessment of these approaches and their significance to establish therapeutic efficacy are discussed here.
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Affiliation(s)
- Michel Modo
- King's College London, Institute of Psychiatry, Department of Neuroscience, London, UK
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KUNZ ALEXANDER, IADECOLA COSTANTINO. Cerebral vascular dysregulation in the ischemic brain. HANDBOOK OF CLINICAL NEUROLOGY 2009; 92:283-305. [PMID: 18790280 PMCID: PMC3982865 DOI: 10.1016/s0072-9752(08)01914-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Fair DA, Snyder AZ, Connor LT, Nardos B, Corbetta M. Task-evoked BOLD responses are normal in areas of diaschisis after stroke. Neurorehabil Neural Repair 2008; 23:52-7. [PMID: 18796542 DOI: 10.1177/1545968308317699] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE Cerebral infarction can cause diaschisis, a reduction of blood flow and metabolism in areas of the cortex distant from the site of the lesion. Although the functional magnetic resonance imaging (fMRI) blood oxygen level dependent (BOLD) signal is increasingly used to examine the neural correlates of recovery in stroke, its reliability in areas of diaschisis is uncertain. DESIGN The effect of chronic diaschisis as measured by resting positron emission tomography on task-evoked BOLD responses during word-stem completion in a block design fMRI study was examined in 3 patients, 6 months after a single left hemisphere stroke involving the inferior frontal gyrus and operculum. RESULTS The BOLD responses were minimally affected in areas of chronic diaschisis. CONCLUSIONS Within the confines of this study, the mechanism underlying the BOLD signal, which includes a mismatch between neuronally driven increases in blood flow and a corresponding increase in oxygen use, appears to be intact in areas of chronic diaschisis.
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Affiliation(s)
- Damien A Fair
- Department of Neurology, Washington University School of Medicine, St Louis, Missouri 63110, USA.
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Leyba L, Mayer AR, Gollub RL, Andreasen NC, Clark VP. Smoking status as a potential confound in the BOLD response of patients with schizophrenia. Schizophr Res 2008; 104:79-84. [PMID: 18684594 PMCID: PMC2577169 DOI: 10.1016/j.schres.2008.06.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Revised: 06/16/2008] [Accepted: 06/18/2008] [Indexed: 10/21/2022]
Abstract
BACKGROUND Functional magnetic resonance imaging (FMRI) studies comparing schizophrenia patients and controls may have been confounded by the vascular effects of heavier long-term cigarette use in patients. METHODS The blood oxygen level dependent (BOLD) response to a simple sensorimotor task was compared between schizophrenia patient with a smoking history (mean 17 pack years) and carefully matched patient non-smokers and control non-smokers. RESULTS Group differences in activation magnitude and spatial extent were non-significant. CONCLUSIONS Typical smoking histories in schizophrenia patients do not significantly confound FMRI results in simple sensorimotor tasks when patient demographics are carefully controlled.
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Affiliation(s)
- Leonard Leyba
- The Mind Research Network, Pete & Nancy Domenici Hall, 1101 Yale Blvd. NE, Albuquerque, NM 87131, United States.
| | - Andrew R. Mayer
- The Mind Research Network, Pete & Nancy Domenici Hall, 1101 Yale Blvd. NE, Albuquerque, NM 87131, University of New Mexico Health Sciences Center, Department of Neurology, Albuquerque NM, 87131-0001
| | - Randy L. Gollub
- The Mind Research Network, Pete & Nancy Domenici Hall, 1101 Yale Blvd. NE, Albuquerque, NM 87131, Massachusetts General Hospital, Department of Psychiatry, 149 13th St. Charlestown, MA 02129-2000
| | - Nancy C. Andreasen
- The Mind Research Network, Pete & Nancy Domenici Hall, 1101 Yale Blvd. NE, Albuquerque, NM 87131, University of Iowa, Roy J. and Lucille A. Carver College of Medicine, Department of Psychiatry, 200 Hawkins Drive, Iowa City, IA 42242
| | - Vincent P. Clark
- The Mind Research Network, Pete & Nancy Domenici Hall, 1101 Yale Blvd. NE, Albuquerque, NM 87131, University of New Mexico Health Sciences Center, Department of Neurosciences, Albuquerque, NM 87131-0001, University of New Mexico, Department of Psychology, Albuquerque, NM 87131-1161
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