Decoding Upper Limb Movement Attempt From EEG Measurements of the Contralesional Motor Cortex in Chronic Stroke Patients

2017 ◽  
Vol 64 (1) ◽  
pp. 99-111 ◽  
Author(s):  
Javier M. Antelis ◽  
Luis Montesano ◽  
Ander Ramos-Murguialday ◽  
Niels Birbaumer ◽  
Javier Minguez
2019 ◽  
Vol 33 (2) ◽  
pp. 130-140 ◽  
Author(s):  
Ronan A. Mooney ◽  
Suzanne J. Ackerley ◽  
Deshan K. Rajeswaran ◽  
John Cirillo ◽  
P. Alan Barber ◽  
...  

Background. Stroke is a leading cause of adult disability owing largely to motor impairment and loss of function. After stroke, there may be abnormalities in γ-aminobutyric acid (GABA)-mediated inhibitory function within primary motor cortex (M1), which may have implications for residual motor impairment and the potential for functional improvements at the chronic stage. Objective. To quantify GABA neurotransmission and concentration within ipsilesional and contralesional M1 and determine if they relate to upper limb impairment and function at the chronic stage of stroke. Methods. Twelve chronic stroke patients and 16 age-similar controls were recruited for the study. Upper limb impairment and function were assessed with the Fugl-Meyer Upper Extremity Scale and Action Research Arm Test. Threshold tracking paired-pulse transcranial magnetic stimulation protocols were used to examine short- and long-interval intracortical inhibition and late cortical disinhibition. Magnetic resonance spectroscopy was used to evaluate GABA concentration. Results. Short-interval intracortical inhibition was similar between patients and controls ( P = .10). Long-interval intracortical inhibition was greater in ipsilesional M1 compared with controls ( P < .001). Patients who did not exhibit late cortical disinhibition in ipsilesional M1 were those with greater upper limb impairment and worse function ( P = .002 and P = .017). GABA concentration was lower within ipsilesional ( P = .009) and contralesional ( P = .021) M1 compared with controls, resulting in an elevated excitation-inhibition ratio for patients. Conclusion. These findings indicate that ipsilesional and contralesional M1 GABAergic inhibition are altered in this small cohort of chronic stroke patients. Further study is warranted to determine how M1 inhibitory networks might be targeted to improve motor function.


Author(s):  
Juan A. Barios ◽  
Santiago Ezquerro ◽  
Arturo Bertomeu-Motos ◽  
Jose M. Catalan ◽  
Jose M. Sanchez-Aparicio ◽  
...  

Conventional rehabilitation strategies for stroke survivors become difficult when voluntary movements are severely disturbed. Combining passive limb mobilization, robotic devices and EEG-based brain-computer interfaces (BCI) systems might improve treatment and clinical follow-up of these patients, but detailed knowledge of neurophysiological mechanisms involved in functional recovery, which might help for tailoring stroke treatment strategies, is lacking. Movement-related EEG changes (EEG event-related desynchronization (ERD) in [Formula: see text] and [Formula: see text] bands, an indicator of motor cortex activation traditionally used for BCI systems), were evaluated in a group of 23 paralyzed chronic stroke patients in two unilateral motor tasks alternating paretic and healthy hands ((i) passive movement, using a hand exoskeleton, and (ii) voluntary movement), and compared to nine healthy subjects. In tasks using unaffected hand, we observed an increase of contralesional hemisphere activation for stroke patients group. Unexpectedly, when using paralyzed hand, motor cortex activation was reduced or absent in severely affected group of patients, while patients with moderate motor deficit showed an activation greater than control group. Cortical activation was reduced or absent in damaged hemisphere of all the patients in both tasks. Significant differences related to severity of motor deficit were found in the time course of [Formula: see text] bands power ratio in EEG of contralesional hemisphere while moving affected hand. These findings suggest the presence of different compensation mechanisms in contralesional hemisphere of stroke patients related to the grade of motor disability, that might turn quantitative EEG during a movement task, obtained from a BCI system controlling a robotic device included in a rehabilitation task, into a valuable tool for monitoring clinical progression, evaluating recovery, and tailoring treatment of stroke patients.


2018 ◽  
Vol 2 (S1) ◽  
pp. 17-17
Author(s):  
Joseph B. Humphries ◽  
David T. Bundy ◽  
Eric C. Leuthardt ◽  
Thy N. Huskey

OBJECTIVES/SPECIFIC AIMS: The objective of this study is to determine the degree to which the use of a contralesionally-controlled brain-computer interface for stroke rehabilitation drives change in interhemispheric motor cortical activity. METHODS/STUDY POPULATION: Ten chronic stroke patients were trained in the use of a brain-computer interface device for stroke recovery. Patients perform motor imagery to control the opening and closing of a motorized hand orthosis. This device was sent home with patients for 12 weeks, and patients were asked to use the device 1 hour per day, 5 days per week. The Action Research Arm Test (ARAT) was performed at 2-week intervals to assess motor function improvement. Before the active motor imagery task, patients were asked to quietly rest for 90 seconds before the task to calibrate recording equipment. EEG signals were acquired from 2 electrodes—one each centered over left and right primary motor cortex. Signals were preprocessed with a 60 Hz notch filter for environmental noise and referenced to the common average. Power envelopes for 1 Hz frequency bands (1–30 Hz) were calculated through Gabor wavelet convolution. Correlations between electrodes were then calculated for each frequency envelope on the first and last 5 runs, thus generating one correlation value per subject, per run. The chosen runs approximately correspond to the first and last week of device usage. These correlations were Fisher Z-transformed for comparison. The first and last 5 run correlations were averaged separately to estimate baseline and final correlation values. A difference was then calculated between these averages to determine correlation change for each frequency. The relationship between beta-band correlation changes (13–30 Hz) and the change in ARAT score was determined by calculating a Pearson correlation. RESULTS/ANTICIPATED RESULTS: Beta-band inter-electrode correlations tended to decrease more in patients achieving greater motor recovery (Pearson’s r=−0.68, p=0.031). A similar but less dramatic effect was observed with alpha-band (8–12 Hz) correlation changes (Pearson’s r=−0.42, p=0.22). DISCUSSION/SIGNIFICANCE OF IMPACT: The negative correlation between inter-electrode power envelope correlations in the beta frequency band and motor recovery indicates that activity in the motor cortex on each hemisphere may become more independent during recovery. The role of the unaffected hemisphere in stroke recovery is currently under debate; there is conflicting evidence regarding whether it supports or inhibits the lesioned hemisphere. These findings may support the notion of interhemispheric inhibition, as we observe less in common between activity in the 2 hemispheres in patients successfully achieving recovery. Future neuroimaging studies with greater spatial resolution than available with EEG will shed further light on changes in interhemispheric communication that occur during stroke rehabilitation.


BMJ Open ◽  
2017 ◽  
Vol 7 (8) ◽  
pp. e016566
Author(s):  
Eline C C van Lieshout ◽  
Johanna M A Visser-Meily ◽  
Sebastiaan F W Neggers ◽  
H Bart van der Worp ◽  
Rick M Dijkhuizen

IntroductionMany patients with stroke have moderate to severe long-term sensorimotor impairments, often including inability to execute movements of the affected arm or hand. Limited recovery from stroke may be partly caused by imbalanced interaction between the cerebral hemispheres, with reduced excitability of the ipsilesional motor cortex while excitability of the contralesional motor cortex is increased. Non-invasive brain stimulation with inhibitory repetitive transcranial magnetic stimulation (rTMS) of the contralesional hemisphere may aid in relieving a post-stroke interhemispheric excitability imbalance, which could improve functional recovery. There are encouraging effects of theta burst stimulation (TBS), a form of TMS, in patients with chronic stroke, but evidence on efficacy and long-term effects on arm function of contralesional TBS in patients with subacute hemiparetic stroke is lacking.Methods and analysisIn a randomised clinical trial, we will assign 60 patients with a first-ever ischaemic stroke in the previous 7–14 days and a persistent paresis of one arm to 10 sessions of real stimulation with TBS of the contralesional primary motor cortex or to sham stimulation over a period of 2 weeks. Both types of stimulation will be followed by upper limb training. A subset of patients will undergo five MRI sessions to assess post-stroke brain reorganisation. The primary outcome measure will be the upper limb function score, assessed from grasp, grip, pinch and gross movements in the action research arm test, measured at 3 months after stroke. Patients will be blinded to treatment allocation. The primary outcome at 3 months will also be assessed in a blinded fashion.Ethics and disseminationThe study has been approved by the Medical Research Ethics Committee of the University Medical Center Utrecht, The Netherlands. The results will be disseminated through (open access) peer-reviewed publications, networks of scientists, professionals and the public, and presented at conferences.Trial registration numberNTR6133


2018 ◽  
Vol 42 (1) ◽  
pp. 43-52 ◽  
Author(s):  
S. Mazzoleni ◽  
E. Battini ◽  
R. Crecchi ◽  
P. Dario ◽  
F. Posteraro

NeuroImage ◽  
1998 ◽  
Vol 7 (4) ◽  
pp. S24
Author(s):  
J. Liepert ◽  
H. Bauder ◽  
M. Sommer ◽  
W.H.R. Miltner ◽  
C. Dettmers ◽  
...  

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