Influence of artifacts on movement intention decoding from EEG activity in severely paralyzed stroke patients

Introduction: The majority of our patients with middle cerebral artery (MCA) infarcts have impaired latency of visual saccades, saccadic dysmetria and saccadic intrusions of pursuits. We wanted to see if the utilization of eye movement rehabilitation in cases of middle cerebral artery infarction would result in changes of brain function and patient clinical outcomes. Hypothesis: We assessed the hypothesis that visual training of fast and slow eye movements to novel targets will result in changes in EEG activity, decrease physical and cognitive impairment and increase clinical outcomes in stroke patients. Methods: A sample size of 60 subjects (80% power, alpha of 0.05 at 95% CI) with acute MCA ischemic stroke within the first 48 hours of clinical evolution were randomized to an active treatment (n=30) group that performed eye movement strategies and a matched control group (n= 30) that did not. All subjects underwent CT and MRI and received standard therapies and NIH Stroke Scales and QEEG. Results: A significant reduction of the NIHSS scale was found after a week of practicing our eye movement strategies, indicating a clinical improvement. There was a significant reduction of the DAR index after eye movement exercises. QEEG brain mapping demonstrated a significant reduction of the spectral power in the Delta and an increment in the Alpha bands also demonstrated with the reduction of the DAR index. The brain symmetry index significantly increased after eye movement exercises indicating an augmentation of balance of the absolute mean value of the hemispheric power difference in the frequency range from 1 to 30 Hz. There was a significant reduction of the PRI index after eye movement exercises, indicating an increment of the fast (alpha +beta), compared with the slow (delta + theta) activities. A significant correlation was found between NIHSS (before) and DAR (after). Conclusions: The stroke patients undergoing eyes exercises had a significant neurological recovery with decreased impairment and improvement of electrical brain activity both reflected in the modifications of the NIHSS scale, and the DAR and BSI QEEG indices and strong correlations of DAR post-exercise with NIHSS scores before eye movement training strategies.

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Comparison of Features for Movement Prediction from Single-Trial Movement-Related Cortical Potentials in Healthy Subjects and Stroke Patients

Computational Intelligence and Neuroscience ◽

10.1155/2015/858015 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 15

Author(s):

Ernest Nlandu Kamavuako ◽

Mads Jochumsen ◽

Imran Khan Niazi ◽

Kim Dremstrup

Keyword(s):

Template Matching ◽

Spectral Features ◽

Single Trial ◽

Eeg Signals ◽

Stroke Patients ◽

Movement Execution ◽

Linear Discriminant ◽

Temporal Features ◽

Electroencephalogram Eeg ◽

Movement Intention

Detection of movement intention from the movement-related cortical potential (MRCP) derived from the electroencephalogram (EEG) signals has shown to be important in combination with assistive devices for effective neurofeedback in rehabilitation. In this study, we compare time and frequency domain features to detect movement intention from EEG signals prior to movement execution. Data were recoded from 24 able-bodied subjects, 12 performing real movements, and 12 performing imaginary movements. Furthermore, six stroke patients with lower limb paresis were included. Temporal and spectral features were investigated in combination with linear discriminant analysis and compared with template matching. The results showed that spectral features were best suited for differentiating between movement intention and noise across different tasks. The ensemble average across tasks when using spectral features was (error = 3.4 ± 0.8%, sensitivity = 97.2 ± 0.9%, and specificity = 97 ± 1%) significantly better (P<0.01) than temporal features (error = 15 ± 1.4%, sensitivity: 85 ± 1.3%, and specificity: 84 ± 2%). The proposed approach also (error = 3.4 ± 0.8%) outperformed template matching (error = 26.9 ± 2.3%) significantly (P>0.001). Results imply that frequency information is important for detecting movement intention, which is promising for the application of this approach to provide patient-driven real-time neurofeedback.

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Overactivation of the supplementary motor area in chronic stroke patients

Journal of Neurophysiology ◽

10.1152/jn.00735.2013 ◽

2014 ◽

Vol 112 (9) ◽

pp. 2251-2263 ◽

Cited By ~ 7

Author(s):

Julià L. Amengual ◽

Thomas F. Münte ◽

Josep Marco-Pallarés ◽

Nuria Rojo ◽

Jennifer Grau-Sánchez ◽

...

Keyword(s):

Motor System ◽

Supplementary Motor Area ◽

Temporal Dynamics ◽

Reaction Time Task ◽

Chronic Stroke ◽

Motor Area ◽

Neural Function ◽

Stroke Patients ◽

Response Hand ◽

Eeg Activity

Stroke induces a loss of neural function, but it triggers a complex amount of mechanisms to compensate the associated functional impairment. The present study aims to increase our understanding of the functional reshape of the motor system observed in chronic stroke patients during the preparation and the execution of movements. A cohort of 14 chronic stroke patients with a mild-to-moderate hemiparesis and 14 matched healthy controls were included in this study. Participants were asked to perform a bimanual reaction time task synchronizing alternated responses to the presentation of a visual cue. We used Laplacian-transformed EEG activity (LT-EEG) recorded at the locations Cz and C3/C4 to study the response-locked components associated with the motor system activity during the performance of this task. Behaviorally, patients showed larger variable errors than controls in synchronizing the frequency of execution of responses to the interstimulus interval, as well as slower responses compared with controls. LT-EEG analysis showed that whereas control participants increased their supplementary motor area (SMA) activity during the preparation of all responses, patients only showed an increment of activity over this area during their first response of the sequence. More interestingly, patients showed a clear increment of the LT-EEG activity associated with SMA shortly after motor responses as compared to the control participants. Finally, patients showed a hand-dependent inhibitory activity over motor areas ipsilateral to the response hand. Overall, our findings reveal drastic differences in the temporal dynamics of the LT-EEG components associated with the activity over motor and premotor cortices in chronic stroke patients compared with matched control participants during alternated hand responses.

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A Review of Techniques for Detection of Movement Intention Using Movement-Related Cortical Potentials

Computational and Mathematical Methods in Medicine ◽

10.1155/2015/346217 ◽

2015 ◽

Vol 2015 ◽

pp. 1-13 ◽

Cited By ~ 27

Author(s):

Aqsa Shakeel ◽

Muhammad Samran Navid ◽

Muhammad Nabeel Anwar ◽

Suleman Mazhar ◽

Mads Jochumsen ◽

...

Keyword(s):

Motor Control ◽

Voluntary Movement ◽

Low Frequency ◽

Human Movement ◽

Stroke Patients ◽

Potential Implication ◽

Computer Interfaces ◽

Eeg Data ◽

Direction Of Movement ◽

Movement Intention

The movement-related cortical potential (MRCP) is a low-frequency negative shift in the electroencephalography (EEG) recording that takes place about 2 seconds prior to voluntary movement production. MRCP replicates the cortical processes employed in planning and preparation of movement. In this study, we recapitulate the features such as signal’s acquisition, processing, and enhancement and different electrode montages used for EEG data recoding from different studies that used MRCPs to predict the upcoming real or imaginary movement. An authentic identification of human movement intention, accompanying the knowledge of the limb engaged in the performance and its direction of movement, has a potential implication in the control of external devices. This information could be helpful in development of a proficient patient-driven rehabilitation tool based on brain-computer interfaces (BCIs). Such a BCI paradigm with shorter response time appears more natural to the amputees and can also induce plasticity in brain. Along with different training schedules, this can lead to restoration of motor control in stroke patients.

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Translation Research for the Rehabilitation of Left Spatial Neglect and Associated Disorders of Attention in Stroke Patients

Perspectives on Neurophysiology and Neurogenic Speech and Language Disorders ◽

10.1044/nnsld18.2.55 ◽

2008 ◽

Vol 18 (2) ◽

pp. 55-65 ◽

Cited By ~ 2

Author(s):

Nkiruka Arene ◽

Argye E. Hillis

Keyword(s):

Theoretical Basis ◽

Attention Bias ◽

Spatial Neglect ◽

Clinical Use ◽

Stroke Patients ◽

Translation Research ◽

Unilateral Neglect ◽

Assessment And Treatment ◽

Sound Theoretical Basis ◽

Review Current

Abstract The syndrome of unilateral neglect, typified by a lateralized attention bias and neglect of contralateral space, is an important cause of morbidity and disability after a stroke. In this review, we discuss the challenges that face researchers attempting to elucidate the mechanisms and effectiveness of rehabilitation treatments. The neglect syndrome is a heterogeneous disorder, and it is not clear which of its symptoms cause ongoing disability. We review current methods of neglect assessment and propose logical approaches to selecting treatments, while acknowledging that further study is still needed before some of these approaches can be translated into routine clinical use. We conclude with systems-level suggestions for hypothesis development that would hopefully form a sound theoretical basis for future approaches to the assessment and treatment of neglect.

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