A hybrid EEG-EMG BMI improves the detection of movement intention in cortical stroke patients with complete hand paralysis

2018 ◽  
Author(s):  
Eduardo Loopez-Larraz ◽  
Niels Birbaumer ◽  
Ander Ramos-Murguialday
Keyword(s):  
Stroke Patients ◽  
Cortical Stroke ◽  
Movement Intention

scholarly journals Testing Conclusions From Functional Imaging of Working Memory with Data From Acute Stroke

2007 ◽  
Vol 18 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Lisa E. Philipose ◽  
Hannah Alphs ◽  
Vivek Prabhakaran ◽  
Argye E. Hillis
Keyword(s):  
Working Memory ◽  
Acute Stroke ◽  
Functional Imaging ◽  
Right Hemisphere ◽  
Spatial Working Memory ◽  
Verbal Working Memory ◽  
Stroke Patients ◽  
Imaging Results ◽  
Cortical Stroke ◽  
The Right

Functional imaging studies indicate that the left hemisphere mediates verbal working memory, while the right hemisphere mediates both verbal and spatial working memory. We evaluated acute stroke patients with working memory tests and imaging to identify whether unilateral dysfunction causes deficits in spatial and/or verbal working memory deficits. While left cortical stroke patients had verbal working memory impairments (p< 0.003), right cortical stroke patients had both verbal (p< 0.007) and spatial working memory (p< 0.03) impairments, confirming functional imaging results. Patients with transient ischemic stroke and patients with non-cortical stroke did not have significant deficits in working memory in either modality.

scholarly journals Auditory Hallucinations in Acute Stroke

2005 ◽  
Vol 16 (4) ◽  
pp. 211-216 ◽  
Author(s):  
Yair Lampl ◽  
Mordechai Lorberboym ◽  
Ronit Gilad ◽  
Mona Boaz ◽  
Menachem Sadeh
Keyword(s):  
Acute Stroke ◽  
Cross Sectional Study ◽  
Auditory Hallucinations ◽  
Stroke Patients ◽  
Cross Sectional ◽  
Ischemic Lesion ◽  
Cortical Stroke ◽  
The Right ◽  
The Brain

Auditory hallucinations are uncommon phenomena which can be directly caused by acute stroke, mostly described after lesions of the brain stem, very rarely reported after cortical strokes. The purpose of this study is to determine the frequency of this phenomenon. In a cross sectional study, 641 stroke patients were followed in the period between 1996–2000. Each patient underwent comprehensive investigation and follow-up. Four patients were found to have post cortical stroke auditory hallucinations. All of them occurred after an ischemic lesion of the right temporal lobe. After no more than four months, all patients were symptom-free and without therapy. The fact the auditory hallucinations may be of cortical origin must be taken into consideration in the treatment of stroke patients. The phenomenon may be completely reversible after a couple of months.

scholarly journals Brain Symmetry Index in Healthy and Stroke Patients for Assessment and Prognosis

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Andrei Agius Anastasi ◽  
Owen Falzon ◽  
Kenneth Camilleri ◽  
Malcolm Vella ◽  
Richard Muscat
Keyword(s):  
Motor Function ◽  
Visual Cues ◽  
Healthy Controls ◽  
The Novel ◽  
Stroke Patients ◽  
Symmetry Index ◽  
Signal Parameters ◽  
Cortical Stroke ◽  
The Difference

Objective.Quantitative neurophysiological signal parameters are of value in predicting motor recovery after stroke. The novel role of EEG-derived brain symmetry index for motor function prognostication in the subacute phase after stroke is explored.Methods. Ten male stroke patients and ten matched healthy controls were recruited. Motor function was first assessed clinically using the MRC score, its derivative Motricity Index, and the Fugl–Meyer assessment score. EEG was subsequently recorded first with subjects at rest and then during hand grasping motions, triggered by visual cues. Brain symmetry index (BSI) was used to identify the differences in EEG-quantified interhemispheric cortical power asymmetry observable in healthy versus cortical and subcortical stroke patients. Subsequently, any correlation between BSI and motor function was explored.Results. BSI was found to be significantly higher in stroke subjects compared to healthy controls (p=0.023). The difference in BSI was more pronounced in the cortical stroke subgroup (p=0.016). BSI showed only a mild general decrease on repeated monthly recording. Notably, a statistically significant correlation was observed between early BSI and Fugl–Meyer score later in recovery (p<0.050).Conclusions. Brain symmetry index is increased in the subacute poststroke phase and correlates with motor function 1-2 months after stroke.

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

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
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.

Coated–platelets in Ischemic Stroke

US Neurology ◽  
2010 ◽  
Vol 05 (02) ◽  
pp. 55
Author(s):  
Calin I Prodan ◽  
George L Dale ◽  
◽  
Keyword(s):  
Ischemic Stroke ◽  
Biochemical Marker ◽  
Platelet Reactivity ◽  
Lacunar Stroke ◽  
Stroke Patients ◽  
Stroke Subtypes ◽  
Cortical Stroke ◽  
Critical Components ◽  
First Time

While platelets are acknowledged as critical components of ischemic stroke pathophysiology, little is known about the role of platelet reactivity or platelet subclasses in stroke. Coated-platelets are a pro-thrombotic subclass of platelets, levels of which can vary substantially among individuals. Recently, coated-platelets were observed to be elevated in cortical stroke patients and decreased in lacunar stroke patients, thereby providing for the first time a biochemical marker distinguishing these two stroke subtypes. This article reviews the primary observation as well as the clinical and epidemiological implications of this finding.

A longitudinal fMRI study: in recovering and then in clinically stable sub-cortical stroke patients

NeuroImage ◽  
2004 ◽  
Vol 23 (3) ◽  
pp. 827-839 ◽  
Author(s):  
David Tombari ◽  
Isabelle Loubinoux ◽  
Jérémie Pariente ◽  
Angelique Gerdelat ◽  
Jean-François Albucher ◽  
...  
Keyword(s):  
Stroke Patients ◽  
Fmri Study ◽  
Cortical Stroke

scholarly journals A Method to Experimentally Estimate the Conductivity of Chronic Stroke Lesions: A Tool to Individualize Transcranial Electric Stimulation

2021 ◽  
Vol 15 ◽  
Author(s):  
Joris van der Cruijsen ◽  
Maria Carla Piastra ◽  
Ruud W. Selles ◽  
Thom F. Oostendorp
Keyword(s):  
Electric Stimulation ◽  
Estimation Error ◽  
Chronic Stroke ◽  
Stroke Patients ◽  
Estimation Errors ◽  
Experimental Conditions ◽  
Stroke Population ◽  
Cortical Stroke ◽  
Transcranial Electric Stimulation ◽  
Stroke Lesion

The inconsistent response to transcranial electric stimulation in the stroke population is attributed to, among other factors, unknown effects of stroke lesion conductivity on stimulation strength at the targeted brain areas. Volume conduction models are promising tools to determine optimal stimulation settings. However, stroke lesion conductivity is often not considered in these models as a source of inter-subject variability. The goal of this study is to propose a method that combines MRI, EEG, and transcranial stimulation to estimate the conductivity of cortical stroke lesions experimentally. In this simulation study, lesion conductivity was estimated from scalp potentials during transcranial electric stimulation in 12 chronic stroke patients. To do so, first, we determined the stimulation configuration where scalp potentials are maximally affected by the lesion. Then, we calculated scalp potentials in a model with a fixed lesion conductivity and a model with a randomly assigned conductivity. To estimate the lesion conductivity, we minimized the error between the two models by varying the conductivity in the second model. Finally, to reflect realistic experimental conditions, we test the effect rotation of measurement electrode orientation and the effect of the number of electrodes used. We found that the algorithm converged to the correct lesion conductivity value when noise on the electrode positions was absent for all lesions. Conductivity estimation error was below 5% with realistic electrode coregistration errors of 0.1° for lesions larger than 50 ml. Higher lesion conductivities and lesion volumes were associated with smaller estimation errors. In conclusion, this method can experimentally estimate stroke lesion conductivity, improving the accuracy of volume conductor models of stroke patients and potentially leading to more effective transcranial electric stimulation configurations for this population.

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

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
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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