Electroencephalography Network Indices as Biomarkers of Upper Limb Impairment in Chronic Stroke

Our protocol can help investigate a task-specific neuroactivity for patient with a stroke, thereby finding potential biomarkers for the degree of motor impairments and motor recovery in them. Our technique utilizes task-specific EEG to reveal intricate inflammation processing related to motor impairments in stroke patients. This includes uncovering the interplay between the ipsilesional and contralesional hemispheres.

This method assesses the neurophysiology of motor impairment in stroke patients. When combined with motor function evaluation, it offers a comprehensive analysis of their motor deficits. The indices measured with this paradigm have the potential as a biomarker for optic recovery in patient with stroke.

For the research, utilizing this paradigm will provide insights into the neurophysiology of motor deficit and recovery. After recruiting the patients. Display two visual stimuli, close and open, for 30 seconds each on the center of a monitor to measure baseline resting state electroencephalogram, or EEG, data.

During which the participant closes and opens the eyes. Next, present a hand motion image for three seconds to instruct the participant to make a hand extension move. Follow this by displaying a fixation mark for five seconds, allowing for a resting period.

Seat the participant in a comfortable armchair facing a monitor. To ensure accurate EEG measurements, select an appropriately-sized EEG cap based on the participant's head size. Locate the Cz position based on the International 10-20 System as described in the manuscript, and position it to align the Cz electrode with the individual's Cz location.

Once the EEG cap is properly placed, attach 32 silver/silver-chloride scalp electrodes to the scalp, following the extended International 10-10 System with the ground and reference electrodes at FPz and FCz respectively. Turn on the EEG system. Go to Configuration, then select Amplifier.

Choose LiveAmp and click on OK.Search for the LiveAmp function to establish a wireless connection. Then, adjust the impedance level between the EEG electrodes and scalp using conductive gel. Use the gel to fix hair to avoid obstructing electrodes and the scalp.

Execute the Impedance Check function to monitor the impedance level of each electrode. Next, execute the Monitoring function to confirm all electrodes have similar amplitude levels in real-time EEG signal monitoring. For stable EEG data acquisition, use two separate personal computers for presenting external stimuli and recording EEG data.

Then create a stimulation program for presenting experimental stimuli to participants using programming software based on the experimental paradigm. Execute the program in Monitoring Mode to present experimental stimuli. Confirm that the event information is accurately marked at the bottom of the EEG recording software each time a stimulus is displayed.

Initiate the EEG recording software and run the stimulus presentation program developed according to the experimental paradigm using programming software to avoid data omission. Then, proceed to measure EEG at a 1, 000 hertz sampling rate, following the experimental paradigm. The topographical low beta ERD maps of each hand movement task are shown.

A significantly strong low beta ERD was observed in the contralesional hemisphere compared to the ipsilesional hemisphere for both the affected and unaffected hand movement tasks. The quantitative results of the four weighted global level network characteristics showed that both the strength and clustering coefficient indices were significantly reduced during the affected hand movement task compared with the unaffected hand movement task. The path length significantly increased during the affected hand movement task.

There was no significant difference in small-worldness between the two tasks. The alpha band ipsicontralesional network strength clustering coefficient and small-worldness showed a positive correlation with the FMA score, while path length was negatively correlated with the FMA score. To obtain high-quality EEG data, it is crucial to correctly place the EEG electrodes in their designated positions and regulate the impedance level between the electrodes and the scalp.

The technique evaluates the neurophysiology of motor impairment of patients with stroke in the clinical laboratory setting. It'll provide opportunities for clinical researchers to investigate the neurophysiology of motor impairment.