Non Invasive Brain Stimulation Study Based on Ischemic Stroke Patients

Area of Science:

• Neuroscience
• Medical Engineering
• Rehabilitation Medicine

Background:

• Non-invasive brain stimulation (NIBS) is increasingly utilized for neuromodulation with promising clinical applications.
• Sub-acute ischemic stroke patients present a key demographic for exploring advanced neurorehabilitation techniques.

Purpose of the Study:

• To investigate significant variations in near-infrared spectroscopy (NIRS) signals (cerebral oxygenation, oxy-hemoglobin, deoxy-hemoglobin) before and after transcranial direct current stimulation (tDCS) in sub-acute ischemic stroke patients.
• To classify healthy and lesioned hemispheres based on NIRS parameter changes post-tDCS.

Main Methods:

• Utilized experimental NIRS-tDCS raw data from twenty-two sub-acute ischemic stroke patients.
• Employed Pearson correlation to analyze relationships between hemodynamic responses.
• Applied one-sample t-test to assess significant pre- to post-tDCS changes in NIRS parameters (HbO2, Hb, rSO2) at a 99% confidence interval (P<0.01).

Main Results:

• A significant negative correlation was observed between oxy-hemoglobin and deoxy-hemoglobin before and after tDCS (P<0.01).
• Healthy hemispheres showed a significant increase in regional cerebral oxygenation (rSO2) post-tDCS.
• Lesioned hemispheres exhibited varied responses: one showed a significant decrease in rSO2, while another displayed negligible change.

Conclusions:

• NIRS parameters (HbO2, Hb, rSO2) demonstrate significant changes following tDCS, enabling hemisphere classification in stroke patients.
• NIBS, specifically tDCS combined with NIRS, offers a potential method for assessing and potentially modulating brain activity in stroke rehabilitation.
• Hemodynamic responses in lesioned hemispheres post-tDCS are complex and require further investigation to understand underlying mechanisms.