Noninvasive brain stimulation after stroke: it is time for large randomized controlled trials!

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Biomedical Engineering

Background:

• Stroke significantly impairs motor function, necessitating effective recovery strategies.
• Noninvasive neuromodulation techniques offer potential for enhancing motor system function post-stroke.

Purpose of the Study:

• To review recent studies on noninvasive neuromodulation for motor function recovery after stroke.
• To evaluate the efficacy of different stimulation techniques and timing in stroke rehabilitation.

Main Methods:

• Review of recent longitudinal and randomized controlled trials.
• Analysis of studies employing repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS).
• Examination of stimulation strategies targeting ipsilesional and contralesional motor cortices.

Main Results:

• Repetitive transcranial magnetic stimulation (rTMS) combined with motor training improves motor performance, particularly in the early post-stroke phase.
• Transcranial direct current stimulation (tDCS) shows limited benefit in the early post-stroke phase but can be effective in the chronic phase when combined with training.
• Bihemispheric stimulation strategies, especially with rTMS, appear promising for stroke recovery.

Conclusions:

• Noninvasive brain stimulation techniques show promise in supporting motor recovery after stroke.
• Sufficiently powered randomized controlled trials are needed to validate these findings.
• Future research should consider clinical heterogeneity in stroke patient populations for optimized protocols.