Non-invasive alternating current stimulation induces recovery from stroke.

Area of Science:

• Neuroscience
• Neurology
• Rehabilitation Medicine

Background:

• Stroke recovery can be enhanced by modulating neuroplasticity using non-invasive brain stimulation.
• Repetitive transorbital alternating current stimulation (rtACS) is a novel non-invasive brain stimulation technique.
• A randomized, drug-controlled clinical trial was conducted to assess rtACS effects on stroke recovery.

Purpose of the Study:

• To evaluate the efficacy of rtACS in improving neurological deficits after ischemic stroke.
• To assess the impact of rtACS on motor impairments, sensory loss, visual field defects, and cortical deficits.
• To investigate the effects of rtACS on brain plasticity and interhemispheric synchrony.

Main Methods:

• Ninety-eight ischemic stroke patients (21.4 months post-stroke) were randomized into three groups: drug therapy alone, rtACS alone, or combined therapy.
• Stroke Severity Level (SSL) was assessed using the NIH-NINDS stroke scale before, after treatment, and at 1-month follow-up.
• Standard EEG recordings were performed at each assessment point to monitor brain activity.

Main Results:

• rtACS groups (ACS and D/ACS) showed significant SSL improvements (22.5% and 25.1%) after 12 days, unlike the control group (+3%).
• Improvements were primarily in motor, sensory, and speech functions, with sustained gains at 1-month follow-up (+32.3% and +34.7% total change).
• EEG revealed increased interhemispheric synchrony, positively correlated with clinical recovery.

Conclusions:

• Non-invasive rtACS can effectively modulate brain plasticity in post-stroke patients.
• rtACS facilitates recovery from neurological deficits, even in the chronic phase after stroke.
• This stimulation technique offers a promising avenue for stroke rehabilitation beyond the early recovery window.