Alpha-tACS Improves Executive Function and Alpha Power Spectral Density in Patients With Post-Stroke Cognitive...

Area of Science:

• Neuroscience
• Neuromodulation
• Cognitive Rehabilitation

Background:

• Post-stroke cognitive impairment (PSCI) affects a significant number of stroke survivors.
• Current treatment options for PSCI have limited efficacy, necessitating novel therapeutic strategies.
• Alpha-frequency transcranial alternating current stimulation (alpha-tACS) is an emerging neuromodulatory technique.

Purpose of the Study:

• To evaluate the efficacy of alpha-tACS in treating PSCI.
• To investigate the effects of alpha-tACS on electroencephalographic (EEG) activity in PSCI patients.
• To determine the potential of alpha-tACS as a cognitive rehabilitation intervention.

Main Methods:

• Forty PSCI patients were randomized into active alpha-tACS (10 Hz, 2 mA over bilateral DLPFC) or sham stimulation groups for 4 weeks.
• Both groups received standard therapy alongside the assigned stimulation.
• Cognitive function was assessed using MoCA and TMT-A/B; resting-state EEG was used to measure alpha power spectral density (PSD) and brain activity metrics (DAR, DTABR).

Main Results:

• The alpha-tACS group showed significant improvements in MoCA scores and TMT-A completion times compared to the sham group (p < 0.05).
• Alpha-tACS led to more pronounced increases in alpha PSD across all electrodes and significant reductions in whole-brain DAR and DTABR values (p_FDR < 0.05).
• Improvements in TMT-A were positively correlated with alpha PSD changes, with P3 electrode PSD difference being a significant predictor (p = 0.01).

Conclusions:

• Alpha-tACS effectively enhances alpha oscillations in the brain.
• This neuromodulation technique significantly improves executive functions in patients with PSCI.
• Alpha-tACS shows promise as a valuable intervention for cognitive rehabilitation after stroke.