Effectiveness of theta and gamma electroacupuncture for post-stroke patients on working memory and electrophysiology: study protocol for a double-center, randomized, patient- and assessor-blinded, sham-controlled, parallel, clinical trial

Practitioners of complementary and alternative medicine have suggested that electroacupuncture (EA) could improve post-stroke cognitive impairment, based on the clinical evidence. This study protocol is aimed at showing the effectiveness of theta and gamma EA for post-stroke patients on working memory (WM) and electrophysiology. After assessing their eligibility, 66 patients with stroke will be enrolled from two Chinese medicine hospitals and randomly divided into theta frequency EA group, gamma frequency EA group, and sham-EA group according to the ratio of 1:1:1. All patients will receive 20 sessions of EA procedures for 4 weeks. Patients in three groups will receive EA at two same acupoints in the head: Baihui (GV20) and Shenting (GV24). The frequency of the three groups of EA is set as follows: 6 Hz (theta-EA group), 40 Hz (gamma-EA group), and no current through the electrodes (sham EA). Patients and assessors will be blinded throughout the entire study. The primary outcome is the performance accuracy of 1-back task which is a frequently used measure of WM in cognitive neuroscience research contexts. Secondary outcome measures will include the response time of 1-back task, the Rivermead Behavioral Memory Test, Trail Making Test, Loewenstein Occupational Therapy Cognitive Assessment Scale, modified Barthel Index, and electroencephalogram (EEG) signals during 1-back tasks. A blinding index will be assessed. Data will be statistically analyzed by one-way ANOVA, at 5% of significance level. We expect this double-center, randomized, patient- and assessor-blinded, sham-controlled, parallel, clinical trial to explore the effectiveness of theta and gamma EA therapy, compared with sham EA, for post-stroke WM. Chinese Clinical Trial Registry, ChiCTR2000031995 . Registered on 17 April 2020.