[Review of stimulation parameters of scalp-electroacupuncture for ischemic stroke]

Scalp-electroacupuncture (scalp-EA) is an effective traditional Chinese medicine characteristic therapy for ischemic stroke and frequently employed in clinical practice, but there is still lack of normative standard of stimulation parameters. After searching the relevant articles, we summed up the stimulation parameters of scalp-EA for ischemic stroke from 5 aspects： 1) stimulating frequency (Low frequency is better when continuous waveform is used, and high frequency is better when dense-sparce waveform or discontinuous waveform employed), 2) waveform (Dense-sparce or discontinuous waves are better than continuous waves), 3) intensity (A tolerable stimulation strength may result in better outcomes), 4) needle retention time (In general, the needle retention time is 30 min, but still needing being determined), treatment course (Some studies showed that once a day EA for 3 continuous days is effective, 7 days, significantly effective, 14 days, further enhanced in the therapeutic effect), and 5) intervention time window (Generally, EA intervention within 6 h was mostly effective, shown by animal study). However, these parameters do not exist independently, and they can influence and interact with each other. It is difficult to observe the interaction among parameters only with single-dimension analysis. Hence, more and larger sample size studies, with strict inclusion and exclusion criteria, more reasonable research design (such as multiple factorial design, orthogonal experimental design, etc.) and multiple levels effect analysis are warranted.