title: Electroencephalogram--entropy and acupuncture.
abstract: Computer-based measuring of the level of sedation and hypnosis is difficult and has proven to be challenging. The electroencephalogram (EEG) has been proposed as a potential method. Response entropy (RE) and state entropy (SE) are multifactor, dimensionless parameters of a new technology of EEG monitoring, and we investigated them for the first time in acupuncture research within this study. Both parameters have been alleged to reflect changes in the clinical state of sedation. Two different acupuncture schemes were tested in a randomized crossover trial with nine healthy volunteers (mean age +/- sd, 28.8 +/- 3.6 yr; 25-36 yr). Applying and stimulating acupuncture needles or performing laserneedle acupuncture at special sedation points decreased RE and SE significantly (P < or = 0.01; paired t-test) compared with the reference interval before acupuncture. In contrast, acupuncture of points for increasing "Qi-energy" did not decrease parameters of entropy. Specific acupuncture schemes produce specific, reproducible, and quantifiable effects on entropy parameters in the EEG. Therefore, entropy measurements during acupuncture seem to be worthy of further evaluation with a larger series of subjects.
authors.affiliation: Research Unit of Biomedical Engineering in Anesthesia and Intensive Care Medicine, Medical University of Graz, Graz, Austria. gerhard.litscher@meduni-graz.at
authors.forename: Gerhard
authors.initials: G
authors.lastname: Litscher
mesh_terms: D015669:Acupuncture Points; D015670:Acupuncture Therapy; D000328:Adult; D016292:Procedural Sedation; D018592:Cross-Over Studies; D004569:Electroencephalography; D019277:Entropy; D006801:Humans; D007834:Lasers; D009339:Needles; D012815:Signal Processing, Computer-Assisted