The Effects of Acupuncture at Shuigou (GV26) on Patients With Disorders of Consciousness: An EEG Nonlinear Dynamics Analysis

Abstract

Background Disorders of consciousness (DOC) lack objective biomarkers. We evaluated the immediate cortical effects of acupuncture at Shuigou (GV26) in DOC patients using nonlinear EEG parameters: approximate entropy (ApEn), Lempel–Ziv complexity (LZC), correlation dimension ( D 2 ), and cross-approximate entropy (C-ApEn). Methods In a prospective study, 32 DOC patients (vegetative state/unresponsive wakefulness syndrome [VS/UWS], n = 17; MCS, n = 15) received 260-s manual acupuncture at GV26. Resting-state EEG was recorded pre- and postintervention. Nonlinear parameters were computed across 19 electrodes and compared between groups using independent/paired tests. Correlations with Coma Recovery Scale-Revised (CRS-R) scores were assessed via Spearman's analysis. Results Baseline ApEn, D 2 , and LZC were higher in minimally conscious state (MCS) than VS/UWS ( P < 0.05). Postacupuncture, ApEn increased in frontal, central, occipital (VS/UWS) and prefrontal, central, occipital, and temporal (MCS) regions ( P < 0.05). D 2 increased in all regions (VS/UWS) and occipital/temporal regions (MCS) ( P < 0.05). C-ApEn revealed enhanced connectivity, especially in VS/UWS. LZC showed no significant change. All parameters correlated positively with CRS-R; D 2 exhibited the strongest association ( r = 565–0.592, P < 0.01). Conclusion Acupuncture at GV26 acutely modulates cortical complexity and connectivity in DOC. D 2 and ApEn emerge as potentially sensitive markers of consciousness level and therapeutic response. Nonlinear EEG analysis offers a promising objective tool for evaluating neuromodulation in DOC.