Acute Traumatic Coma Awakening Induced by Median Nerve Electrical Stimulation: A Systematic Review and Meta-Analysis

Traumatic brain injury (TBI) is widely recognized as a major cause of death and disability. Optimizing recovery from coma is a priority for improving patient prognosis. Recently, an increasing number of studies have demonstrated that median nerve electrical stimulation (MNES) may be a potential approach for comatose patients awakening with TBI, although the results of these studies are not consistent. The aim of this study was to evaluate the effects of the MNES on recovery from coma in patients with TBI based on data from randomized controlled trials. The PubMed, Embase, Ovid MEDLINE, Cochrane Library, and China National Knowledge Infrastructure electronic databases were systematically searched from their inception to July 2023 using specific keywords. The χ² test and I² test were used to evaluate the heterogeneity across these studies. The mean differences with 95% confidence intervals (CIs) and relative risk (RR) with 95% CIs were adopted to analyze the continuous outcomes and binary outcomes, respectively. A total of 1831 patients from 18 studies were included in this meta-analysis. There were significant differences in the proportions of patients who regained consciousness between the MNES group and the control group after treatment (RR 1.36, 95% CI 1.18-1.56; P < 0.001) and at 6 months after injury (RR 1.31, 95% CI 1.16-1.47; P < 0.001). MNES significantly improved the Glasgow Coma Scale score (mean difference 2.38, 95% CI 1.78-2.98; P < 0.001). Furthermore, no significant differences in complications between the two groups of patients were observed, including pneumonitis (RR 0.86, 95% CI 0.72-1.03; P = 0.107), seizures (RR 1.24, 95% CI 0.49-3.10; P = 0.651), or gastric hemorrhage (RR 1.08, 95% CI 0.60-1.93; P = 0.795).The results of the present study indicate that patients with TBI in the MNES group recovered from coma more rapidly after treatment and at 6 months after injury. These results suggest that MNES is an effective approach for coma awakening after TBI.