The effectiveness of median nerve electrical stimulation in patients with disorders of consciousness: a systematic review

OBJECTIVE: To examine the effectiveness of median nerve electrical stimulation on consciousness level in subjects with disorders of consciousness.

METHODS: Electronic databases PubMed, EMBASE, CENTRAL, and PEDro, as well as manual search and gray literature were searched from inception until May 2019. We included only randomized controlled trials. Two reviewers independently conducted the search strategy, study selection, data extraction, risk of bias assessment, and evidence judgment quality.

RESULTS: Five studies met the inclusion criteria. Overall, no clear conclusion can be drawn about the intervention's effectiveness on the level of consciousness. One study reported a benefit of the intervention on the number of hospitalization days in the intensive care unit. Furthermore, another study reported a higher percentage of patients who regained consciousness six months from the event in the experimental group.

CONCLUSION: Due to the limited number of studies that met the inclusion criteria and overall high risk of bias, it is impossible to draw a definitive conclusion. The results of this systematic review should be used to improve future research in this field.