Effects of sensory stimulation on level of consciousness in comatose patients after traumatic brain injury: A systematic review

BACKGROUND: A coma is a prolonged unconscious state in which there is no response to various stimuli. In response, sensory stimulation was designed to stimulate brain plasticity and to promote brain regeneration. The effects of sensory stimulation intervention on comatose patients following traumatic brain injury (TBI) remain unclear. OBJECTIVES: This study aimed to examine the effects of sensory stimulation on the level of consciousness (LOC) after TBI and to identify the effective treatment dosage. METHODS: We searched PubMed, REHABDATA, EMBASE, CINAHL, MEDLINE, PEDro, SCOPUS, and Web of Science from inception to February 2020. Experimental studies investigating the influence of sensory stimulation on the LOC in the comatose patients (Glasgow coma scale < 8) following TBI were selected. The Physiotherapy Evidence Database scale (PEDro) was used to evaluate the methodological quality. RESULTS: Eleven studies met the inclusion criteria. Six were randomized controlled trials (RCTs), clinical controlled trials (CCTs) (n = 2), and pilot studies (n = 3). A total of 356 comatose patients (<8 on GCS) post-TBI were included in this study with sample sizes ranging from 5–90 patients. The sample sizes for the selected studies ranged from 5 to 90 patients. The scores on the PEDro scale ranged from three to eight, with a median score of seven. The multimodal sensory stimulation showed beneficial effects on the LOC in the comatose patients following TBI. The evidence for the effects of unimodal stimulation was limited, while the optimal treatment dosage remains unclear. CONCLUSIONS: The multimodal sensory stimulation intervention improves the LOC in patients with coma after TBI compared with unimodal stimulation. Further high-quality studies are needed to verify these findings.