Transcutaneous auricular vague nerve stimulation improved brain connection activity on patients of disorders of consciousness: a pilot study

OBJECTIVE: To evaluate the clinical effect of transcutaneous auricular vagus nerve nerve stimulation (taVNS) on disorders of consciousness (DOC) patients with Coma Recovery Scale-Revised (CRS-R) and cerebral cortex activity by electroencephalogram (EEG) detection. METHODS: Randomized controlled methods were used to evaluate the clinical effect of taVNS on patients with DOC. Twelve patients with initial CRS-R of 6-10 were randomly divided into the treatment group of taVNS and control group of transcutaneous non-auricular vague nerve stimulation (tnVNS). According to clinical diagnosis, the treatment group was divided into vegetative state (VS) group and minimally conscious state (MCS) group. RESULTS: The energy of delta and beta bands is positively correlated with the brain activity of patients. taVNS has different regulatory effects on patients with different conscious States. In taVNS group, the energy of delta band in local brain regions changed significantly. Significant changes in brain connection activity were limited to local brain regions. While in patients with MCS in the taVNS group, delta and beta band energy significantly changed in multiple brain regions and cross-brain connection activity also changed significantly. CONCLUSION: These findings suggest that taVNS may be a related extra method for arousing patients' awakening by improving brain connection activity. And the effect is remarkable in MCS patients.