Abstract: ObjectiveTo study the value of brain stem auditory evoked potentials (BAEP) in evaluating the function of brainstem and judging the prognosis in patients with severe traumatic brain injury in vegetative state. Methods30 cases with severe traumatic brain injury in vegetative state were examined by BAEP and assessed with Glasgow Coma Scale (GCS) before comprehensive rehabilitation treatment and 1 month later. The patients were re-examined by BAEP and assessed with Glasgow Outcome Scale (GOS) after 6-month in follow-up. The relationship between BAEP grade and GCS or GOS was analyzed. The variety of BAEP in regaining consciousness was also analyzed.Results The abnormal rate of BAEP was 93.3% (28/30 cases) before rehabilitation treatment while it was 86.7% (26/30 cases) after 1 month. The higher the BAEP grade was, the poorer the prognosis was. There were 12 patients who regained consciousness.The main variety in these patients was the appearance of wave Ⅴ, as well as the improvement of each wave' shape and the shortening of peak latent period. ConclusionsBAEP can evaluate the function of brain stem in patients with severe traumatic brain injury in vegetative state and provide evidences for prognosis. The appearance of wave Ⅴ prompts the recovery of function of brain stem as an index of cerebral electrophysiology in improvement of consciousness.

Key words: brain stem auditory evoked potential, traumatic brain injury, vegetative state, evaluation, prognosis