Correlation of brain stem evoked response audiometry (BERA) with Glasgow Coma Scale (GCS) and Glasgow Outcome Scale (GOS)

The diagnostic value of electric responses from the brain stem (BERA) in neurosurgical patients is still a matter for debate in the literature. Therefore in the study an attempt was made to determine the relationship between GCS scores and BERA recordings. Participants in the study were 64 patients with various types of brain damage. Evoked potentials from the brain stem were registered using the Hortmann BERAmodul apparatus. To facilitate the interpretation of results a special scale was developed for quantitative measurement of changes in BERA recordings. Abnormalities in BERA recordings were reflected in changes in GCS scores, and correlation between the two dimensions was found to be statistically significant. The relationship between BERA recordings and GOS scores was also significant: pathological changes in BERA recordings assessed as severe were associated with an unfavorable therapeutic outcome in the GOS. The presented findings indicate auditory evoked brain stem response (BERA) usefulness for objective evaluation of brain-damaged patients' clinical state.