Auditory and somatosensory evoked potentials in coma following spontaneous cerebral hemorrhage: early prognosis and outcome

The aim of this study was to check the prognostic power of auditory brain-stem responses (ABRs) and somatosensory evoked potentials (SEPs) in coma following spontaneous cerebral hemorrhage. Seventy patients comatose following subarachnoidal or hypertensive hemorrhage were submitted to ABR and SEP recordings during the acute phase of clinical course. Twenty-one patients survived (30%), two remained vegetative (2.9%) and 47 died (68.1%). The Glasgow Coma Score (GCS) was significantly related to the outcome (P<0.001), but showed a low sensitivity, about 50% of patients with GCS=5–8 died or remained vegetative. ABRs and SEPs showed a much closer correlation with outcome (P<0.001): their combined use allowed there to be a sensitivity of 96%, a specificity of 90% and a predictive power of 96%; the relative risk of poor outcome in patients with at least one abnormal modality was equal to 223 times the one for patients with normal evoked potentials. Moreover, in surviving patients a significant relationship appeared to exist between abnormalities of SEPs during the acute phase and the severity of disability. Our results confirm the prognostic effectiveness of short latency evoked potentials in cerebral hemorrhage: they are far superior to clinical data, being able to yield a marked decrease of falsely optimistic predictions.