Persistent absence of auditory brainstem responses with preserved hearing and recovery from a prolonged comatose state

Abstract

A patient with hypertensive intracerebellar haemorrhage, who recovered from impending tonsillar herniation with emergency haematoma evacuation, showed persistent absence of auditory brainstem responses. The patient demonstrated a preserved stapedius reflex and hearing after recovery, indicating that the auditory brainstem pathway was not completely disrupted. We suggest that the loss of the auditory brainstem response (ABR) could be accounted for by impulse asynchrony along the auditory brainstem pathway. The existence of such a case implies that persistent absence of the ABR is not always indicative of irreversible brainstem damage and a poor outcome following severe brain injury.