Auditory brainstem response audiometry in neonatal hydrocephalus.

Sixteen hydrocephalic NICU babies and 16 age-matched, non-hydrocephalic NICU babies were tested with BERA. The latency and amplitude of waves I and V were compared between groups. Both waves were longer in latency and smaller in amplitude in the hydrocephalic group. The I-V latency interval was within normal limits, but the V/I amplitude ratio was significantly smaller. The reduced amplitude of wave V was the most noticeable ABR abnormality. A total of 11 hydrocephalic babies showed responses that were considered abnormal in amplitude, with all but one having an elevated ABR threshold in at least one ear. These threshold elevations may reflect a neurological condition rather than a peripheral hearing loss.