Brainstem auditory evoked potentials in Wilson's disease.

Twelve patients with Wilson's disease, aged 11-25 years, underwent brainstem auditory evoked potential (BAEP) study. The results were correlated to clinical, neuroradiological and laboratory data. Ten had prominent to severe neurological manifestations, suggestive of involvement of one or several CNS structures, and 2 were neurologically free. All had evidence of abnormal copper metabolism, and 8 had CT scan evidence of brain atrophy, or hypodense areas in basal ganglia, or both. The 2 patients without neurological manifestations as well as one with neurological signs had normal BAEP. One patient with neurological signs had increased N1 latency due to cochlear hearing loss, but normal interpeak intervals, while 8 of 10 patients with prominent neurological symptoms and signs had abnormal BAEPs (prolongation of NIII-NV interpeak interval). The value of NIII-NV interpeak interval correlated with the number of different neurological signs (neurological score) attributable to involvement of different CNS structures (r = 0.64 at P = 0.001). Abnormal BAEPs do not seem to be an early finding in Wilson's disease.