BAEPs in hereditary motor-sensory neuropathies. Involvement of central brain-stem parts of the auditory pathway.

Brain-stem auditory evoked potentials (BAEPs) were tested in 34 patients with hereditary motor and sensory neuropathy (HMSN), most of which with HMSN type I with the autosomal dominant type of inheritance. In only a few cases a recessive or sporadic form of the disease was diagnosed, and one patient was rated as HMSN type III. In 44% complicated forms with signs of CNS involvement (cerebellar manifestation, nystagmus or cranial nerve lesions) were ascertained. BAEPs tests revealed slightly, albeit non-significantly prolonged wave III latency while wave V latency was significantly prolonged and so was the interpeak interval of waves III-V. One third of the records showed a prominent decrease in wave V amplitude.