Auditory and electrophysiological patterns of a unilateral lesion of the lateral lemniscus.
Auditory disorders resulting from focal brainstem lesions are rarely symptomatic. Isolated lesions of the inferior colliculus have previously been reported, whereas no detailed description of a localized involvement of the lateral lemniscus is yet available. We report a unilateral lesion of the lateral lemniscus by a bleeding in a cavernoma. Symptoms included strictly contralateral tinnitus and auditory impairment, with normal pure-tone and speech audiometry. Conversely, the dichotic listening test revealed an extinction of contralateral ear input. The brainstem auditory evoked potentials disclosed a reduced and delayed wave V only after contralateral ear stimulation, while the middle latency evoked potentials were normal. This observation shows that a unilateral lesion of the lateral lemniscus can produce auditory symptoms. The dysfunction of auditory pathways is associated with specific electrophysiological abnormalities that can be assessed by evoked potential recording.
Cho
Tae-Hee
TH
Department of Clinical Neurophysiology and UCB EA1880, Hôpital Neurologique et Neurochirurgical, Lyon, France.
Fischer
Catherine
C
Nighoghossian
Norbert
N
Hermier
Marc
M
Sindou
Marc
M
Mauguière
François
F
D000328:Adult; D001299:Audiometry; D001306:Auditory Pathways / Q000098:blood supply / Q000503:physiopathology; D001933:Brain Stem / Q000098:blood supply / Q000503:physiopathology*; D002543:Cerebral Hemorrhage / Q000150:complications*; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D007839:Functional Laterality; D046088:Hearing Loss, Unilateral / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D014012:Tinnitus / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology