Author/Editor		Butinar, Dušan; Starr, Arnold
Title		Diagnostic strategy in patients with auditory neuropathy associated with HMSN type I
Type		članek
Source		In: Hashimoto I, Kakigi R, editors. Recent advances in human neurophysiology. Proceedings of the 6th international evoked potentials symposium; 1998 Mar 21-25; Okazaki, Japan. Amsterdam: Elsevier science,
Publication year		1998
Volume		str. 872-8
Language		eng
Abstract		Background. The goal of this work was to assess the auditory system in patients with an hearing impairment due to auditpry neuropathy. The patients presened with a distinct clinical syndrome with: 1) elevation of pure tone thresholds in the presence of preserved outer hair cell function as suggested by otoacoustic emission, 2) absent or markedly abnormal brainstem auditory evoked potentials (BAEPs), 3) elevation of speech perception out of proportion to the pure tone loss, and 4) other test results that distinguish them from patients with hearing loss due to cochlear damage. Patients. We examined 28 members of a gypsy family, with two siblings age 31 and 30 years, and one, age 20 years, suffering from HMSN type I associated with auditory neuropathy. The two siblings with marked difficulty of understanding speech had undergone the following investigations: pure tone and speech audiograms, BAEPs, cochlear microphonics, otoacoustic emission (OAEs), nerve conduction studies (NCV), caloric tests and somatosensory evoked potentials (SEPs). Results. Both siblings had a flat 80 dB HL audiogram, no speech comprehension, and absent BAEPs. One of them had preserved cochlear microphonics on the right ear and both had OAEs. Peripheral nerves were electrically nonelicitable, however, at the beginning of the disease they were very slow. Both of them had no vestibular caloric responses, and absent SEPs. Conclusion. In two patients with a distinct clinical picture of HMSN type I we proved that the hearing impairment they had was due to severe demyelination of the cochlear nerve in the presence of preserved inner ear function.
Descriptors		CHARCOT-MARIE DISEASE EVOKED POTENTIALS, SOMATOSENSORY AUDIOMETRY, EVOKED RESPONSE AUDIOMETRY, PURE-TONE EVOKED POTENTIALS, AUDITORY, BRAIN STEM AUDIOMETRY, SPEECH NEURAL CONDUCTION CALORIC TESTS PEDIGREE