Otoacoustic emission in myasthenia gravis patients and the role of efferent activation.
Hear Res
; 126(1-2): 123-5, 1998 Dec.
Article
en En
| MEDLINE
| ID: mdl-9872140
ABSTRACT
We performed transient evoked otoacoustic emission (TEOAE) measurements on 29 ears of myasthenia gravis (MG) patients. The purpose of the study was to support the role of acetylcholine (ACh) in the efferent innervation of cochlear outer hair cells (OHCs). Another aim was to establish additional diagnostic tools for the early determination of MG. Initially, threshold audiometry and impedance measurements showed normal values on the ears examined. The main finding was that TEOAE values were significantly lower in MG patients than in healthy controls. Mestinon, a reversible cholinesterase inhibitor, resulted in a significant increase in mean values of TEOAEs, although these values were still lower than normal. The results suggest that in MG, acetylcholine receptor (AChR) autoantibodies inhibit the function of OHC AChRs. Thus, the TEOAE generated by the active movements of OHCs is decreased in MG. Mestinon prevents the degradation of ACh, and thus stimulates efferent function and increases TEOAE values. The results obtained in this study support the role of ACh in the efferent function of OHC, as well as the impaired function of hair cell AChRs in MG patients. Consequently, measuring TEOAEs may be useful in the early diagnosis of some forms of MG. These results reinforce the importance of collaboration between neurologists and otolaryngologists in the management of diseases with pathological neurotransmission.
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Colección:
01-internacional
Asunto principal:
Inhibidores de la Colinesterasa
/
Emisiones Otoacústicas Espontáneas
/
Miastenia Gravis
Tipo de estudio:
Screening_studies
Límite:
Adult
/
Humans
Idioma:
En
Revista:
Hear Res
Año:
1998
Tipo del documento:
Article
País de afiliación:
Hungria