[Are we sectioning the cochlear efferent system during vestibular neurotomy?].
BACKGROUND
In addition to sensory neurons which transmit information from the inner ear to the brain, there is a system of efferent feedback fibers, called the olivocochlear system, carrying signals from the brain to the ear. Over the past half-century, the efferent system has been extensively studied in animals and results provided theories as to the functional significance of these efferents: to improve signal-to-noise ratio in the auditory periphery, to mediate selective attention, and to protect the inner ear from acoustic overexposure. The results of several studies conducted in man rely on the study of patients who have undergone a vestibular neurectomy. Indeed, anatomical data show that olivocochlear efferents could travel along or inside the vestibular part of the auditory nerve before reaching the organ of Corti. Therefore, these patients may be considered as an experimental model of unilaterally de-efferented subjects. However, to date, none has reported the existence of olivocohlear efferents in the vestibular section following neurectomy.


RESULTS
In this study, we present the histological results from 18 vestibular sections and show the absence of olivocochlear efferents.


CONCLUSIONS
These results provide a reason to reconsider the results of previous experiments conducted in similar patients and ask for further studies on the olivocochlear efferents pathways.
Chays
A
A
Hôpital Robert Debré, Service d'Oto-Rhino-Laryngologie et de Chirurgie Cervico-Faciale, Avenue du Général Koenig, F-51092 Reims, France. a.chays@wanadoo.fr
Maison
S
S
Robaglia-Schlupp
A
A
Cau
P
P
Broder
L
L
Magnan
J
J
D003051:Cochlea / Q000601:surgery*; D046508:Culture Techniques; D006801:Humans; D009434:Neural Pathways / Q000502:physiology; D009464:Neuroma, Acoustic / Q000473:pathology / Q000601:surgery*; D009476:Neurons, Efferent / Q000502:physiology*; D009925:Organ of Corti / Q000033:anatomy & histology / Q000502:physiology; D013506:Otologic Surgical Procedures / Q000379:methods*; D014725:Vestibular Nerve / Q000473:pathology / Q000601:surgery*; D000160:Vestibulocochlear Nerve Diseases / Q000473:pathology / Q000601:surgery*