[Idiopathic sudden sensorineural hearing loss: a review].
Idiopathic Sudden Sensorineural Hearing Loss (ISSHL) remains one of the major unsolved otologic emergencies. It is characterized by the onset of an unilateral sensorineural hearing loss developing within 24 hours, and averaging on pure tone audiogram at least 30 dB HL for three subsequent octave steps, with no marked vestibular symptoms and no identifiable cause. ISSHL is a syndrome covering several heterogeneous entities resulting from different pathogenetic mechanisms. At this time, the audiogram is the unique tool which may help clinicians to identify these entities and provide a classification based on 5 types of hearing loss. Numerous experimental and clinical studies have investigated the mechanisms by which infectious, ischemic, mechanic or immunologic insults may induce cochlear dysfunction. However, extrapolation to humans and rationale therapeutic approaches to ISSHL remain uncertain. SSHL being a diagnosis of exclusion, retrocochlear and neurologic etiologies should be eliminated. No argument allows to consider ISSHL a therapeutic emergency. More precisely, the experimental data presently available on cochlear physiology suggests that a treatment could have some chance to be effective if undertaken within minutes following the onset of ISSHL, a condition never encountered in daily practice. Conversely, it is not justifiable to impute the absence of hearing recovery to a delay in therapy. The various therapeutic strategies currently recommended are highly empirical and should be questionned in terms of cost-effectiveness, the most common being high-dose corticosteroids. New investigation tests are required for improving our approach to ISSHL.
Charrier
J-B
JB
Service d'ORL et de chirurgie de la face et du cou, Assistance Publique-Hôpitaux de Paris, Université Paris VII Hôpital Lariboisière 2, rue Ambroise Paré 75010 Paris, France.
Tran Ba Huy
P
P
D003937:Diagnosis, Differential; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000209:etiology / Q000628:therapy; D006801:Humans; D011379:Prognosis