Clinical observations on coexistence of sudden hearing loss and vestibular schwannoma.

It has long been recognized that sudden hearing loss (SHL) may be a harbinger of vestibular schwannoma (VS). Among 192 VS patients who underwent operation in the Gruppo Otologico, Piacenza, Italy, from April 1987 to October 1995, the charts of 14 (7.3%) cases with a history of SHL were examined. SHL was the first symptom in 8 (4.2%) patients. Eight (57.1%) of 14 VS cases with SHL anamnesis had reported recovery of their previous hearing either totally or partially before establishment of tumor diagnosis. Five (35.7%) cases had recurrent bouts of SHL. SHL was observed less frequently in cases with large tumors (>3 cm). However, the frequency of SHL in patients with small tumors did not differ from that of medium-sized tumors. Awareness about coexistence of SHL and VS, as well as concomitant use of auditory brain stem response and magnetic resonance imaging, is crucial to rule out the diagnosis of VS in a patient with SHL.