Sudden sensorineural hearing loss (SSHL) is a frequent symptom of vestibular schwannoma
(VS), often reveals small VSs and does not exhibit specific features. Therefore, every
case of SSHL should be evaluated using systematic MRI to rule out VS in order to improve
hearing and preservation facial nerve function. SSHL leads to the discovery of a VS
in a small proportion of cases (2%). However, SSHL appears to be a more frequent occurrence
in the history of patients with VS (3-23% in the literature), suggesting a large disparity
in the evaluation of SSHL. A total of 139 consecutive unilateral VSs operated on between
2000 and 2002 were reviewed and analyzed regarding the prevalence, clinical and audiological
features of SSHL and their relation to the size of the tumor. SSHL was observed in
20% of cases at some point in their VS history. The characteristics of SSHL were:
(i) lack of a specific audiometric pattern, except that low-tone loss was rare; and
(ii) a high rate of hearing recovery (50%). Tumor size was significantly smaller in
SSHL-associated VSs compared to other VSs. In the former cases, 96% involved the internal
auditory canal.
