Clinical Evaluation of Small Vestibular Schwannoma

Abstract

BACKGROUND AND OBJECTIVES: It is not easy to detect the small-sized vestibular schwannomas because they sometimes show atypical clinical presentation such as sudden deafness and detection by chance. However, it is very important to diagnose a vestibular schwannoma in the earlier stage to preserve facial nerve function and hearing. This study aimed to analyze clinical characteristics of small vestibular schwannomas and to make decision analysis of their diagnostic work-up. MATERIALS AND METHOD: we reviewed retrospectively 42 patients who were diagnosed with vestibular schwannoma of size less than 1.5cm at the Departments of Otolaryngology, Ajou University Hospital and Yonsei University Hospital from June, 1994 to May, 2002. This study analyzed chief complaints, size of tumor, audiological studies, caloric test, imaging study, and treatment modality. RESULT: Sixteen of 42 patients (38.1%) were in group IC , 20 patients (47.6%) for group 0 and 6 patients (14.3%) for group 1. One third of cases presented initial symptoms such as sudden hearing loss, the other third presented tinnitus, and 4 cases were detected by chance. Fourteen cases showed near normal hearing and auditory brainstem response (ABR) showed 76.2% sensitivity, which was relatively lower than we expected. CONCLUSION: Because acoustic neuroma was suspected in patients with unilateral hearing loss, tinnitus, and dizziness were very important considerations. We made the decision analysis in the diagnosis of small vestibular schwannoma. It consisted of earlier intervention of fast spin echo magnetic resonance imaging (MRI) based on a cost-effective approach.