MANAGEMENT OF 1000 VESTIBULAR SCHWANNOMAS (ACOUSTIC NEUROMAS) - CLINICAL PRESENTATION

OBJECTIVE: Despite good knowledge of the key symptoms of vestibular sc hwannomas and their significance for surgical results, the evolution o f symptoms and signs and their relation to tumor extension stilt need thorough investigation. METHODS: From 1978 to 1993, operations were pe rformed by the same surgeon (M.S.) on 1000 vestibular schwannomas at t he Neurosurgical Department of Nordstadt Hospital, The vestibular schw annomas were diagnosed in 962 patients, including 522 female patients (54%) and 440 male patients (46%); the mean age was significantly high er in female patients (47.6 yr) than in men (45.2 yr). We focused our analysis on the incidence of subjective disturbances versus objective morbidity, on the sequence of symptom onset, and on symptom duration a nd symptomatology versus tumor size and extension. RESULTS: The most f requent clinical symptoms were disturbances of the acoustic (95%), ves tibular (61%), trigeminal (9%), and facial (6%) nerves. Symptom durati on was 3.7 years for hearing loss, 1.9 years for facial paresis, and 1 .3 years for trigeminal disturbances. Symptom incidence and duration d id not strictly correlate with tumor size. Key symptoms of various tum or extension classes precipitated the diagnosis, such as trigeminal di sturbances in large tumors with brain stem compression or tinnitus in smalt neuromas. In cases of trigeminal or facial nerve symptoms, the o verall duration of symptomatology was much shorter. According to the s ubjective perception of the patients, between only one- and two-thirds of nerve disturbances were noticed. Patients with preoperative deafne ss had become deaf either chronically (23%) or suddenly (3%); even in cases of moderate hearing deficit that lasts a long time, deafness can occur suddenly. The rate of tinnitus was higher in hearing than in de af patients; however, deafness does not mean relief from tinnitus, bec ause this symptom persists in 46% of preoperatively deaf patients. Ves tibular disturbances most often occur as some unsteadiness while walki ng or as vertigo, and the symptoms frequently are fluctuating, not con stant. CONCLUSION: Differences in tumor biology can be underestimated and are not visible on radiological scans. For example, intrameatal tu mors, despite their small size, present with a duration of symptoms th at is representative of the larger tumors and are most frequently asso ciated with vestibular symptoms and with tinnitus. Large tumors with b rain stem compression present with relatively shorter symptom duration s and at a younger age; both factors are suggestive of especially fast tumor growth. The clinical findings presented in this study promote n ew consideration of the dynamics of tumor growth and of the affected n eural tissues.