[Vestibular schwannoma: Part I: epidemiology and diagnostics].

Vestibular schwannoma is with 80% the most frequent of all tumors of the cerebellopontine angle. Usually, this benign, neuroectodermal, mostly unilateral occurring tumor is called acoustic neuroma, although it develops from the Schwann cells of the nerve sheath of the eighth cranial nerve. The tumor is localized in the meatus acusticus internus in the majority of cases. The most common initial symptom is a unilateral or, at least, asymmetric hearing loss. Other symptoms may include tinnitus and feeling of insecurity or vertigo, but adjacent cranial nerves may also be affected. Besides clinical and apparatus-based (neuro-)otological diagnostics, MRI imaging has established itself as the gold standard with a sensitivity and specificity of up to 100%.