[Neurofibromatosis type 2--initial symptoms and diagnostic problems].

The presenting symptoms in a group of 16 NF2 patients treated in neurosurgical tertiary referral centers are reviewed. Eight of the cases are distinct severe forms (Wishart type) and one demonstrated a mild disease course (Gardner type). Fourteen cases represent new mutations. The mean age of onset was 17.88 years. Twenty-five percent of the cases initially fulfill the established diagnostic criteria. More than a half of the patients presented initial symptoms related to tumors other than vestibular schwannomas. The mean interval between the age of onset and the age at diagnosis was 7.19 years. The reasons of the delay are discussed.