[A clinical study of 21 patients with neurofibromatosis I and II]

Neurofibromatosis (NF) 2, associated with bilateral acoustic neurinomas has been shown to be an entity distinct from NF 1, since their chromosomal abnormalities are completely different. NF 2 has a very low occurrence rate, but would be a terrible disease by its high prevalence of offsprings. In addition, compared to the majority of unilateral, nonfamiliar neurinoma, acoustic neurinomas of NF 2 have been shown to be refractory to treatments. Therefore, it is crucial to know the clinical characteristics of patients with NF 2. In this study, we analyzed 14 cases of NF 2 and 7 cases of NF 1 in whom brain tumors are main symptoms. Brain tumors associated with NF 1 were five neurinomas, two gliomas and a meningioma. The mean age of NF 1 patients accompanied with brain tumors was 37.6 years old, younger than the overall age of NF 1 patients. In patients with NF 2 there was often association with cranial, and spinal neurinomas and meningiomas. NF 2 especially, in younger patients was accompanied with multiple spinal neurinomas. Twenty acoustic neurinomas in 14 NF 2 patients were treated by surgery. Operative results showed that total resection was achieved in only 5 cases, 13 were subtotally and 2 were partially resected. Hearing preservation was attained in only three cases. In addition, all but two patients were complicated with postoperative facial palsy. From this analysis, it is clear that NF 2-associated acoustic neurinomas are not responsive to surgical intervention. We also reviewed genetical problems briefly.