[Neurofibromatosis type 2]

To investigate the clinical characteristics and management strategies of bilateral acoustic neuromas.

The data of 7 patients with bilateral acoustic neuromas collected between 1990 to 1998 were retrospectively analyzed.

Altogether 122 patients with acoustic tumors were treated from 1990 to 1998, in which 7 cases (5.8%, 6 male and 1 female) had bilateral acoustic neuromas. The age at onset of symptoms ranged from 13 to 60 years (average 29.1 years). Progressive hearing loss and tinnitus were the initial symptoms in 4 cases. Either strabismus, ptosis, headache or dysequilibrium was presented in 4 cases. Six cases complicated tumors in the central nervous system and/or other sites. Five cases had cafe au lait spots. One case had posterior subcapsular lenticular opacity. Four cases fell into severe (Wishart) type and 2 into mild (Gardner) type. The tumors were unilaterally removed in 4 patients through the retrolabyrinthine approach (1 case) or the retrosigmoid approach (3 cases). In these 4 patients, one died of central respiratory failure after the operation; two had contralateral tumor removal through retrosigmoid approach 3 weeks after the first surgery. One of the patients died of encephaledema after the surgery. No hearing impairment and facial nerve paralysis occurred in one case operated on through the retrolabyrinthine approach, whereas in those through retrosigmoid approach, 4 ears had hearing loss and 3 sides had facial nerve paralysis.

The clinical characteristics and treatment strategies for bilateral acoustic neuromas are different from those of unilateral acoustic neuroma. Individualization of management is a prerequisite for the success of the treatment. To avoid injury to the VII and VIII cranial nerves, monitoring the nerve functions during the surgery is important.