[Effect of microneurosurgical operation in acoustic neurinoma on symptoms of vertigo and tinnitus].

After exstirpation of an acoustic neuroma one trends to concentrated on the preservation of hearing and facial function. But how does the surgical removal for an acoustic neuroma, influence the symptoms of tinnitus and vertigo? Our report follows a retrospective evaluation of 78 patients. Based on these results we will also discuss aspects of the origin of these symptoms. Our patients suffered from tinnitus at a rate of 73% preoperatively and 59% postoperatively. With increasing tumor size tinnitus occurred less often, therefore we considered the size of the tumor exclusively. Also, an intraoperative dissection of the cochlear nerve often did not result in an improvement of the symptoms. Vertigo was stated prooperatively in 44% of the cases, postoperatively in 22%. Again as with tinnitus, there was an inverse relationship between the size of the tumor and the severity of the symptoms. In conclusion a deafferention-like syndrome has to be considered as the major causative factor for the tinnitus in patients with acoustic neuromas. However, in the vertigo cases, the symptoms seem to be caused vestibularily due to the increasing tumor and then after a temporary compensation a cerebellar ataxia occurred which the patients often perceive as vertigo.