VASCULAR-DECOMPRESSION SURGERY FOR SEVERE TINNITUS

Vascular compression of the eighth cranial nerve is increasingly recog nised as a possible cause of incapacitating audiovestibular symptoms. There have been few reports of the efficacy of surgical microvascular decompression for tinnitus, and the practise is controversial. During the last 6 years, investigation by air computed tomography (CT) cister nography initially, and fast spin-echo magnetic resonance imaging (MRI ) latterly has resulted in the diagnosis of cochlear nerve vascular co mpression in nine patients with a primary complaint of severe tinnitus who have subsequently undergone vascular-decompression surgery. The d uration of symptoms ranged between 1 and 10 years, whilst their subjec tive tinnitus perception varied between 30 to 60 dB above threshold. M icrovascular decompression was carried out by a retrolabyrinthine appr oach in four and by a retrosigmoid approach in the remaining five case s, with a postoperative follow-up of 1.3 to 5 years. Tinnitus was comp letely abolished in three (33%), very significantly improved to a sens ation level of less than or equal to 10 dB in four (33%), significantl y improved to a level of 15 dB in one (11%), and unchanged in two (22% ). Both failures had had tinnitus for 6 years and had transient abolit ion for 10 days after surgery. Subsequent revision decompression surge ry was also unsuccessful. This small study suggests that cochleovestib ular vascular compression may result in severe tinnitus, which can oft en be ameliorated surgically.