Microvascular decompression of the vestibulocochlear nerve for disabling positional vertigo: The house ear clinic experience

Objective: To review characteristics of and outcome in patients undergoing microvascular decompression of the vestibulocochlear nerve. Patients studie d had a diagnosis of disabling positional vertigo caused by a vascular loop compressing the VIIIth cranial nerve. Study Design: Retrospective chart review and telephone interview. Setting: Private practice tertiary neurotologic referral center. Patients: Twenty patients with disabling positional vertigo underwent 25 re trosigmoid craniotomies for microvascular decompression between November 19 90 and June 1999. The 4 men and 16 women ranged in age from 30 to 71 years (mean age, 46 yr). Main Outcome Measures: Charts were reviewed and patients were contacted by telephone and asked to rate severity of symptoms (tinnitus and dizziness) o n a 4-point scale (none = 1, mild = 2, moderate = 3, and severe = 4) before and after surgery. They were also asked to rate their overall disability f rom their symptoms on the six-point scale established by the American Acade my of Otolaryngology-Head and Neck Surgery. Preoperative and postoperative four-frequency (500 Hz, 1 kHz, 2 kHz, and 4 kHz) pure-tone average and spee ch discrimination scores were calculated and compared. Complications of sur gery are also reported. Results: Postoperative tinnitus score and dizziness score showed significan t improvement from preoperative scores (p less than or equal to 0.047 and p less than or equal to 0.001, respectively). with 80% of patients improved in dizziness rating: 85% improved in their overall disability rating, and t he difference from preoperative to postoperative was significant (p less th an or equal to 0.001). The mean postoperative pure-tone averages ( 15.4 dB) and speech discrimination scores (99%) did not differ from preoperative sc ores ( 11.9 dB and 98%). One patient lost all vestibular function in the op erated ear (hearing remained intact) as the only complication of surgery. W hen asked, 83% of patients responded that they would have the surgery again . Conclusions: Diagnosing disabling positional vertigo secondary to vascular compression of the VIIIth cranial nerve remains the clinical challenged a c lear history Plus air-contrast computed tomographic or magnetic resonance i maging make the diagnosis. Microvascular decompression of the vestibulococh lear nerve is a safe and effective operation for these carefully selected p atients.