Ménière's disease: endolymphatic sac decompression compared with sham (placebo) decompression.

The placebo effect in surgery for Ménière's disease was investigated in a double-blind, controlled surgery by comparing the effect of a regular endolymphatic shunt with the effect of a purely placebo operation (regular mastoidectomy). Thirty patients with typical Ménière's disease participated in the study. They were selected for surgery because of unsuccessful medical treatment and were chosen randomly for each treatment group. The patients filled in daily dizziness questionnaires for 3 months before and 12 months after surgery, registering nausea, vomiting, vertigo, tinnitus, hearing impairment, and pressure in the ears. The patients were operated on in two university ENT departments. Those operated on in one department were controlled each month at the other department, and vice versa. At the termination of the trial, the investigators as well as the patients gave their overall opinion of the efficacy of the operation. Minor differences could be demonstrated between the active and the placebo group, but the greatest difference in symptoms was found when comparing pre- and postoperative scores, in which both groups improved significantly.