Placebo effect in surgery for Meniere's disease. A double-blind, placebo-controlled study on endolymphatic sac shunt surgery
J. Thomsen, P. Bretlau, M. Tos and N. J. Johnsen
To investigate the placebo effect in surgery for Meniere's disease, a
double-blind controlled study was undertaken, comparing effects of a
regular endolymphatic shunt with those of regular mastoidectomy. Thirty
patients with typical Meniere's diseases, selected because of unsuccessful
medical treatment, participated. Patients completed daily dizziness
questionnaires three months before and 12 months after surgery, with
registration of nausea, vomiting, vertigo, tinnitus, hearing impairment,
and pressure in the ears. Patients were operated on at two universities,
and the patients operated on at one underwent controlled study each month
at the other. At termination of the trial, both investigators and patients
gave their opinions of the efficacy of the operations. Minor differences
were seen between active and placebo groups, but the greatest difference in
symptoms was found when preoperative and postoperative scores were
compared: both groups improved significantly
