Summary:Objective quantification of the symptoms of Meige's syndrome is difficult and has not been performed in the majority of pharmacological studies of Meige's syndrome published so far. The aim of the present study was to reexamine the therapeutic potential of biperiden, clonazepam, haloperidol, and lisuride using an objective method of quantification of the symptoms. Eleven patients received daily i.v. injections of biperiden, 5.0 mg; clonazepam, 1.0 mg; haloperidol, 2.5 mg; lisuride, 0.05 mg; and placebo in randomized order. The symptoms of the patients [idiopathic blepharospasm (IB), in 11 patients, oromandibular dystonia (OMD) in four patients] were quantified by a blind observer counting the frequencies and recording the cumulative duration of sustained spasms of IB and OMD over periods of 4 min before, and 15, 30, 60, 90, and 120 min after the i.v. challenges. Baseline quantification of IB and OMD was performed at identical intervals on randomized days of the trial. Significant improvement of the IB scores was found in response to biperiden and clonazepam and a trend toward improvement in response to lisuride (Wilcoxon test). Evaluation of the individual IB scores of each patient following the various drug challenges failed to predict the therapeutic potential of these drugs for subsequent oral treatment.