BOTULINUM TOXIN VERSUS TRIHEXYPHENIDYL IN CERVICAL DYSTONI - A PROSPECTIVE, RANDOMIZED, DOUBLE-BLIND CONTROLLED TRIAL

Background: Botulinum toxin type A (BTA) is replacing trihexyphenidyl as the treatment of choice for idiopathic cervical dystonia (ICD), but there has never been a direct comparative study. Methods: This trial compares the effectiveness of BTA with that of trihexyphenidyl in a pr ospective, randomized, double-blind design. Sixty-six consecutive pati ents with ICD were randomized to treatment with trihexyphenidyl tablet s plus placebo injection or placebo tablets plus BTA injections. Table ts were administered daily according to a fu:ed schedule. Dysport or s aline was injected under EMG guidance at study entry and again after 8 weeks. Patients were assessed for efficacy at baseline and after 12 w eeks by different clinical rating scales. Results: Sixty-four patients completed the study, 32 in each group. Mean dose of BTA was 292 mouse units (first session) and 262 mouse units (second session). Mean dose of trihexyphenidyl was 16.25 mg. The changes on the Disability sectio n of the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS-Di sability) (primary outcome), Tsui Scale, and the General Health Percep tion Subscale were significantly in favor of BTA. More patients treate d with BTA had an improvement of at least three points on the TWSTRS-D isability (14 versus 6) and on the Tsui Scale (23 versus 12). Adverse effects were significantly less frequent in the BTA group. Conclusion: BTA is significantly more effective in the treatment of ICD, with les s adverse effects.