Botulinum toxin versus trihexyphenidyl in cervical dystonia: a prospective, randomized, double-blind controlled trial. Mifepristone for the prevention of breakthrough bleeding in new starters of depo-medroxyprogesterone acetate. Efficacy and safety of a standardised 500 unit dose of Dysport (clostridium botulinum toxin type A haemaglutinin complex) in a heterogeneous cervical dystonia population: results of a prospective, multicentre, randomised, double-blind, placebo-controlled, parallel group study.
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.
                This trial compares the effectiveness of BTA with that of trihexyphenidyl in a prospective, randomized, double-blind design. Sixty-six consecutive patients with ICD were randomized to treatment with trihexyphenidyl tablets plus placebo injection or placebo tablets plus BTA injections. Tablets were administered daily according to a fixed schedule. Dysport or saline was injected under EMG guidance at study entry and again after 8 weeks. Patients were assessed for efficacy at baseline and after 12 weeks by different clinical rating scales.
                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 section of the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS-Disability) (primary outcome), Tsui Scale, and the General Health Perception Subscale were significantly in favor of BTA. More patients treated with BTA had an improvement of at least three points on the TWSTRS-Disability (14 versus 6) and on the Tsui Scale (23 versus 12). Adverse effects were significantly less frequent in the BTA group.
                BTA is significantly more effective in the treatment of ICD, with less adverse effects. Depo-medroxyprogesterone acetate (DMPA) is an effective injectable contraceptive with worldwide availability. However, it is associated with a high incidence of breakthrough bleeding (BTB) during the first 6 months of use which often leads to discontinuation. Mifepristone is a progesterone receptor antagonist that has been demonstrated to decrease BTB caused by the levonorgestrel subdermal implant (Norplant). The purpose of this study was to determine if mifepristone would decrease BTB in new starters of DMPA. Twenty regularly cycling women who were new starters of DMPA were randomized to receive 50 mg of mifepristone or placebo every 2 weeks for 24 weeks. Percent days of BTB and number of cycles with bleeding intervals > or =8 and > or =14 days were evaluated using daily bleeding diaries. Ovulation was determined by measuring thrice-weekly urinary metabolites of estrogen and progesterone. Endometrial concentrations of ER and PR were determined by immunohistochemistry. Mifepristone significantly decreased the percent days of BTB and the number of cycles with prolonged bleeding intervals when compared to placebo. No subject ovulated in either group. ER immunostaining increased and PR immunostaining decreased after mifepristone treatment. In conclusion, a 50 mg dose of mifepristone taken every 2 weeks decreases the incidence of BTB in new starters of DMPA. This effect may be due to modulation of endometrial estrogen and progesterone receptors. Results from a dose-ranging study in a selected group of de novo patients with rotational cervical dystonia (CD) suggest that 500 units of Dysport (Clostridium botulinum toxin type A haemaglutinin complex) is the optimal starting dose. The present study aimed to confirm the efficacy and safety profile of this dose in a population of CD patients more representative of those seen in a typical dystonia clinic. A total of 68 patients with moderate to severe CD (Tsui score > or = 9) were randomly assigned to receive placebo or Dysport 500 units. Treatment was administered according to the clinical pattern of head deviation, using a standardised injection protocol. A total of 21 patients (11 Dysport, 10 placebo) had not previously received botulinum toxin type A (BtxA) injections, and 47 patients (24 Dysport, 23 placebo) had received BtxA more than 12 weeks previously. Assessments were performed at baseline and weeks 4, 8 and 16. Patients defined as non-responders at week 4 were re-treated in an open phase with 500 units of Dysport at week 6, and were followed up at week 10. Significant between-group differences in Tsui scores were present at weeks 4 (p=0.001) and 8 (p=0.002). Similarly, there were significant between-group differences (p < 0.001) in patient and investigator assessments of response in favour of Dysport at weeks 4 and 8. Also, more Dysport (49%) than placebo (33%) patients were pain-free at week 4 (p=0.02). Overall, 30/35 (86 %) Dysport patients and 14/33 (42%) placebo patients were classified as responders at week 4. Adverse events were reported by 15/35 Dysport patients and 9/33 placebo patients. Open phase treatment produced improvements in Tsui (p < 0.001) and pain scores (p=0.011), and 23/24 patients were classified as responders. Although individual dose titration and muscle selection is desirable, this study demonstrated that a dose of 500 units of Dysport injected into clinically identified neck muscles without electromyographic guidance is safe and effective in the treatment of patients with the major clinical types of cervical dystonia.
A single injection of BtB was effective and safe for treating cervical dystonia. Long-term uncontrolled studies suggested that further injection cycles continue to work for most patients. 
Future research should explore technical factors such as the optimum treatment intervals and use of image or electromyographic guidance for administration. Other issues include service delivery, quality of life, long-term efficacy and safety, and the relative indications for BtA, BtB and other treatments such as deep brain stimulation