Botulinum toxin as treatment for focal dystonia: a systematic review of the pharmaco-therapeutic and pharmaco-economic value

Abstract

Focal dystonia is a common, invalidating neurologic condition characterized by involuntary, sustained muscle contractions causing twisting movements and abnormal postures in one body part. Currently, botulinum toxin is the treatment of first choice. We performed a systematic review towards the pharmaco-therapeutic and pharmaco-economic value of botulinum toxin as treatment for focal dystonia, which yielded the following results. Botulinum toxin is the most effective treatment for reducing dystonic symptoms measured with dystonia-specific and general questionnaires, and pain in patients with focal dystonia. Seventy-one percent of patients with cervical dystonia had a reduction in neck pain compared to 12 % in placebo groups. Adverse events occur in 58 % of patients during treatment with botulinum toxin compared to 46 % treated with placebo. Especially dry mouth, neck weakness, dysphagia, and voice changes are common. Adverse events are usually mild and self-limiting. Health-related quality of life, measured with the SF-36 is 20–50 points lower in patients with focal dystonia compared to controls and the effect of botulinum toxin on health-related quality of life is unclear. Botulinum toxin treatment is expensive because the drug itself is expensive. Yearly costs for treating a patient with focal dystonia with botulinum toxin range from EUR 347 to EUR 3,633 and the gain in QALYs with BTX treatment is small. Focal dystonia impairs the productivity and the ability to work. At start of botulinum toxin treatment only 47–50 % was working. Botulinum toxin partly improves this. Overall, we conclude that botulinum toxin is an expensive drug with good effects. From a societal perspective, the costs may well weigh up to the regained quality of life. However, the available literature concerning costs, health-related quality of life and labor participation is very limited. An extensive cost-effectiveness study should be performed incorporating all these aspects.Electronic supplementary materialThe online version of this article (doi:10.1007/s00415-012-6510-x) contains supplementary material, which is available to authorized users.

Botulinum toxin type A versus botulinum toxin type B for cervical dystonia

“…At the average age of 40 years, almost half of the patients quit working or retire early due to dystonia, and 10 years later, only 25% of patients are working compared to 62% of the general population (Zoons 2012). Moreover, health-related quality of life is significantly diminished, mainly attributable to depression and anxiety, with scores comparable to patients with multiple sclerosis, Parkinson's disease or stroke (Zoons 2012).…”

How Effective and Safe is Botulinum Toxin Therapy in Cervical Dystonia: The Current Stand

“…Reviews of "oNT treatment for CD suggest that 70-90% of patients derive symptomatic beneit from "oNT with at least one injection [29][30][31]. In a meta-analysis (8 trials with 361 patients using Ona"oNT"; 5 trials with 319 patients using "bo"oNT"), it was shown that there was a statistically and clinically signiicant improvement on objective rating scales and subjective rating scales as well as for pain relief in subjective scales [7].…”

Recent developments in dystonia

“…The botulinum toxins continue to serve as the main therapy for most patients with focal and segmental dystonia (39–41), including both isolated or combined dystonia syndromes. Several safe and effective formulations are available in different parts of the world.…”