Botulinum toxin A (Dysport®): in dystonias and focal spasticity

Dysport®, a formulation of botulinum toxin A, blocks acetylcholine release at neuromuscular junctions causing denervation and temporary muscle paralysis. It is used to treat several medical conditions, including dystonias and focal spasticity. Subcutaneous Dysport® was effective in improving functional disability in adults with blepharospasm in a placebo-controlled trial with 16 weeks' follow-up, and in adults with hemifacial spasm in case series. Similarly, intramuscular Dysport® was effective in improving symptoms of cervical dystonia in adults, focal spasticity in adults with post-stroke upper limb spasticity and dynamic equinus spasticity in paediatric patients with cerebral palsy in placebo-controlled trials with up to 20 weeks' follow-up. However, in two 12-week, placebo-controlled trials in adults with focal lower limb spasticity (spastic equinovarus deformity after stroke and hip adductor spasticity associated with multiple sclerosis) intramuscular Dysport® had limited efficacy. Available longer-term data indicated that Dysport® treatment was effective over several treatment cycles in patients with cervical dystonia or upper limb spasticity. Dysport® was generally well tolerated in patients with dystonias or focal spasticity. Most adverse events were mild to moderate and transient.