Botulinum toxin treatment of hip adductor spasticity in multiple sclerosis

Spasticity results in a resistance to passive movement and decrease of pass ive mobility of the involved joints and is defined as a state of hypertonic ity with exaggeration of tendon reflexes mediated by a loss of inhibitory c ontrol of upper motor neurons. In patients with severe stages of multiple s clerosis (MS) spasticity of the lower limbs often leeds to a spastic patter n with hip adduction resulting in decreased range-of-motion (ROM), increase d pain, spasms, and functional disability (disturbed gait and sitting posit ion) as well as difficulties with perineal hygiene. Local botulinum toxin type A (Btx-A) injections in spastic muscles offer a new treatment approach for managing spasticity and associated problems. Up to now Btx-A is approved for the treatment of blepharospasm and cervical dy stonia and the treatment of equinous gait in children with cerebral palsy i n Austria and Germany. Up to now only in Switzerland Botox((R)) is licensed for the treatment of focal spasticity. Btx-A is a neurotoxin derived from Clostridium botulinum. In most european countries Btx-A is available as Dysport((R))) (vial = 500 units) and Botox( (R)) (vial = 100 units). In prospective studies a ratio of 1 unit Botox (R) to 3-4 units Dysport((R)) was found. Following intramuscular injection Btx -A blocks the release of acetylcholine at the neuromuscular junctions, ther eby inhibiting muscle contraction, and decreases spastic muscle tone and mu scle spindles afferent information to the spinal cord. The spectrum of side effects includes local weakening of the injected and adjacent muscles as w ell as pain and haematoma at the injection site. At therapeutic doses side effects are local and transient. According to a double blind, placebo controlled, dose ranging study publish ed by Hyman et al. (2000, Dysport((R)) in a dose of 500, 1000 and 1500 unit s reduced the degree of hip adductor spasticity associated with MS, and thi s benefit was evident despite concomitant use of oral antispasticity medica tion. According to the results of the study there was a clear trend towards greater efficacy and duration of effects with higher doses of Dysport((R)) . Taking efficacy and adverse events into account (incidence of muscle weak ness was higher for the 1500 units group than for placebo) the optimal dose for hip adductor spasticity seems to be 1000 units Dysport((R)) divided be tween the adductor magnus, longus and brevis muscles and between both legs. To increase Btx-A effects following injection of hip adductors additional p hysiotherapy and casting or orthosis to increase passive hip-abduction is r ecommended. According to the literature anatomical localisation of the addu ctor muscles for injection and aspiration following insertion of the needle , to avoid injection of the toxin into a vessel, should be performed. A max imum dose of 1500 units Dysport((R)) (400 units Botox((R))) per treatment s ession and 250 units Dysport((R)) (50 units Botox((R))) per injection site is recommended. See table for dose-range of Dysport, and Botox((R)) in the treatment of adult patients with hip-adductor spasticity. For evaluation of treatment effects in hip adductor spasticity clinical exa mination with specific scales and measurements (see Appendix) at baseline, 4 and 12 weeks following BtxA injection is recommended: - Global rating of severity (0-4; patient's self assessment and physician's rating) - Global rating of response (- 4 - + 4; patient's self assessment and physi cian's rating) - Visual Analogue Scale (patient's self assessment of pain) - Active and passive ROM (manual goniometer) - Distance between the medial femur condyles in thigh extension (distance i n cm) - Modified Ashworth scale (0-4) - Ten meter walking time (seconds) - Functional Ambulation Categories (0-5) - Score of perineal hygiene (0-5).