Treatment of Spastic Equinus Gait with Botulinum Toxin A: Does Dose Matter? Analysis of a Clinical Cohort

Abstract

Introduction: This study reports the effects of various doses of BTX‐A when treating equinus gait in cerebral palsy in a clinical setting at a tertiary hospital. Patients: Twenty-nine children with CP (age 1.5 - 9.6 yrs, GMFCS I - IV) met the preset inclusion criteria. The treatment episodes per child ranged from 1 to 5 and the effects on a total of 80 legs in 55 treatment sessions were evaluated. Methods: BTX‐A doses injected into the gastroc-soleus muscle were divided into low- (≤ 6 units/kg bw) and high- (> 6 units/kg bw) dose groups. The outcome measurements included active and passive ankle range of movement, Modified Ashworth Scale, dynamic muscle length, Selective Motor Control score, Observational Gait Scale score, and Goal Attainment Scale score at pre-treatment and 1, 2, and 4 months post-treatment. Results: The only differences between the treatment groups were observed at 2 and 4 months in terms of change in passive ankle ROM and at 4 months in change in selective dorsiflexion, favouring the low-dose group. The incidence and severity of side-effects did not differ between the groups. Conclusion: Doses over 6 units/kg bw injected into the gastroc-soleus muscle do not necessarily yield superior results compared with lower doses.

Key words

Botulinum toxin type A - Equinus gait - Cerebral Palsy - Spasticity - Dosage

References

• 1 Baker R, Jasinski M, Maciag-Tymecka I, Michalowska-Mrozek J, Bonikowski M, MacLean J. et al . Botulinum toxin treatment of spasticity in diplegic cerebral palsy: a randomized, double-blind, placebo-controlled, dose-ranging study.  Dev Med Child Neurol. 2002;  44 666-675
• 2 Bakheit A MO, Severa S, Cosgrove A, Morton R, Roussonis S H, Doderlein L, Lin J-P. Safety profile and efficacy of botulinum toxin A (Dysport) in children with muscle spasticity.  Dev Med Child Neurol. 2001;  43 234-238
• 3 Bohannon R W, Smith M B. Interrater reliability of a modified Ashworth scale of muscle spasticity.  Phys Ther. 1987;  67 206-7
• 4 Boyd R, Graham H K. Botulinum toxin A in the management of children with cerebral palsy: indications and outcome.  Eur J Neurol. 1997;  4 15-22
• 5 Boyd R N, Graham H K. Objective measurement of clinical findings in the use of botulinum toxin type A for the management of children with cerebral palsy.  Eur J Neurol. 1999;  6 23-35
• 6 Cardoso E S, Rodrigues B M, Barroso M, Menezes C J, Lucena R S, Nora D B, Melo A. Botulinum toxin type A for the treatment of spastic equinus foot in cerebral palsy.  Pediatr Neurol. 2006;  34 106-109
• 7 Corry I S, Cosgrove A P, Duffy C M, McNeill S, Taylor T C, Graham H K. Botulinum toxin A compared with stretching casts in the treatment of spastic equinus: a randomised prospective trial.  J Pediatr Orthop. 1998;  18 304-311
• 8 De Paiva A, Meunier F A, Molgo J, Aoki K R, Dolly J O. Functional repair of motor endplates after botulinum neurotoxin type A poisoning: biphasic switch of synaptic activity between nerve sprouts and their parent terminals.  Proc Natl Acad Sci USA. 1999;  96 3200-3205
• 9 Eames N WA, Baker R, Hill N, Graham K, Taylor T, Cosgrove A. The effect of botulinum toxin A on gastrocnemius length: magnitude and duration of response.  Dev Med Child Neurol. 1999;  41 226-232
• 10 Flett P J, Stern L M, Waddy H, Connell T M, Seeger J D, Gibson S K. Botulinum toxin A versus fixed cast stretching for dynamic calf tightness in cerebral palsy.  J Paediatr Child Health. 1999;  35 71-77
• 11 Graham H K, Aoki K R, Autti-Rämö I, Boyd R N, Delgado M R, Gaebler-Spira D J, Gormley Jr M E, Guyer B M, Heinen F, Holton A F, Matthews D, Molenaers G, Motta F, Garzia Ruiz P J, Wissel J. Recommendations for the use of botulinum toxin type A in the management of cerebral palsy.  Gait Posture. 2000;  11 67-79
• 12 Jefferson R J. Botulinum toxin in the management of cerebral palsy.  Dev Med Child Neurol. 2004;  46 491-499
• 13 Koman L A, Mooney J F, Smith P B, Goodman A, Mulvaney T. Management of spasticity in cerebral palsy with botulinum-A toxin: report of a preliminary, randomized, double-blind trial.  J Pediatr Orthop. 1994;  14 299-303
• 14 Koman L A, Mooney J F, Smith P B, Walker F, Leon J M. Botox study group . Botulinum toxin type A neuromuscular blockade in the treatment of lower extremity spasticity in cerebral palsy: a randomized, double-blind, placebo-controlled trial.  J Pediatr Orthop. 2000;  20 108-115
• 15 Love S C, Valentine J P, Blair E M, Price C J, Cole J H, Chauvel P J. The effect of botulinum toxin type A on the functional ability of the child with spastic hemiplegia: a randomized controlled trial.  Eur J Neurol. 2001;  8 50-58
• 16 Maloney F P, Mirrett P, Brooks C, Johannes K. Use of the goal attainment scale in the treatment and ongoing evaluation of neurologically handicapped children.  Am J Occup Ther. 1978;  32 505-510
• 17 Palisano R, Rosenbaum P, Walter S, Russell D, Wood E, Galuppi B. Development and reliability of a system to classify gross motor function in children with cerebral palsy.  Dev Med Child Neurol. 1997;  39 214-223
• 18 Polak F, Morton R, Ward C, Wallace W A, Doderlein L, Siebel A. Double-blind comparison study of two doses of botulinum toxin A injected into calf muscles in children with hemiplegic cerebral palsy.  Dev Med Child Neurol. 2002;  44 551-555
• 19 Rodda J, Graham H K. Classification of gait patterns in spastic hemiplegia and spastic diplegia: a basis for a management algorithm.  Eur J Neurol. 2001;  8 98-108
• 20 Russman B S, Tilton A, Gormley M E. Cerebral palsy: A rational approach to a treatment protocol, and the role of botulinum toxin in treatment.  Muscle Nerve. 1997;  20 181-193
• 21 Sloop R R, Escutin R O, Matus J A, Cole B A, Peterson G W. Dose-response curve of human extensor digitorum brevis muscle function to intramuscularly injected botulinum toxin type A.  Neurology. 1996;  46 1382-1386
• 22 Stuber W A, Fuchs R H, Miedander J A. Reliability of goniometric measurements of children with cerebral palsy.  Dev Med Child Neurol. 1988;  30 657-666
• 23 Sutherland D H, Kaufman K R, Wyatt M P, Chambers H G, Mubarak S J. Double-blind study of botulinum A toxin injections into the gastrocnemius muscle in patients with cerebral palsy.  Gait Posture. 1999;  10 1-9
• 24 Ubhi T, Bhakta B B, Ives H L, Allgar V, Roussounis S H. Randomised double blind placebo controlled trial of the effect of botulinum toxin on walking in cerebral palsy.  Arch Dis Child. 2000;  83 481-487
• 25 Wissel J, Heinen F, Schenkel A, Doll B, Ebersbach G, Muller J, Poewe W. Botulinum toxin A in the management of spastic gait disorders in children and young adults with cerebral palsy: a randomized, double-blind study of “high-dose” versus “low-dose” treatment.  Neuropediatrics. 1999;  30 120-124