As investigators on a number of
previous randomized clinical trials evaluating the use of Botulinum
toxin in spasticity associated with cerebral palsy, we read with interest
the article by Kay et al, (1). Botulinum toxin A has been widely investigated in a range of animal
and clinical studies and certain broad generalizations can be made from
the literature:
1. Botulinum neurotoxin A has a high affinity for presynaptic
cholinergic nerve terminals and has a predictable dose dependent
consistent clinical effect when injected into skeletal muscles affected by
spasticity (2,3).
2. The harnessing of this predictable biochemical effect has been
established in a wide range of clinical studies such that the evidence for
the efficacy of the intervention is greater than for any other medical or
surgical procedure currently used in the management of cerebral palsy (4).
3. The principal indication for the clinical use of Botulinum
neurotoxin A in children with spasticity associated with cerebral palsy is
for the temporary, focal or regional reduction in spasticity to facilitate
more normal patterns of motion and on occasions to improve function. In
previous work we defined the indication for injection of Botulinum toxin
in cerebral palsy to be “dynamic spasticity interfering with function in
the absence of fixed contracture” (2,3).
The principal indication for use of Botulinum neurotoxin A in
cerebral palsy was and remains reduction of spasticity. However we
recognize that many “niche applications” have been explored by other
investigators including Kay et al (1,5).
Although we have used Botulinum toxin as an adjunct to serial casting
and our anecdotal evidence suggests that it is effective, it is very
important to stress that this is not the primary application of this
therapy. It was therefore somewhat of a surprise for us to see that Kay
et al made a direct comparison between their findings and our studies in
which we made a concerted effort to exclude children with fixed
contractures. The purpose of the study by Corry et al(6) and Flett et al (7)
were clearly to compare two methods of spasticity management for equinus
gait not contracture management. In addition, the recommendations for the
use of serial casting after Botulinum toxin are to change the casts at
weekly intervals and to restrict casting to a period of two weeks in most
children or a maximum of three weeks8.
Given that this is the first clinical trial to be published in the
Journal of Bone and Joint Surgery addressing the use of Botulinum toxin in
cerebral palsy, it is very important for the readers of the journal to
understand that the use of Botulinum toxin in the management of dynamic
spasticity is supported by a high level of evidence (3,4). The use of
Botulinum toxin in this niche application, as an adjunct to serial casting
for the management of fixed contractures, is not.
RICHARD BAKER
Gait Analysis Service Manager
The Hugh Williamson Gait Laboratory
The Royal Children’s Hospital
Flemington Road
Parkville
Victoria 3052
Australia
E-mail: richard.baker@rch.org.au
ROSLYN BOYD
Senior Physiotherapist
Department of Orthopaedics
The Royal Children’s Hospital
Flemington Road
Parkville
Victoria 3052
Australia
E-mail: roslyn.boyd@rch.org.au
PETER J FLETT
Director Paediatric Rehabilitation
Department of Child and Adolescent Development,
Neurology and Rehabilitation
Women’s and Children’s Hospital
Adelaide
South Australia
Australia
E-mail: flettp@wch.sa.gov.au
H. KERR GRAHAM
Professor of Orthopaedic Surgery
Orthopaedic Department
The Royal Children’s Hospital
Flemington Road
Parkville
Victoria 3052
Australia
E-mail: kerr.graham@rch.org.au
References
1. Kay RM, Rethlefsen SA, Fern-Buneo A, Wren TAL, Skaggs DL.
Botulinum toxin as an adjunct to serial casting treatment in children with
cerebral palsy. J Bone Joint Surg Am 2004; 86:2377-84
2. Cosgrove AP, Corry IS, Graham HK. Botulinum toxin in the
management of the lower limb in cerebral palsy. Dev Med Child Neurol
1994:36:386-96
3. Baker R, Jasinski M, Maciag-Tymecka I, Michalowska-Mrozek J,
Bonikowski M, Carr L, MacLean J, Lin J-P, Lynch B, Theologis T, Wendorff
J, Eunson P, Cosgrove A. Botulinum toxin treatment of spasticity in
diplegic cerebral palsy: a randomized, double-blind, placebo-controlled,
dose-ranging study. Dev Med Child Neurol 2002;44:666-75
4. Boyd RN, Hays RM. Current evidence for the use of botulinum toxin
type A in the management of children with cerebral palsy: a systematic
review. Eur J Neurol 2001;8: Supp 5: 1-20
5. Graham HK, Aoki KR, Autti-Ramo I, Boyd RN, Delgado MR, Gaebler-
Spira DJ, Gormley ME, Guiyer BM, Heinen F, Holton AF, Matthews D,
Molenaers G, Motta F, Garcia Ruiz PJ, Wissel J. Recommendations for the
use of botulinum toxin type A in the management of cerebral palsy. Gait
and Posture 2000;11:67-79
6. Corry IS, Cosgrove AP, Duffy CM, McNeill S, Taylor TC, Graham HK.
Botulinum toxin A compared with stretching casts in the treatment of
spastic equinus: a randomised prospective trial. J Pediatr Orthop
1998;18:304-11
7. Flett PJ, Stern LM, Waddy H, Connell TM, Seeger JD, Gibson SK.
Botulinum toxin A versus fixed cast stretching for dynamic tightness in
cerebral palsy. J Paediatr Child Health 1999;35:71-7
8. Boyd RN, Graham HK. Botulinum toxin A in the management of
children with cerebral palsy indications and outcome. Euro J Neurol
1997; 4 (supple 2):15-22
Letters to the Editor: ![[Read Letter to the Editor]](/icons/misc/sectionDOWN.gif){kind=icon}
