The beneficial antispasticity effect of botulinum toxin type A is maintained after repeated treatment cycles
- 1Professor of Neurological Rehabilitation, Peninsula Medical School & Plymouth Primary Care Trust, Mount Gould Hospital, Plymouth PL4 7QD, UK
- 2Professor, Russian Medical Academy for Advanced Medical Studies, 5 Vtoroj Botinsky Projezd, Moscow 125101, Russia
- 3Professor, Pavlov’s State Medical University, 6/8 L. Tolstoy street, St Petersburg 197022, Russia
- 4Lead Researcher, Scientific Research Institute of Neurology, Russian Academy of Medical Sciences, 80 Volokolamskoye Shosse, Moscow 123367, Russia
- 5Senior Lecturer in Rehabilitation Medicine, University of Leeds & St James’s Hospital, Beckett St, Leeds LS9 7TF, UK
- 6Clinical Project Manager, Ipsen Ltd, 190 Bath Rd, Slough SL1 3XE, UK
- Correspondence to: Professor A M O Bakheit Mount Gould Hospital, Plymouth PL4 7QD, UK; magid.bakheitpcs-tr.swest.nhs.uk
- Received 29 December 2003
- Accepted 15 February 2004
- Revised 14 February 2004
Abstract
Objective: To study the efficacy, safety, and incidence of BtxA antibody formation with repeated treatments with BtxA in post-stroke upper limb muscle spasticity.
Methods: The study was a prospective open label trial. Patients with established post-stroke upper limb spasticity received 1000 units of BtxA (Dysport) into five muscles of the affected arm on study entry. Treatment was repeated every 12, 16, or 20 weeks as clinically indicated. Each patient received a total of three treatment cycles. Efficacy of treatment was assessed using the Modified Ashworth Scale. Patients were assessed on study entry and on week 4 and 12 of each treatment cycle for all safety and efficacy parameters. Blood samples for BtxA antibody assay were taken at baseline and on completion of the trial.
Results: Fifty one patients were recruited and 41 of them completed the study. Improvement from the cycle one baseline was observed in all the outcome measures. Mild to moderately severe treatment related adverse events were reported in 24% of cases. There were no serious adverse events. No BtxA antibodies were detected.
Conclusion: BtxA at a dose of 1000 units Dysport was efficacious in the symptomatic treatment of post-stroke upper limb spasticity. The study suggests that this effect can be maintained with repeated injections for up to at least three treatment cycles, with duration of effect per cycle of between 12 and 20 weeks. BtxA was safe in the dose used in this study and did not induce the formation of detectable levels of neutralising BtxA antibodies.
- BtxA, botulinum toxin type A
- MAS, Modified Ashworth Scale
- PD & CBRS, Patients’ Disability and Carer Burden Rating scale
- RCT, randomised controlled trials
- ROM, range of motion
Footnotes
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Competing interests: two of the authors (AMOB & BBB) have received in the past sponsorship for educational activities, including attendance at international scientific meetings, from Ipsen Ltd. LC is currently an employee of Ipsen Ltd.
