The effect of botulinum toxin A injections in the spine muscles for cerebral palsy scoliosis, examined in a prospective, randomized triple-blinded study

STUDY DESIGN: A prospective, randomized triple-blinded cross-over design treating with either botulinum toxin A (BXT) or Saline (NaCl).

OBJECTIVE: To examine the efficacy of BTX treatment in cerebral palsy scoliosis (CPS).

SUMMARY OF BACKGROUND DATA: Intramuscular injections with BTX have been used off label in treating CPS. One prospective study has been conducted, demonstrating in both radiological and clinical improvement, whilst showing no side effects or complications.

METHODS: Subjects (brace treated CPS between 2 and 18 years) were injected using ultrasonic-guidance with either Saline or BTX in selected spine muscles with 6 months intervals (block randomization, sealed envelope). X-rays of the spine and clinical follow-up were captured before and 6 weeks after each injection. Primary outcome parameter was radiological change in Cobb's angle, where a seven degree change was regarded as an effect (1 SD). Radiological parameters were measured before and 6 weeks after treatment by 3 experienced doctors separately. Moreover, clinical results were evaluated by the pediatric quality of life (PQL) score and systematic open questioning of the parents about the child's wellbeing. Subjects, researchers and monitors were blinded during the trial. Appropriate permissions (2008-004584-19) and no funding were obtained.

RESULTS: Sixteen cerebral palsy patients (GFMCS III-V) with CPS were consecutively included, whereas 6 patients were excluded. There were no drop-outs to follow-up, but one possible serious adverse event of pneumonia resulting in death was recorded and the study was terminated. No significant radiological or clinical changes were detected when compared to NaCl injections using Wilcoxon matched pair signed-rank test.

CONCLUSION: No positive radiological or clinical effects were demonstrated by this treatment, except for the parent's initial subjective but positive appraisal of the effect. However, the study was terminated due to one possible severe adverse event and scheduled numbers needed to treat (hence power) were not reached.