Use of rimabotulinum toxin for focal hypertonicity management in children with cerebral palsy with nonresponse to onabotulinum toxin.

Objective: The aim of this study was to review the effect of rimabotulinum toxin (BoNT-B) for focal hypertonicity management in children with cerebral palsy and secondary nonresponse to onabotulinum toxin treated at the authors' tertiary care academic medical center.

Design: A retrospective review of the medical treatment of children was conducted at the authors' institution (March 16, 2001, to August 2, 2002) using the key words botulinum toxin B and Myobloc (Solstice Neurosciences Inc, South San Francisco, CA). Demographic information was analyzed using descriptive statistics (number [percentage] and mean [range]). The Pearson χ test was used to evaluate differences in incidence of adverse events.

Results: Eighty-two children had BoNT-B injections (116 treatments). Overall, 26.8% (19/71) of the children or their parents/guardians reported no or minimal response to the injections, with 89.5% (17/19) of these children having secondary nonresponse to onabotulinum toxin. Adverse events were frequent but did not require hospitalization of any patient. No significant differences were found in incidence of adverse events related to BoNT-B dosing, medical fragility, or Gross Motor Function Classification System level.

Conclusions: More than one-fourth of the children receiving BoNT-B injections had nonresponse, with most having previous nonresponse to onabotulinum toxin. Adverse events related to BoNT-B injections were frequent and unpredictable but not severe.