The main purpose of this study is to evaluate the efficacy and safety of injecting botulinum toxin A (BoNT-A) into the neck muscles to treat cervical dystonia (CD) in patients with dyskinetic cerebral palsy (CP).

This is a randomized, double-blinded, placebo-controlled trial with cross-over design. We prospectively enrolled adults with dyskinetic CP who were over 20 years old and had been clinically diagnosed with CD for more than one year. Patients were assessed using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) and the Numerical Rating Scale (NRS).

Seventeen patients were initially enrolled, but one patient was excluded after the final evaluation because of a violation of the study protocol. At 4 weeks, the BoNT-A injections showed significant improvement in TWSTRS total scores compared to the saline injections (P=0.0286 for ANCOVA). At 12 weeks, the BoNT-A injections resulted in greater improvements in TWSTRS total scores than the saline injections but this difference was not statistically significant (P=0.0783 for ANCOVA). Dysphagia occurred in 3 out of 16 patients; 2 after BoNT-A and 1 after saline. The dysphagia was transient and improved naturally within 2 weeks without any special treatment.

Botulinum toxin injection for cervical dystonia in adults with dyskinetic cerebral palsy is relatively safe and improves pain and disability.