Accuracy of intramuscular injection of botulinum toxin A in juvenile cerebral palsy: a comparison between manual needle placement and placement guided by electrical stimulation.

Most clinicians who perform botulinum toxin A injections for children with cerebral palsy do so using the "free-hand" or manual technique without using radiologic or electrophysiologic guidance to aid needle placement. The objective of this study was to investigate the accuracy of manual needle placement compared with needle placement guided by electrical stimulation. A total of 1,372 separate injections for upper and lower limb spasticity were evaluated in 226 children with cerebral palsy. The accuracy of manual needle placement compared with electrical stimulation was acceptable only for gastroc-soleus (>75%); it was unacceptable for the hip adductors (67%), medial hamstrings (46%), tibialis posterior (11%), biceps brachii (62%), and forearm and hand muscles (13% to 35%). The authors recommend using electrical stimulation or other guidance techniques to aid accurate needle placement in all muscles except the gastroc-soleus. Further study is needed to determine whether more accurate injecting will lead to better functional outcomes and more efficient use of botulinum toxin A.