Objective
To evaluate the effects of the dilution volume of botulinum toxin A on spasticity of children with cerebral palsy. Method: Total 18 legs of 9 children with cerebral palsy were enrolled. 100 units of botulinum toxin were diluted with 4 cc or 2 cc of normal saline and injected to the medial and lateral heads of Gastrocnemius. Modified Ashworth scale, modified Tardieu test and range of motion (ROM) of ankle and knee were measured. Measurements were obtained before and at 1, 7, 14, 30, 60, 90, and 180 days after injection, respectively. Results: Spasticity tested by modified Ashworth scale and modified Tardieu test decreased and ROM of ankle and knee increased after 14 days since injection in both groups (p＜0.05). In low dilution group, maximal ROM of ankle and knee was obtained at 30^th day after injection. In high dilution group, maximal ROM of ankle and knee was achieved at 14^th day after injection and maximal ROM of knee at 30^th day after injection. However, there was no significant differences between high dilution group and low dilution group in different times. Conclusion: Management of spasticity with botulinum toxin in cerebral palsy was not related to dilution volume. (J Korean Acad Rehab Med 2008; 32: 294-299)