Abstract: ObjectiveTo investigate the optimal dose of botulinum toxic A (BTX-A) block to relax spasticity in cerebral palsy.Methods61 children (27～144 months old) with spastic cerebral palsy were treated by BTX-A block and divided into A, B, C, D and E groups according to the dose coefficient. The dose of BTX-A block was 30～160 IU (average 69.0±32.4 IU) according to the weight and the score of Modified Ashworth Scale.Results55 BTX-A blocks were successful. The muscles tone turned below and the function were improved. The effective rate was 90.16%. The effective time ranged from 8 weeks to 32 weeks, average 17.56±8.30 weeks. The effective time of the group C (2≤dose-coefficient<3) was the longest in the five groups.ConclusionThe optimal dose of BTX-A block in triceps surae should be counted as follow: dose(IU)=(score of Modified Ashworth Scale+2.5)×weight(kg).

Key words: cerebral palsy, spasticity, botulinum toxic A (BTX-A), dose, nerve block