The Optimal Dose Choosing Study Of The Botulinum Toxin Type A In The Treatment For The Spasticity Of Children With Cerebral Palsy

ObjectiveTo investigate the relationship between the optimal dose of BTX—A and the spasticity of cerebral palsy and so on,and to search the method of calculate the optimal dose of BTX—A.Materials and MethodsThe study was divided into three parts.Part one: This part is the retrospective study. From June 2003 to December 2004, 39 children with CP was treated by BTX—A to release the spasticity in our hospital. Among these children , 23 children of CP (male 15, female 8, mean age 60.7±26.9 months, range 33 to 145 months) had good curative effect.Part two: From January 2005 to March 2006, 58 children with CP(male 38, female 20, mean age 59.3±24.6 months, range 27 to 144 months) was treated by BTX—A release the spasticity in our hospital. According to the coefficient, the children were randomly divided into five groups.Part three: From June 2006 to October 2006, 15 children with CP(male 9, female 6, mean age 60.1±21.5 months, range 36 to 102 months) was treated by BTX—A release the spasticity in our hospital. The dose of BTX—A was calculated by the formula. The 15 children was trial group, the 58 children in part two was control group.The drugs are BTX- A which were made by Lanzhou Institute of Biological Products. The articles for use include nerve block insulative needles which were made in Japan, injection syringe, electric paste, surface electrode, wire, stimulator and so on.According to the muscles and nerves anatomical position, the cathelectrode of the stimulator was pasted by adhesive plaster in the antagonist's skin. The stimulator was set as 5Hz and 3mA. Find the point with the anticathode repeatedly and adjust the intensity of current at the same time. The muscle can contract with the least intensity of current at the point. The point was called nerve block sign and was marked.Connect the insulative needles with the anticathode of the stimulator and puncture the skin through the nerve block sign. Adjust the needle and the intensity of current until the muscle can contract with the least intensity of current. Then inject the medicine.Results(1) There is no correlation between the optimal unit dose of BTX—A and the sex, age, body weight, diagnosis type, GMFCS level, etiological factor and the injections. There is linear positive correlation between the optimal unit dose of BTX—A and the Modified Ashworth Scale. The initial formula of the optimal dose: dose =(1+ coefficient×MAS)×body weight.(2) According to the improving of motor function, the BTX—A dose of group C is optimal. According to the effective endurance, the BTX—A dose of group D is optimal. The optimal coefficient is 1.8.(3) The improvement of motor function in trial group is more than in control group. The effective endurance in trial group is longer than in control group.Conclusions(1) There is linear positive correlation between the optimal unit dose of BTX—A and the Modified Ashworth Scale.(2) The formula of the optimal BTX—A dose in triceps muscle of calf: dose =(1+ 1.8×MAS)×body weight.(3) Using the formula, the BTX—A curative effect can be increased and the effective endurance can be lengthened.