[Botulin toxin for spasticity in spinal cord damage by treating the motor endplate]

Therapeutic injection of botulin toxin is well-recognized for reducing tonus in local dystonia. However, its efficacy in reducing spasticity in spinal cord injuries is still unproven. 4 men and 1 woman (mean age 39 years, range 20-56) with spinal cord injury and debilitating spasticity, and no response to standard treatment for spasticity received injections of botulin, 200-300 U, into 4-8 points in their legs to block muscle-nerve synapses. In all 5 tonus was reduced in the area of the block, while in some it was also reduced in more distal muscles. In 1 there was reduced tonus in both the injected and contralateral leg. The therapeutic effect on tonus persisted for 3 months. In spite of objective improvement in tonus in all 5, only 3 felt subjective improvement, but in none was there improvement on standard functional scaling. We found injection of botulin toxin effective in reducing tonus in the spinal cord-injured, and to some extent in improving subjective feeling of well-being in some of them. Objective measurement might show functional improvement after larger doses of toxin injected into more muscles. This might be necessary because the muscle mass of the legs is large and the intensity of involuntary contraction is especially high in these patients.