COMPARISON OF PHENOL BLOCK AND BOTULINUS TOXIN TYPE A IN THE TREATMENT OF SPASTIC FOOT AFTER STROKE

Abstract

Locally acting treatments for spasticity such as nerve and motor point blocks have the advantage of reducing harmful spasticity in one area, while preserving useful spasticity in another area. This randomized, double-blind study is the first trial that was designed to find out whether botulinus toxin Type A and phenol relieves the signs and symptoms of ankle plantar flexor and foot invertor spasticity after stroke and if either of these methods offers any advantages and disadvantages over the other. Twenty patients who were included in this preliminary study were randomly assigned to receive a single treatment of 400 mouse units of botulinus toxin Type A injected into the calf muscles or to receive a tibial nerve blockade with 3 ml of 5% phenol. A combination of subjective and objective measures were used to assess functional change at baseline and at Weeks 2, 4, 8, and 12. At follow-up, significant improvement (P < 0.05) in the Ashworth score for dorsiflexion was observed in both groups. The change in the Ashworth score for eversion was significant in the group that received botulinus toxin Type A (P < 0.05) but not in the group that received phenol (P > 0.05). When those variables were compared between the two groups, the change in the Ashworth score at Weeks 2 and 4 was significantly better in the group that received botulinus toxin Type A (P < 0.05) but there was not a significant difference between the two groups at Weeks 8 and 12 (P > 0.05). The decrease in clonus duration that was detected by electromyography was significant in both groups at all visits, but the decrease in the group that received botulinus toxin Type A was significantly better at Weeks 2 and 4 (P < 0.05). It is concluded that both motor point injections with botulinus toxin Type A and tibial nerve blockade with phenol are effective in plantar flexor spasticity, but the changes were more significant in the group that received botulinus toxin Type A at Weeks 2 and 4, whereas there was not a significant difference between the two groups at Weeks 8 and 12. Future research should explore the long-term effect of these two treatment modalities.