Botulinum toxin type A and ethyl alcohol for treating lower extremity spasticity after stroke

Abstract

Objective To compare the effectiveness of botulinum toxin type A (BTXA) and ethyl alcohol (EA) in treating lower extremity spasticity after stroke. Methods This was a randomized, case-control study. A total of 92 eligible stroke survivors completed the study. They were randomly divided into a BTXA group of 48 and an EA group of 44 according to a random number table. The gastrocnemius, soleus and posterior tibial muscles of the affected limb were chosen as injection sites. The BTXA group was injected with 50 to 200 IU of BTXA (at 50 U/ml) at one to four sites in each muscle, with a total injection dose of less than 600 U. The EA group was injected with less than 10 ml of 50% EA (0.1 to 0.5 ml at each site). Before and 2, 4 and 12 weeks after the injection, both groups were evaluated using the modified Ashworth scale (MAS), a 3 m timed up and go test (TUG), a timed 10 meter walk (10m-WT) and each was asked to assess their pain level using a visual analogue scale (VAS). Any adverse reactions were also observed. Results Two weeks after the injection, the average MAS score of both groups had improved significantly compared to that before the injection. The average improvement in the BTXA group was significantly less than in the EA group. No significant differences were found in other measurements. After four weeks the average MAS score of the BTXA group was still significantly different from that before injection or from 2 weeks previously, but the EA group now showed no significant difference from before the injection. The average TUG, 10m-WT and VAS scores of both groups had improved significantly compared to those of the earlier time points. Twelve weeks after the injection, the average MAS, TUG, 10m-WT and VAS scores of the BTXA were still significantly improved compared to before the injection, but in the EA group only the average score VAS reading was significantly improved. There were then significant differences between the two groups in all of the measurements. Conclusions Both BTXA and EA can relieve muscle spasticity. Both take effect within 2 weeks, but the former has fewer side effects than the latter and a longer duration of therapeutic effect. Key words: Botulinum toxin, type A; Ethyl alcohol; Stroke; Lower limb spasticity; Neuromuscular blockade