Background: Muscle cramps and pain associated with them can be seen in patients with amyotrophic lateral sclerosis (ALS) and are known to reduce the quality of life. Pharmacological treatment may not benefit all patients in treating these cramps. We assess the efficacy of Onabotulinum toxin A (BTX-A) in the treatment of lower limb cramps in patients with ALS. Methods: This retrospective chart review included a total of ten patients with ALS who suffered from pain due to lower limb cramps and were managed with BTX-A. Data including patient demographics, visual analog pain scale at different intervals during follow up, ALS functional rating scale and site of onset of ALS symptoms were documented. The pain score at baseline (before administration), at 3 months follow up and at 6 months follow up were compared using Wilcoxon test to assess BTX-A’s efficacy. Results: A significant improvement in average pain score due to cramps from baseline to the 6-month interval with a change of 3.1±0.7 (p<0.05,95%CI) was seen on the pain scale. No adverse events were noted during administration or post injections. Conclusion: Local BTX-A administration is an efficacious and safe procedure for improving pain associated with cramps in patients with ALS.

Abstract Introduction: Muscle cramps are a common occurrence in patients with peripheral neuropathy and are known to cause significant distress and decrease the quality of life. Although several drug formulations have been used in the management of cramps, there is significant variability in terms of efficacy and tolerability in patients with peripheral neuropathy. This study aims to assess the efficacy of botulinum toxin A in the management of lower limb cramps in patients with peripheral neuropathy.   Methods: This retrospective chart review included a total of ten patients with peripheral neuropathy with cramps. Relevant data such as age, gender, race, pain score and cause of peripheral neuropathy were documented. Statistical analyses to compare the variables was done using the Wilcoxon Test. The pain score before the administration, at 3-month, 6 month and 9 months follow up were compared.   Results All patients enrolled in the study showed improvement of pain assessed by visual pain analog scale. An improvement of 1.60 (95%CI, p<0.05), 2.70 (95%CI, p<0.05) and 3.50 (95%CI, p=0.05) was noted between test scores from before administration of botulinum toxin to 3-month, 6 months and 9 months follow up with a range of 6, 4 and 4 respectively.   Conclusion: Local BTX-A infiltration is a likely efficacious and safe procedure for improving pain associated with cramps in patients with peripheral neuropathy.