A Novel Muscle Cramp Scale for Patients with ALS

Objective: To develop a new muscle cramp scale. Background: Clinical trials in the past have utilized a cramp diary that details the number, location, and severity of muscle cramps. Design/Methods: We have developed an outcome measure to assess muscle cramps in ALS, which contains four 5-point subdomains consisting of 1) cramp-triggering factors, 2) frequency, 3) location, 4) severity, and a 5) 10-point visual scale assessing the degree in which the cramp affects overall daily living. Results: Thirty patients with ALS, who experienced a daily cramp or at least 3 cramps per week, participated in a test-retest study. An additional 26 patients participated in a second study assessing changes over 4 weeks using the cramp scale in conjunction with a cramp diary. To assess the internal reliability of the scale, a Cronbach’s coefficient value of α=0.75 was considered acceptable. Test and retest by in-person and telephone administration did not differ, and Cohen’s kappa statistics revealed moderate to high agreement for each item (range 0.60 to 0.95, P Conclusions: This study showed that the ALS muscle cramp scale is a valid, simple, and quick measure that can be administered either in person or by telephone. It can be used for assessment of muscle cramps in patients with ALS. Disclosure: Dr. Mitsumoto has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Mitsubishi-Tanabe Pharma. Dr. Mitsumoto has received research support from Tsumura \u0026 Co, Cytokinetics. Dr. Gilmore has nothing to disclose. Dr. Chiuzan has received research support from Tsumura \u0026 Co. Dr. Ibagon has nothing to disclose. Dr. Zhang has nothing to disclose. Dr. McHale has nothing to disclose. Dr. Likanje has nothing to disclose. Dr. Hupf has nothing to disclose.