Validation of the Six Minute Walk Test (6MWT) in Ambulatory Amyotrophic Lateral Sclerosis (ALS) Patients (P01.107)

Objective: To validate 6MWT with outcome measures frequently used to evaluate motor performance in ALS which include the ALS Functional Rating Scale-Revised(ALSFRS-R), Quantitative Muscle Test(QMT), forced vital capacity(FVC), 4-step stair climbing(SC), 25-foot walk test(25FWT), and timed-up-and-go(TUG), and number of falls(F). Background Evaluation of motor impairments in ALS patient is necessary for clinical decision making, natural history, and efficacy of therapeutics. The recent surge in therapeutics with potential to improve rather than reduce progression of motor function in ALS may require a sensitive and meaningful functional outcome measure. 6MWT is being increasingly used in a variety of neurodegenerative motor system diseases including spinal muscular atrophy(Neurology 2010;74(10):833-838) and ALS(Arch Phys Med Rehabil 2010;91(12):1920-1929). Design/Methods: Distance during the 6MWT, ALSFRS-R, FVC, 25FWT, TUG, F, and QMT of bilateral hip, knee flexors and extensors, and ankle dorsiflexors were evaluated in 56 ambulatory ALS patients following standard procedures. TUG was evaluated as the time it took the patient to stand up from standard chair, walk 3 meters, and return to the chair. SC and 25FWT were evaluated as the time it took the patients to go up and down 4 steps and walk 25 foot respectively. Pearson9s correlations were used to test for linear relationships between the outcome measures. Results: 6MWT distance significantly correlated with ALSFRS-R total score(r=.49;p≤0.002), QMT(r=.58;p≤0.02), SC(r=-.57; p≤ 0.001), 25FWT(r =-.51;p≤ 0.005), and TUG(r =-.65;p≤ 0.001), but did not correlate with FVC(r=.18 p≤ 0.16). In addition, 6MWT significantlly correlated with number of falls, F(r=.42;p≤ 0.002)experienced by ALS patients. Conclusions: 6MWT correlates with other outcome measures that quantify lower extremity motor deficit in ALS, but does not correlate with FVC. 6MWT is a robust outcome measure expanding the dynamic range of treatment measurement in ambulatory ALS patients early in the disease. 6MWT correlates with the number of falls which is a meaningful safety-related outcome measure for ALS patients. Supported by: Carolinas ALS Research Fund, Pinstripes Fund, Carolinas Healthcare Foundation, Muscular Dystrophy Association/ALS Division. Disclosure: Dr. Sanjak has nothing to disclose. Dr. Langford has nothing to disclose. Dr. Holsten has nothing to disclose. Dr. Bockenek has nothing to disclose. Dr. Bravver has nothing to disclose. Dr. Desai has nothing to disclose. Dr. Bockenek has nothing to disclose. Dr. Williams has nothing to disclose. Ms. Russo has received personal compensation for activities with Serono, TEVA and Biogen as a consultant. Dr. Brooks has received personal compensation for activities with Avanir Pharmaceuticals, Bayer Healthcare Pharmaceuticals, Biogen Idec, Genentech, Inc., and Teva Neuroscience. Dr. Brooks has received research support from Avanir Pharmaceuticals, Biogen Idec, NINDS, Novartis, and Teva Neuroscience.