Walking Capacity [WalkCap] Measured by Six-Minute Walk (6MW) Does Not Demonstrate Fatigue in Patients with Amyotrophic Lateral Sclerosis (ALS), Multiple Sclerosis (MS),and Parkinson Disease (PD) (P3.071)

OBJECTIVE: To assess fatigability of WalkCap measured by 6MW across ambulatory ALS, MS, and PD patients. BACKGROUND: Evaluation of functional walking capacity (WalkCap) in ambulatory patients with neurodegenerative diseases [ALS/MS/PD] is important for clinical decision making, natural history, efficacy of therapeutics and needs assessment. The 6MW is an objective, standardized and reliable test of WalkCap. Weakness, fatigue, and hypokinesia limit mobility and may interfere with WalkCap as measured throughout the walking distance [WalkDist] during the 6MW. DESIGN/METHODS: WalkCap of 45 ALS, MS, and PD patients (15 patients in each group) was evaluated using by WalkDist achieved at 2, 4, and 6 minutes during 6MW. Other clinical measures included timed-up-and-go (TUG), 25-foot walk (25FW), handheld dynamometry, and the gross motor score ALS Functional Rating Scale-Revised (ALSFRS-R), Unified Parkinson9s Disease Rating Scale (UPDRS), Multiple Sclerosis Impact Scale (MSIS-29). RESULTS: WalkDist in meters and in (% predicted re normal) was statistically significantly [P=0.001] less in ALS than MS, and PD respectively [297.0±103 (56.8%±26) in ALS /470.3±110 (82.0%±19) in MS/474.2±71 (92%±11) in PD]. No change in WalkDist was recorded at 0-2/2-4/4-6 minutes in ALS [103±32/100±32/93±40, MS [153±4/157±39/159±44] or PD [149±21/162±26/162±25]. The 6MW % predicted distance correlated with grip strength bilaterally (r=0.532; p=0.002), TUG (r=-0.829; p=0.001), (25FWT r=-0.832; p=0.001, gross motor ALSFRS-R score (r=0.639, p=0.02), MSIS score (item 1-20) (r=-0.541; p=0.004), but not with UPDRS-motor score (r=0.227, p=0.598). CONCLUSIONS: WalkCap of ambulatory ALS, MS, and PD during 6MW is not affected by motor fatigue. WalkCap was higher in ambulatory patients with stronger grip, faster in TUG and 25FW. WalkCap measured by 6MW can be used as a simple outcome measure to evaluate lower extremity impairments in various neurological diseases. Discordance between WalkCap and the UPDRS-motor scale in mildly affected PD patients indicates that 6MW may provide additional information regarding these patients in clinical practice and clinical research trials. Study Supported by: Carolinas ALS Research Fund, Pinstripes Fund, Carolinas Healthcare Foundation, Muscular Dystrophy Association/ALS Division Disclosure: Dr. Sanjak has nothing to disclose. Dr. Morgan has nothing to disclose. Dr. Simpson has nothing to disclose. Dr. Holsten has nothing to disclose. Dr. Hirsch has nothing to disclose. Dr. Englert has received personal compensation in an editorial capacity for Medtronic Inc., Teva Neuroscience, and UCB Pharma. Dr Englert has received research support from Schering-Plough, Schwarz Biosciences, and Teva Neuroscience. Dr. Iyer has received research support from Schering-Plough Corp., Schwarz Biosciences, and Teva Neuroscience. Dr. Conway has received personal compensation for activities with Bayer Pharmaceuticals Corp., Biogen Idec, Teva Neuroscience, EMD Serono, and Pfizer Inc. Dr. Conway has received research support from Eli Lilly & Company, National Institutes of Health, Novartis, EMD Serono, Biogen Idec, the Duke Murdock Study, AB Science, Avanier, Roche Diagnostics Corporation, Genentech Inc., Opexa, and the National Sclerosis Society. Dr. Kaufman has received personal compensation for activities with Acorda Therapeutics, Biogen Idec, Genzyme Corp., Novartis, and Teva Neuroscience. Dr Kaufman has received research support from Eli Lilly & Co., National Institutes of Health, Novartis, EMD Serono, Biogen Idec, Duke Murdock Study, AB Science, Avanir Pharmaceuticals, Roche Diagnostics Corp., Genentech Inc., Opexa, and the National Multiple Sclerosis Society. Dr. Bravver has received research support from Biogen Idec, Avanier, Cytokinetics Pharmaceuticals, Neuraltus Pharmaceuticals, GlaxoSmithKline Inc., the National Institute of Neurological Disorders and Stroke, and the Clinical Research Consortium. Dr. Desai has received personal compensation for activities with Purdue Pharma and UCB Pharma as a speaker. Dr. Russo has received personal compensation for activities with Teva Neuroscience and Biogen Idec as a consultant. Dr. Brooks has received personal compensation for activities with Biogen Idec, Avanir Pharmaceuticals, Acorda Therapeutics, Cytokinetics, Synapse, and the National Institute of Neurological Disorders and Stroke. Dr. Brooks has received research support from Biogen Idec, Avanir Pharmaceuticals, Cytokinetics, Neuraltus Pharmaceuticals, GlaxoSmithKline, Inc., and the National Institute of Neurological Disorders and Stroke.