Aerobic Exercise Improves Fitness and Cognition in Relapsing Remitting Multiple Sclerosis (P2.174)

Abstract

OBJECTIVE: To determine the effects of aerobic exercise on cardiovascular fitness, brain function, and novel MRI markers of mitochondrial function. BACKGROUND: Aerobic exercise increases hippocampal size and improves memory in older adults. Animal models and cross-sectional MS studies of aerobic exercise show improved recovery from relapses and associations with brain substructure volumes. A possible mechanism of action is improved CNS mitochondrial function. We hypothesized that an aerobic exercise intervention would improve fitness, cognition, and fatigue in people with MS. We interrogated the CNS metabolic state using phosphorous MR spectroscopy (31P MRS) to determine CNS mitochondrial function. DESIGN/METHODS: 11 participants with relapsing MS and no walking limitations used a treadmill at target heart rate for 30 minutes, 4 times per week, for 8 weeks under supervision. Prior to and post-intervention, participants underwent VO2Max testing, 7T 31P MRS of brain and tibialis anterior (TA) muscle during exercise, and phlebotomy. Subjects completed walking tests, Modified Fatigue Impact Scale (MFIS), and Symbol Digits Modality Test (SDMT, cognitive processing speed). RESULTS: 10 subjects (9 female, age 44.7+/-9.4 years) completed the protocol. One subject was terminated early for recurrent exercise-induced syncope. Mean disease duration was 14.6 +/-6.5 years, and median EDSS was 3.5 (2.5 - 4.0). Resting heart rate, fat mass, and lean mass improved significantly (all p<0.05), as did systolic BP among pre-hypertensive participants (n=4). Significant improvements in SDMT (+7 points, 15[percnt], p <0.05) and the cognitive component of the MFIS (-3.8 points, 26[percnt], p<0.05) were observed. The phosphocreatine recovery constant of the TA muscle improved significantly (27.9[percnt], p<0.05). Brain 31P MRS results and laboratory analyses of serum inflammatory markers will be presented. CONCLUSIONS: Aerobic exercise improved cardiovascular fitness and cognition in a brief intervention. Aerobic exercise should be considered for cognitive rehabilitation programs. Study supported by: Race to Erase MS Foundation; National MS Society

Disclosure: Dr. Spain has nothing to disclose. Dr. Sammi has nothing to disclose. Dr. Garg has nothing to disclose. Dr. Kingsland has nothing to disclose. Dr. Kuehl has nothing to disclose. Dr. Rooney has nothing to disclose.