Physical activity is associated with cognitive processing speed in persons with multiple sclerosis.

The impairment of cognitive processing speed is common, disabling, and poorly managed in multiple sclerosis (MS). This study examined the association between objectively-measured physical activity and cognitive processing speed (CPS) in a large sample of persons with MS. Patients (N=212) underwent two valid neuropsychological tests of CPS, completed the Timed 25-Foot Walk (T25FW), and wore an ActiGraph model GT3X accelerometer during the waking hours of a 7-day period for objectively measuring physical activity as steps/day. Physical activity was significantly associated with CPS (r=.39, p<.01), even when controlling for age, sex, and education (pr=.26, p<.01). This association was attenuated, but still significant after further controlling for T25FW performance (pr=.13, p=.03). Physical activity behavior is positively and independently, albeit weakly, associated with CPS in persons with MS, and may play an important role in managing this aspect of cognition as it does in other outcomes in MS.