Motor and cognitive functions are interrelated in people with multiple sclerosis (MS), according to a recent study, and it is speculated that neural damage in people with MS impairs both cognitive processing speed and gait control. This investigation determined whether cognitive function, as measured by processing speed, is associated with gait variability in individuals with MS. This secondary analysis included 191 individuals with MS who underwent gait assessment and cognitive assessment. Cognitive processing speed was indexed by symbol digit modalities test (SDMT). Gait variability was indexed by step length and step time coefficient of variation (CV). Hierarchical linear regressions were performed to examine whether SDMT scores would predict step length and step time CV. Researchers found:

• After adjusting for age, gender, and disability, it was found that SDMT was a significant predictor of step time CV and step length CV.
• Overall, slower cognitive processing speed was significantly associated with greater gait variability.