August 17, 2009

Do people with MS have a harder time multi-tasking when both motor and cognitive functions are involved? That's the question that a team of researchers sought to answer in a recent study. They put 18 MS subjects and 18 controls through tests involving walking, or performing a cognitive task, or doing both simultaneously. Walking function was measured by walking on a special carpet fitted with electronic sensors to measure speed, swing time, and other parameters. Cognitive function was measured by having the subjects listen to sequences of numbers and then repeat those sequences back. Measurements on these tests when the tasks were conducted simultaneously were then compared to baseline measurements taken when the tasks were performed by themselves. Compared with the controls, the MS group did show a greater decline in performance on both measures in the dual-tasking vs. single-tasking mode.

The decrease in performance when dual-tasking was correlated with self-reported fatigue, as well as with a general cognitive screening measure, but it was not correlated with disease duration or severity. The study couldn't determine the root cause of the dual-tasking impairment, which the authors suggested might be a type of attention deficit or overloading of working memory. Regardless of the underlying cause, the authors suggest that people with MS be aware of this potential problem, particularly since the results imply that walking while performing other tasks might increase the risk of falls.