Effect of single dose methylphenidate on walking and postural stability under single- and dual-task conditions in older adults--a double-blind randomized control trial.

BACKGROUND Methylphenidate (MPH) action may improve executive function and motor function. Effects of MPH on balance function in older adults were investigated. METHODS A randomized controlled double-blind study examined the effects of a single dose of MPH on gait and postural stability in 30 healthy older adults (mean age = 74.9 ± 5.6) in four task conditions: (a) single task, standing still; (b) dual task, standing still performing a memory task; (c) single task, narrow base walking; and (d) dual task, narrow base walking, performing concurrent cognitive tasks. RESULTS A single dose of MPH improved narrow base walking by reducing the number of step errors and step error rate in both single and dual tasks, with no equivalent improvement in postural stability. CONCLUSIONS A single dose of MPH was able to improve gait function in older adults, especially in complex dual tasks that require higher executive control. This could largely account for the effects of MPH on a sustained attention dual task, but direct effects on the motor system may have also played a role.