Attentional demands for static postural control after stroke

Objective: To assess the attentional demands associated with postural control among people who have had a stroke. Design: Nonrandomized matched case-control study. Setting: University research laboratory in Canada. Participants: Six individuals who had suffered a left or right cerebral ischemic attack in the past year and a sample of 6 age-and gender-matched controls. Participants in the stroke group had a mean age of 64.17+/-13.14 years; control participants had a mean age of 64.00+/-13.91 years. Mean National Institute of Health Stroke Scale scores for these patients were 7.67+/-4.92 at the time of stroke and 1.66+/-1.36 at the time of testing. None of the patients were taking medications that would alter cognitive status or balance abilities. Intervention: Participants performed a verbal reaction-time test while engaged in 3 postural tasks (sitting, standing, standing with feet together). Main Outcome Measure: Reaction time: latency between visual stimulus and verbal response. Results: Reaction times in the stroke group differed significantly in all conditions from the controls (410+/-72ms vs 320+/-54ms, P<.01). A significant interaction was found between group and postural task (P=.05), with reaction-time scores showing a progressive increase, in postural task difficulty among participants who had suffered a stroke. Post hoc comparisons revealed that sitting reaction-time scores were significantly slower than reaction-time scores for feet together standing (P=.009) among participants in the stroke group. Conclusion: Individuals who have suffered a stroke showed increased attentional demands for tasks of static postural control compared with healthy, age-matched participants. (C) 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation.