Changes in postural control in hemiplegic patients after stroke performing a dual task.

Objective: To determine the effects of an attentional task on hemiplegic patients' postural control performances.

Design: Retrospective study.

Setting: Department of physical and rehabilitation medicine at a university hospital.

Participants: Twenty-three hemiplegic patients and 23 healthy age- and sex-matched control subjects.

Interventions: Not applicable.

Main Outcome Measures: Sway area and sway path of the center of pressure were measured during 30 seconds in standing subjects and patients under 3 conditions: eyes open (EO), EO while performing a simple arithmetic task (EO-AT), and eyes closed (EC).

Results: In the hemiplegic patients, the body sway area increased significantly with EC (P<.001) and during the EO-AT task (P<.017) in comparison with EO. Sway area with EO-AT remained, however, significantly smaller than with EC (P<.014). In the healthy subjects, the body sway did not differ significantly between the EO-AT and EO tasks (P<.42). The increase observed in the sway area and path in the hemiplegic population during the EO-AT task correlated significantly with age.

Conclusions: The postural performances of hemiplegic patients decreased during both the arithmetic task and the EC task. The cognitive task had no effect on healthy subjects' postural performances. This study is the first to show the combined effects of age and dual task on the postural performances of hemiplegic subjects.