Attentional deficits in stroke patients: a visual dual task experiment.

OBJECTIVE

(1) To compare the performance of subjects who have suffered a single lateralized cortical, ischemic stroke versus controls on measures of attention including a computerized dual visual attentional task to determine if this task is more sensitive for detecting the presence of subtle hemi-inattention compared to traditional attention tasks; (2) to determine if there is evidence of hemi-inattention in persons who completed spontaneous neurological recovery after a cortical, ischemic stroke compared to controls.

SUBJECTS

Thirty-six patients (N = 20 Right Hemisphere and N = 16 Left Hemisphere) who had previously undergone stroke rehabilitation and who were at least 1 year poststroke. All patients were currently living in the community. A control group of 20 subjects was recruited from the community.

RESULTS

There was no difference in performance between the three groups on gross clinical testing for hemi-inattention, or on the traditional letter-cancellation tasks. All subjects also participated in two computer generated tasks: (1) tracking a moving stimulus and (2) detecting briefly appearing targets. On the single task performance the control group performed significantly better than both cerebrovascular accident (CVA) groups (p < .004), but with no trend for hemi-inattention in any individual group. When the two computer tasks were combined, there was a significant difference in performance between the control group and all stroke subjects (p < .02) for target detection. A fatiguing effect over time was also found in the right CVA group on the dual task. Stroke subjects driving at the time of data collection performed better on the dual attentional task compared to stroke subjects not driving (p = .05).

CONCLUSIONS

On single and dual dynamic computerized visual attentional tasks, individuals who have suffered a cortical stroke more than 1 year before testing have significantly impaired attention compared to controls.