Natural history of attention deficits and their influence on functional recovery from acute stages to 6 months after stroke

Abstract

Background: Attention deficits are common after stroke, yet their natural course is undefined. This paper examines the course of recovery of attention up to 6 months after stroke. Also examined was the relationship of attention deficits to hemisphere of lesion and to wider outcomes (e.g. quality of life) 6 months after stroke.

Methods: After stroke, 43 individuals completed attention tests (Trails A/B, Paced Auditory Serial Addition Test, Bells Test, Integrated Auditory Visual Continuous Performance Test) at baseline (within 4 weeks after stroke), 6 weeks and 6 months after stroke.

Results: At baseline, 25-60% of attention test scores showed impairment. The sample was significantly disabled (Modified Rankin Scale, MRS), had poor quality of life (36-item short-form questionnaire of the Medical Outcomes Study, SF-36) and significant cognitive difficulties (Cognitive Failures Questionnaire). Visual alternating attention, auditory/visual sustained and alternating attention improved significantly across each time frame. Hemisphere of lesion was not significantly related to baseline attention or to degree of improvement (p > 0.05). However, it was noted that while left-hemisphere stroke was associated with improved Trails A performance at each assessment, right-hemisphere lesions improved from baseline to 6 weeks but declined from 6 weeks to 6 months. Improved physical outcomes (e.g. MRS) at 6 months were predicted from less severe stroke, while an improved SF-36 mental component score was best predicted from age. Cognitive ability was predicted from Trails A attention. While left-hemisphere stroke was associated with improved Trails A performance at each assessment, right-hemisphere lesions improved from baseline to 6 weeks but declined from 6 weeks to 6 months.

Conclusions: The findings suggest that attention deficits, particularly with more complex forms of attention, are common acutely after stroke and that while they improve over time, they have a significant impact on wider aspects of functioning.