Is improvement in impaired cognition and depressive symptoms in post-stroke patients associated with recovery in activities of daily living?

Abstract
Depression and cognitive impairment after stroke are associated with physical functional outcomes, but there are limited data on whether depressive symptoms and cognitive status and improvements independently influence functional status and recovery. In a 6-month prospective cohort study of 141 post-acute stroke patients, demographic and clinical data on admission, and neurological, cognitive, depressive symptoms and functional variables on admission and at 6 months after stroke were measured using the National Institute of Health Stroke Scale (NIHSS), Abbreviated Mental Test (AMT), Geriatric Depression Scale (GDS) and Barthel Index (BI). On multivariate analysis, severe activities of daily living (ADL) dependence at 6 months was significantly less likely associated with higher baseline AMT score denoting better cognitive status (OR=0.68, 95% CI 0.48-0.97 per score point) and with greater AMT change score denoting greater cognitive improvement (OR=0.61, 95% CI 0.41-0.91 per change score point); it was also more likely with higher baseline NIHSS scores denoting severe neurological impairment, (OR=1.74, 95% CI 1.13-2.63 per point score), NIHSS change score [denoting lesser neurological improvement (OR = 1.83, 95% CI 1.13-2.93 per unit change score)], but was not associated with baseline or change scores of GDS. Greater magnitudes of functional recovery [BI change score (standardized beta)] were associated with better baseline depressive symptoms (-0.21) and improvement (-0.31), but not with cognitive status or improvement, in the presence of other significant variables, neurological status (-0.89) and improvement (-0.65), lower baseline physical functional status (-0.85) and younger age (-0.23). These data suggest that improving depressive symptoms in stroke patients may accelerate functional recovery, but the level of physical functioning achieved post-stroke is determined by neurological and cognitive factors, consistent with the evidence that improvement of depressive symptoms through therapeutic intervention is limited by cognitive impairment.