Background: Leukoaraiosis (LA) is closely associated with cognitive deficits. The association between LA and cognitive disorders, such as mild cognitive impairment (MCI) and dementia, after initial stroke has not been systematically studied. In this study, we sought to identify whether LA contributes to the occurrence of certain type of cognitive disorders after initial stroke.
Methods: Data from our Stroke Registry were examined, and 5-year follow-up data for LA and cognitive disorders were analyzed. We performed Kaplan-Meier analysis and log-rank test to assess the predictive value of LA for risk of cognitive decline and the Cox proportional hazards model to test the risk factors studied as independent determinants of cognitive impairment.
Results: The frequency of patients with normal cognitive function decreased significantly at 5 years compared with initial stroke (78% vs 70%; odds ratio, 1.51; 95% confidence interval, 1.41-1.62). Of 8784 patients, 1659 (19%) had dementia and 964 (11%) had MCI at the final analysis. After 5 years of follow-up, survival analysis showed that all patients with LA had an increased probability of MCI compared with those without LA (P < .0001). Patients with LA had an increased chance of dementia compared with those without LA (P < .0001) at the end of follow-up. Cognitive decline probability was significantly higher in patients with severe LA compared with those with mild/moderate LA (P < .0001). Cox regression analyses showed that recurrence of stroke (hazard ratio [HR], 3.92 [95% CI, 3.26-4.72]), hypertension (HR, 1.11 [95% CI, 1.0-1.22]), LA (HR, 1.15 [95% CI, 1.05-1.25]), age (HR, 1.05 [95% CI, 1.04-1.06]), hypercholesterolemia (HR, .86 [95% CI, .77-.95]), higher LDL cholesterol (HR, 1.21 [95% CI, 1.11-1.32]), lower HDL cholesterol (HR, .90 [95% CI, .83-.98]), coronary heart disease (HR, .85 [95% CI, .77-.94]), and National Institutes of Health Stroke Scale score at admission (HR, .77 [95% CI, .72-.82]) were also significantly associated with cognitive impairments.
Conclusions: Our findings suggest that patients with LA may be at risk of developing new cognitive impairments at long-term period after initial stroke. The evaluation of the concomitant risk factors, besides providing insights about the possible mechanisms behind the cognitive dysfunction present in LA, may be of help for the prevention of cognitive impairments.
Keywords: Leukoaraiosis; cognitive disorders; mild cognitive impairment; vascular dementia.
Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.