Dementia Risk Following Ischemic Stroke: A Systematic Review and Meta-Analysis of Factors Collected at Time of Stroke Diagnosis

Background: The majority of stroke cases are ischemic in origin and ischemic stroke survivors represent a high-risk population for progression to dementia. Objective: To determine incidence rates and predictors of dementia after ischemic stroke. Methods: A systematic review and meta-analysis compliant with Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). Results: 5,843 studies were screened for title and abstract. 292 eligible studies were screened for full text. A total of 22 studies met the inclusion criteria and were included, representing 55,929 ischemic stroke survivors. Cumulative incidence of dementia after stroke was 20% at 5 years, 30% at 15 years, and 48% at 25 years of follow-up. Dementia incidence rates were 1.5 times higher among patients with recurrent ischemic stroke compared to patients with first-time stroke. Predictors of dementia after ischemic stroke included female gender (OR 1.2, 95% CI (1.1, 1.4)), hypertension (1.4, (1.1, 2.0)), diabetes mellitus (1.6, (1.3, 2.1)), atrial fibrillation (1.9, (1.2, 3.0)), previous stroke (2.0, (1.6, 2.6)), presence of stroke lesion in dominant hemisphere (2.4, (1.3, 4.5)), brain stem or cerebellum (OR 0.5, (0.3, 0.9)) or frontal lobe (3.7, (1.2, 12.0)), presence of aphasia (OR 7.9, (2.4, 26.0)), dysphasia (5.8, (3.0, 11.3)), gait impairment (1.7, (1.1, 2.7)), presence of white matter hyperintensities (3.2, (2.0, 5.3)), and medial temporal lobe atrophy (3.9, (1.9, 8.3)). Conclusion: Factors routinely collected for stroke patients are a useful resource for monitoring dementia progression in this population. In the present meta-analysis, cardiovascular factors, stroke location, stroke-related disability and chronic brain changes were predictors of dementia after ischemic stroke.