Cognitive impairment in patients with acute ischemic stroke after mechanical thrombectomy

Background: Post-stroke cognitive impairment is associated with increased mortality and healthcare costs. However, its characteristics in patients with large vessel occlusion after mechanical thrombectomy (MT) remain unclear. In this study, we aimed to evaluate the feasibility of administering the Montreal Cognitive Assessment (MoCA) in the acute phase after MT and examine its association with long-term cognitive outcomes. Methods: We retrospectively analyzed patients with acute ischemic stroke who underwent MT and completed MoCA within five days of admission, using data from a prospective registry. Patients were classified into acute MoCA feasible and non-feasible groups. Clinical characteristics and cognitive outcomes were compared between the groups, including MoCA and modified Rankin Scale (mRS) scores post-MT. Results: In total, 161 patients were enrolled: 77 (median age, 73 years; 56 men) in the feasible group and 84 (median age, 77 years; 50 men) in the non-feasible group. Multivariate analysis showed that higher National Institute of Health Stroke Scale score on admission (OR 1.09, 95% CI 1.03–1.14; p<0.01) and left-sided occlusion (OR 2.17, 95% CI 2.17–4.00, p=0.01) were independently associated with MoCA feasibility. Among 51 patients assessed at six months, over 80% had persistent cognitive impairment. The chronic MoCA score in the feasible group was 24 and in the non-feasible group was 17. Both groups achieved a favorable functional outcome (mRS score ≤ 2). Conclusion: Over 80% of patients with acute ischemic stroke who underwent MT experienced chronic cognitive impairment, even among those with favorable functional outcomes.