Persistent visual deficits in minor ischemic stroke

Background: Compared to more severe presentations, minor ischemic stroke (MIS) remains poorly characterized regarding predictors of long-term outcomes. Particularly there is a need to assess the impact of persistent visual deficits on functional disability in this population. This study aims to compare functional outcomes of MIS between patients with persistent visual deficits (PeVD) and patients without PeVD. Methods: This retrospective single-center cohort study included adult acute ischemic stroke patients who presented to a comprehensive stroke center from 2019 to 2023. MIS was defined as a National Institutes of Health Stroke Scale (NIHSS) score ≤5 on admission and at 24 hours. PeVD was defined as a nonzero visual field NIHSS subscore at 24 hours. The primary outcome was the 90-day modified Rankin Scale (mRS) score. Results: Among 1041 MIS patients, 108 (10.4%) had PeVD. Both median presenting (PeVD+: 2 [IQR 1-4] v. PeVD-: 1 [IQR 0-3], p<0.001) and 24-hour NIHSS (PeVD+: 2 [IQR 1-3] v. PeVD-: 1 [IQR 0-2], p<0.001) were higher in patients with PeVD than those without PeVD. At 90 days, patients with PeVD had higher mortality rate (14.3% vs. 7.8%, p=0.04) and mRS scores (p=0.003). After multivariable regression and sensitivity analyses, 24-hour NIHSS was associated with worse 90-day functional outcomes (p<0.001) while PeVD was not (p=0.21). Conclusion: This study suggests a minority of MIS patients have PeVD, which is associated with stroke severity but not with 90-day functional outcomes. Future studies should evaluate alternative and impactful functional outcome measures not captured by mRS in MIS patients with PeVD.