Association of Cortical Superficial Siderosis with Post‐Stroke Epilepsy

Abstract

Objective To assess whether post‐stroke epilepsy (PSE) is associated with neuroimaging findings of hemosiderin in a case–control study, and whether the addition of hemosiderin markers improves the risk stratification models of PSE. Methods We performed a post‐hoc analysis of the PROgnosis of POST‐Stroke Epilepsy study enrolling PSE patients at National Cerebral and Cardiovascular Center, Osaka, Japan, from November 2014 to September 2019. PSE was diagnosed when one unprovoked seizure was experienced >7 days after the index stroke, as proposed by the International League Against Epilepsy. As controls, consecutive acute stroke patients with no history or absence of any late seizure or continuing antiseizure medications at least 3 months after stroke were retrospectively enrolled during the same study period. We examined cortical microbleeds and cortical superficial siderosis (cSS) using gradient‐echo T2*‐weighted images. A logistic regression model with ridge penalties was tuned using 10‐fold cross‐validation. We added the item of cSS to the existing models (SeLECT and CAVE) for predicting PSE and evaluated performance of new models. Results The study included 180 patients with PSE (67 women; median age 74 years) and 1,183 controls (440 women; median age 74 years). The cSS frequency was higher in PSE than control groups (48.9% vs 5.7%, p < 0.0001). Compared with the existing models, the new models with cSS (SeLECT‐S and CAVE‐S) demonstrated significantly better predictive performance of PSE (net reclassification improvement 0.63 [p = 0.004] for SeLECT‐S and 0.88 [p = 0.001] for CAVE‐S at the testing data). Interpretation Cortical superficial siderosis was associated with PSE, stratifying stroke survivors at high risk of PSE. ANN NEUROL 2023;93:357–370

Outcomes in Patients With Poststroke Seizures

“…The articles included 1967 patients (9.8%) with early seizures and 10 605 patients (52.7%) with late seizures after stroke; 7538 seizures (37.5%) were not classified as early or late. PSS were diagnosed according to clinical or medical chart data in 59 studies and using the ICD-10 codes in 12 studies (including 15 033 patients [74.8%]). Patients with PSS had a significantly higher history of ischemic heart disease (OR, 1.3; 95% CI, 1.1-1.6), prior cerebrovascular disease (OR, 1.3; 95% CI, 1.0-1.6), atrial fibrillation (OR, 1.2; 95% CI, 1.1-1.4), and the presence of hemorrhagic transformation (OR, 2.2; 95% CI, 1.6-3.0) than patients without PSS (eTable 3 in Supplement 1).…”

“…Five studies (7.0%) had a high risk of bias, 35 studies (49.3%) presented a moderate risk of bias, and 31 studies (43.7%) had a low risk of bias (eTable 4 in Supplement 1).…”

“…Statistical analyses were appropriate in 44 studies (62%) . Confounding factors were identified in 58 studies (81.7%) and were adjusted in the statistical analysis in 53 studies (74.6%) . Only 37 studies (52.1%) provided complete follow-up data.…”

“…Confounding factors were identified in 58 studies (81.7%) and were adjusted in the statistical analysis in 53 studies (74.6%) . Only 37 studies (52.1%) provided complete follow-up data. The outcomes were measured validly and reliably in 53 studies (74.6%) …”

“…Only 37 studies (52.1%) provided complete follow-up data. The outcomes were measured validly and reliably in 53 studies (74.6%) …”