Association between platelet to white blood cell ratio and post-stroke epilepsy in patients with acute ischemic stroke: a multicenter retrospective cohort study.

BACKGROUND

Post-stroke epilepsy (PSE) is a significant complication following acute ischemic stroke (AIS). The platelet to white blood cell (WBC) ratio (PWR) has emerged as a prognostic marker in stroke populations, but its association with PSE remains unknown. This study investigated the relationship between PWR and PSE incidence in AIS patients.

METHODS

This multicenter retrospective cohort study included 21,459 patients from four hospitals. PWR was calculated as platelet count divided by WBC count. The primary outcome was PSE incidence within 1 year post-stroke. Multivariable logistic regression, restricted cubic spline analysis, and subgroup analyses were performed. Receiver operating characteristic curves and DeLong's test compared the predictive performance of PWR with its individual components.

RESULTS

Higher PWR was independently associated with lower PSE risk [odds ratio (OR) per 1-standard deviation increase: 0.214; 95% confidence interval (CI): 0.186-0.245; p < 0.001]. A dose-response relationship was observed across quartiles (quartile 4 vs. quartile 1: OR 0.033; 95% CI: 0.018-0.059; p for trend <0.001). Restricted cubic spline analysis revealed a significant nonlinear relationship between PWR and PSE risk (p for nonlinearity <0.001). A two-piecewise linear regression model further identified a statistically significant change in slope at an inflection point of 20.31. Subgroup analyses revealed significant interactions for diabetes, carotid plaque, paraventricular involvement, gender, and anterior circulation involvement. PWR demonstrated superior predictive performance (area under the curve: 0.879) compared to platelet or WBC alone.

CONCLUSION

Higher PWR was independently associated with lower PSE risk in AIS patients, with a significant nonlinear relationship. PWR may serve as a simple, inexpensive biomarker for early PSE risk stratification.