Increased risk of stroke after a herpes zoster attack: A population-based follow-up study

BACKGROUND AND PURPOSE-: Varicella zoster virus-induced vasculopathy and postherpes zoster attack stroke syndromes have been reported previously; nevertheless, data regarding the exact prevalence and risk of stroke occurring postherpes zoster attack are still lacking. This study aims to investigate the frequency and risk of stroke after a herpes zoster attack using a nationwide, population-based study of a retrospective cohort design. METHOD-: A total of 7760 patients who had received treatment for herpes zoster between 1997 and 2001 were included and matched with 23 280 randomly selected subjects. A 1-year stroke-free survival rate was then estimated using the Kaplan-Meier method. After adjusting for potential confounders, Cox proportional hazard regressions were carried out to compute the adjusted 1-year survival rate. RESULTS-: Of the sampled patients, 439 patients (1.41%) developed strokes within the 1-year follow-up period, that is, 133 individuals (1.71% of the patients with herpes zoster) from the study cohort and 306 individuals (1.31% of patients in the comparison cohort) from the comparison cohort. The log rank test indicated that patients with herpes zoster had significantly lower 1-year stroke-free survival rates than the control (P