Acutely and retrospectively diagnosed perinatal stroke: a population-based study.

BACKGROUND AND PURPOSE: There are not very many epidemiological studies on perinatal stroke, and many authors suggest that this may be an underdiagnosed condition. The aim of the study was to estimate the incidence of perinatal arterial ischemic and hemorrhagic stroke in Estonia, to study the first clinical signs and to identify possible differences in predisposing factors and outcome between acutely and retrospectively diagnosed cases of perinatal stroke. METHODS: A retro- and prospective study of acutely (within the first month) and retrospectively diagnosed ischemic and hemorrhagic cases of perinatal stroke was conducted in a children population born in the eastern and southern regions of Estonia during the years 1994 to 2003. Patients were identified from a pilot study, hospital records, and an inquiry of child neurologists and general practitioners. The diagnosis was confirmed in 38 (12 were diagnosed acutely and 26 retrospectively) cases by neuroradiology (MRI or CT). RESULTS: The incidence rate of perinatal stroke in Estonia is 63 per 100,000 live births. Main clinical findings in the neonatal period were seizures, abnormalities of muscular tone, and disturbed level of alertness. Previously identified risk factors occurred in 32% of cases. Children with early diagnosis had more often adverse events during pregnancy and delivery (P<0.05) and developed more severe stage of hemiparesis compared with children with late diagnosis (P<0.05). CONCLUSIONS: The incidence rate of 63 per 100,000 live birth is higher than previously reported. Detailed analysis of the first signs of perinatal stroke may improve the early diagnostics of perinatal stroke.