[Epidemiological study of cerebral palsy in Shiga Prefecture, Japan, during 1977-2000. Part 2: etiologies and risk factors of cerebral palsy in Shiga prefecture].

Etiologies and risk factors of 569 patients with cerebral palsy (CP) in Shiga Prefecture born during 1977-2000 were investigated. The patients with CP born at preterm and at term were separately analyzed. The main etiologies or risk factors for CP in preterm children were periventricular leukomalacia (PVL, 58%), multiple births (25%) and mechanical ventilation (45%). The prevalence rates of these increased in the latter half of the study period. The main etiologies or risk factors for CP in term children were brain dysplasia (17%), fetal brain vascular disorders (15%), hypoxic ischemic encephalopathy (14%), PVL (8%) and intrauterine growth retardation (19%). The prevalence rates among etiologies did not change during the study period.