NATIONAL SURVEY OF PERIVENTRICULAR LEUKOMALACIA IN JAPAN

Background: Clarification of the present status of periventricular leu komalacia (PVL) in Japan. Methods: Questionnaires were mailed to the l eading neonatal intensive care units (NICU) and rehabilitation centers for children. Results: The incidence of PVL in the group of surviving preterm infants of gestational ages less than 33 weeks was 4.8-4.9% o n ultrasound and 7.7-7.9% on magnetic resonance imaging and/or compute d tomography. The incidence of PVL did not decrease between 1990 and 1 994. The incidence of PVL in the NICU varied from 0 to 47.1%. Infants from multiple pregnancies had a higher incidence (9.1%) of PVL than th ose from single pregnancies (6.2%). The proportion of PVL in all patie nts in rehabilitation centers with cerebral palsy (CP) has increased r ecently. Conclusions: It was roughly calculated that about 750 cases o f CP with PVL occurred annually in Japan, thus accounting for about on e-third of the total number of cases of CP.