CEREBRAL MRI OF VERY-LOW-BIRTH-WEIGHT CHILDREN AT 6 YEARS OF AGE COMPARED WITH THE FINDINGS AT 1-YEAR

Background. We have previously reported the results of cerebral MRI ex aminations in an unselected year cohort of very low birth weight (VLBW ) infants at one year of corrected age. Twenty-one (78 %) of 27 infant s had abnormal myelination, mainly in the central occipital white matt er (COWM) and in the centrum semiovale (CS), seen on T2-weighted image s. Twelve infants had irregular and dilated lateral ventricles. We spe culated whether these findings indicated perinatal periventricular leu komalacia (PVL). Only two infants had completely normal MRI at age 1 y ear. Objective. To determine whether the abnormal myelination seen at 1 year of age, was still present, either as delayed myelination or as gliosis caused by perinatal PVL. Materials and methods. In the present study, we report the results of follow-up cerebral MRI in 20 of these infants at 6 years of age. Results. Most of the children with MRI dev iations at 1 year still had abnormalities at 6 years. Abnormal myelina tion in the central occipital white matter combined with abnormalities in the CS or with ventricular dilatation at age 1 year, presented as gliosis in 12 of 13 children at 6 years of age. Abnormalities solely i n the COWM at age 1 year had normalised in two of five children and pe rsisted as delayed myelination in three at age 6 years. Gliotic change s in periventricular white matter were found in 12 of 20 children (60 %). Areas most affected were the CS (11 children) and the COWM (9 chil dren). Delayed myelination in COWM was found in six children (30 %), c ombined with gliosis in CS in three children. Twelve infants had ventr icular dilatation both at 1 and 6 years of age. Conclusions. The MRI c orrelates of PVL, i. e. gliosis and ventricular dilatation, are common findings on cerebral MRI at 6 years of age in VLBW infants.