Purpose: To evaluate the value of magnetic resonance imaging (MRI) in the visual prognosis of cortical visual impairment following perinatal hypoxia.
Methods: MRI findings of 19 babies with the diagnosis of a perinatal hypoxic-ischemic insult and cortical visual impairment (CVI) were reviewed. Two groups of patients based on gestational age were compared. Babies with a gestational age > or = 34 weeks were included in group 1(n = 8). Infants < 34 weeks' gestation were included in group 2(n = 11). All 19 children underwent MRI.
Results: Normal MRI always correlated with better visual outcome, regardless of the gestational age at which the insult occurred. Among infants born at or later than 34 weeks' gestation, a favorable visual recovery occurred in two with normal MRI findings. The presence of infarcts or periventricular leukomalacia indicated that full visual recovery would not occur. Among infants born before 34 weeks' gestation, the MRI findings were normal in two who had a favorable visual outcome. A normal visual cortex and the absence of periventricular leukomalacia were helpful in prognosticating the visual outcome. A general delay in the myelination-particularly in the myelination of the optic radiation-was a common finding and until now has not been described in children with CVI routinely.
Conclusion: MRI's ability to follow the process of myelination may be of predictive value. MRI, therefore, should be obtained in a child with CVI following perinatal hypoxia.