Neuroradiologic findings in children with renal transplantation under 5 years of age.

Chronic renal failure (CRF) is known to have adverse effects on the neurodevelopmental outcome of affected children. Some of these effects can be ameliorated by transplantation (TX). The cause and nature of the underlying brain injury is not known. We performed a brain magnetic resonance imaging (MRI) study on a group of children after TX to look for brain abnormalities and, if possible, to draw conclusions about their origin. Thirty-three children who received a renal allograft before 5 yr of age were studied. The most common diagnosis was the congenital nephrotic syndrome of Finnish type (29 patients). The male/female ratio was 22/11, the age range 6-11 yr. Pre-TX CT studies of 26 patients were available for comparison. The patient files were studied for relevant clinical history, including pre- and perinatal events, infections, hypertension, hypertensive crises, hypovolemic states and medical emergencies. These risk factors were correlated with the MRI findings. Eighteen patients (54%) had ischemic lesions in the vascular border zones. Mild lesions were seen in 10 patients, moderate in six and severe in two patients. Other findings were rare, including infarcts in the main vascular territories and basal ganglia, and central and cortical atrophy. The pre-TX CT's revealed border zone infarcts in six patients. Hemodynamic crises were reported in 14 patients and correlated well with border zone infarcts. The age at TX was greater and the duration of dialysis longer in those with border zone infarcts than in those without. Low gestational age, perinatal complications, and septic infections were not statistically significant risk factors. Because of the lack on serial imaging studies we do not know the exact timing of these brain infarcts. The good correlation to pre-TX hemodynamic crises seems, however, to indicate that most of these lesions could be prevented by careful clinical monitoring and early TX.