Cerebral magnetic resonance imaging and ultrasonography findings after neonatal hypoglycemia

Objective. The aim of this study was to investigate sequential neuroradiolo gic changes in the brains of infants after transient neonatal hypoglycemia. We used magnetic resonance imaging (MRI) and ultrasonography (US) head sca ns. Methods. Eighteen symptomatic full-term infants whose serum glucose concent rations were less than or equal to 45 mg/dL (2.5 mmol/L) without any other diseases were included in the hypoglycemic group. MRI and US head scans wer e performed at full-term age and at the age of 2 months. The imaging result s were compared with the findings of MRI and US scans in 19 healthy normogl ycemic term newborn infants at the respective ages. The neurologic outcome was followed in the both groups. Results. MRT or US showed evidence of abnormality in 39% the hypoglycemic i nfants. MRI detected more abnormalities in the brains than US. Four infants showed patchy hyperintensity lesions either in the occipital periventicula r white matter or the thalamus on T1-weighted images. These lesions had a g ood tendency to recover and only 1 of these infants appeared to be neurolog ically affected. Of the 19 controls, 10% (2 of 19) had caudothalamic cysts, which were detected both with MRI and US. The relative risk of the hypogly cemic child compared with nonhypoglycemic child, to have any abnormality de tected in the brain, was 3.7, with a 90% confidence interval from 1.11 to 1 2.28. Conclusions. postnatal full-term MRI and US scans showed abnormalities four times more often after transient neonatal hypoglycemia than in the healthy control group. However, most often lesions were absent 2 months later. The clinical relevance of these abnormal findings remains to be clarified with detailed neurologic examinations and follow-up.