Prognostic Value of Neonatal CT Scans in Asphyxiated Term Babies: Low Density Score Compared with Neonatal Neurological Signs

Abstract

Twenty-five asphyxiated term babies were investigated in order to evaluate the prediction of their neurodevelopmental outcome by means of computerized tomography (CT) as compared to neurological symptoms during the neonatal period. Low density (LD) areas, thought to represent hypoxicischaemic lesions, were assessed quantitatively by means of a LD score based on the extent and degree of LD, the total score ranging from 0-36. Neonatal scans were defined according to the time span elapsed between asphyxia and CT as (1) early CT (day 1-7, n = 15), and (2) intermediate CT (day 9-23: n = 14; day 29: n = 1). The newborns were classified according to the neonatal neurological findings as having mild (n= 8, 32%), moderate (n= 9, 36%), and severe (n = 8, 32%) encephalopathy, following the definition of Sarnat and Sarnat (1976).
Among the twenty-two survivors, the follow-up (mean age 19.2 ± 6.0 mts) revealed fourteen (56%) with normal outcome, two (8%) with transient neurodevelopmental anomalies during the first year, and nine (36%) with permanent abnormalities such as cerebral palsy and/or retardation (mainly global) and/or epilepsy. Early CT scans had no predictive value. Intermediate CT, however, showed distinct variations of LD areas which resulted in an LD score well correlated with the later outcome. In particular, a LD score below 14 characterized every baby who developed normally; a prediction not possible in a reliable way by means of neonatal neurological signs. For all abnormal children, the score correlated with the severity of the later neurodevelopmental disorder, except for one with the latest intermediate CT (day 29).

Key words

Asphyxia - Term newborns - CT - Neurodevelopmental outcome