Neonatal porencephaly in very low birth weight infants: ultrasound timing of asphyxial injury and neurodevelopmental outcome at two years of age.

OBJECTIVE: To investigate and diagnose the timing of asphyxial injury leading to cerebral cavitation with subsequent developing of neonatal porencephaly in the preterm VLBW infant. All newborns underwent careful neurodevelopmental outcome at 2 years of corrected age.

METHODS: 250 consecutive VLBW infants (mean gestational age of 28 weeks and mean birthweight of 1150 g) have been study by means of weekly neonatal transfontanellae ultrasonography. Periventricular white matter necrosis was diagnosed when echolucencies were visible after day 3 from birth.

RESULTS: Twelve cases of neonatal porencephaly were diagnosed by ultrasound. The timing of asphyxial insult leading to cerebral cavitation seems to have occurred in 33% of neonates during the antepartum period, in 42% during the peripartum period (antepartum + neonatal period) and 25% in the remaining neonatal period. Periventricular-intraventricular hemorrhage (PVH-IVH) was found in all cases and in 50% a severe IVH (grade III-IV) was diagnosed within 7 days neonatal period. Nine infants had evidence of cerebral palsy at 2 years neurological outcome.

CONCLUSIONS: The ultrasound criteria of cerebral cavitation have been priorly selected in order to assure that the damage may have occurred before delivery. A comprehensive prenatal study of fetal brain, integrating ultrasound with high-velocity MRI, is also advocate. This will lead to a more detailed understanding of the underlying cerebral condition that is of critical importance for the clinician in planning the time and mode of delivery and have great deal with further medico-legal consideration.