The predictive value of early neurological examination in neonatal hypoxic-ischaemic encephalopathy and neurodevelopmental outcome at 24 months

Abstract

Aim: The clinical and electrographic signs of hypoxic-ischaemic encephalopathy (HIE) evolve over the first days of life. We examined the evolution of neurological signs over the first 3 days of life, and determined whether serial administration of the Amiel-Tison Neurological Assessment at Term (ATNAT) would predict neurodevelopmental outcome at 24 months.

Method: Term (>37 wks' gestation) neonates born with suspected HIE between May 2003 and May 2005 in a Cork maternity unit were recruited prospectively. Modified Sarnat grading was assigned. The ATNAT was administered on days 1, 2, and 3 of life and a discharge neurological examination. Time to oral feeding and demographic variables were recorded. Developmental status was assessed using the revised Griffiths Mental Development Scales at 6, 12, and 24 months.

Results: Fifty-seven infants were recruited, with 51 (31 males, 20 females) included for follow-up. Neurological examination evolved and normalized over the first 3 days of life in many cases. At 24 months, 21 children had an adverse outcome, including six deaths. Examination at all time points correlated significantly with neurological outcome at 24 months. The best correlations were found to be (1) neurological examination at discharge (r=0.65, p<0.001), (2) Sarnat grading (r=0.64, p<0.001), and (3) ATNAT on day 3 (r=0.46, p<0.001). The best predictive value was seen with neurological examination at discharge (positive and negative predictive values of 86% and 72% respectively).

Interpretation: Persistence of abnormal neurological signs correlates significantly with adverse outcome. The later a neonatal neurological examination was performed, the better its predictive ability.