Seizure burden and neurodevelopmental outcome in neonates with hypoxic-ischemic encephalopathy.
Stevenson, Nathan J.
Murray, Deirdre M.
Murphy, Brendan P.
Ahearne, Caroline E.
Boylan, Geraldine B.
John Wiley & Sons Ltd on behalf of Mac Keith Press
Aim: To examine the relationship between electrographic seizures and long-term outcome in neonates with hypoxic-ischemic encephalopathy (HIE). Method: Full-term neonates with HIE born in Cork University Maternity Hospital from 2003 to 2006 (pre-hypothermia era) and 2009 to 2012 (hypothermia era) were included in this observational study. All had early continuous electroencephalography monitoring. All electrographic seizures were annotated. The total seizure burden and hourly seizure burden were calculated. Outcome (normal/abnormal) was assessed at 24 to 48 months in surviving neonates using either the Bayley Scales of Infant and Toddler Development, Third Edition or the Griffiths Mental Development Scales; a diagnosis of cerebral palsy or epilepsy was also considered an abnormal outcome. Results: Continuous electroencephalography was recorded for a median of 57.1 hours (interquartile range 33.5-80.5h) in 47 neonates (31 males, 16 females); 29 out of 47 (62%) had electrographic seizures and 25 out of 47 (53%) had an abnormal outcome. The presence of seizures per se was not associated with abnormal outcome (p=0.126); however, the odds of an abnormal outcome increased over ninefold (odds ratio [OR] 9.56; 95% confidence interval [95% CI] 2.43-37.67) if a neonate had a total seizure burden of more than 40 minutes (p=0.001), and eightfold (OR: 8.00; 95% CI: 2.06-31.07) if a neonate had a maximum hourly seizure burden of more than 13 minutes per hour (p=0.003). Controlling for electrographic HIE grade or treatment with hypothermia did not change the direction of the relationship between seizure burden and outcome. Interpretation: In HIE, a high electrographic seizure burden is significantly associated with abnormal outcome, independent of HIE severity or treatment with hypothermia.
Hypoxic–ischemic encephalopathy , Electroencephalography , Child neurology , Seizures
Kharoshankaya, L., Stevenson, N. J., Livingstone, V., Murray, D. M., Murphy, B. P., Ahearne, C. E. and Boylan, G. B. (2016) ‘Seizure burden and neurodevelopmental outcome in neonates with hypoxic–ischemic encephalopathy’, Developmental Medicine and Child Neurology, 58(12), pp. 1242-1248. doi: 10.1111/dmcn.13215
©2016 The Authors. Developmental Medicine & Child Neurology published by John Wiley & Sons Ltd on behalf of Mac Keith Press. DOI: 10.1111/dmcn.13215 This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.