Ability of early neurological assessment and continuous EEG to predict long term neurodevelopmental outcome at 5 years in infants following hypoxic-ischaemic encephalopathy

O'Connor, Catherine M.

Restricted to everyone for one year. Restriction lift date: 2021-11-12T10:32:24Z

Ability of early neurological assessment and continuous EEG to predict long term neurodevelopmental outcome at 5 years in infants following hypoxic-ischaemic encephalopathy

dc.check.chapterOfThesis	6
dc.check.date	2021-11-12T10:32:24Z
dc.check.embargoformat	Apply the embargo to the e-thesis on CORA (If you have submitted an e-thesis and want to embargo it on CORA)	en
dc.check.info	Restricted to everyone for one year	en
dc.check.opt-out	Not applicable	en
dc.check.reason	This thesis contains data which has not yet been published	en
dc.contributor.advisor	Murray, Deirdre M.	en
dc.contributor.advisor	Boylan, Geraldine B.	en
dc.contributor.author	O'Connor, Catherine M.
dc.contributor.funder	Health Research Board	en
dc.date.accessioned	2019-11-13T10:32:24Z
dc.date.issued	2018
dc.date.submitted	2018
dc.description.abstract	Hypoxic-ischaemic encephalopathy (HIE) symptoms evolve during the first days of life and their monitoring is critical for treatment decisions and long-term outcome predictions. This thesis aims to report the five-year outcome of a HIE cohort born in the pre-therapeutic hypothermia era and to evaluate the predictive value of (a) neonatal neurological and EEG markers and (b) development in the first 24 months, for outcome. Methods: Participants were recruited at age five from two birth cohorts; HIE and Comparison. Repeated neonatal neurological assessments using the Amiel-TisonNeurological-Assessment-at-Term, continuous video EEG monitoring in the first 72 hours, and Sarnat grading at 24 hours were recorded. EEG severity grades were assigned at 6, 12 and 24 hours. Development was assessed in the HIE cohort at 6, 12 and 24 months using the Griffiths Mental Development (0-2) Revised Scales. At age five, intellectual (WPPSI-IIIUK scale), neuropsychological (NEPSY-II scales), neurological and ophthalmic testing was completed. Results: 5-year outcomes were available for 81.5% (n=53) of HIE and 71.4% (n=30) of Comparison cohorts. In HIE, 47.2% (27% mild, 47% moderate, 83% severe Sarnat), had non-intact outcome vs. 3.3% of the Comparison cohort. Non-intact outcome rates by 6-hour EEG-grade were: grade0=3%, grade1=25%, grade2=54%, grade3/4=79%. In HIE, processing speed (p=0.01) and verbal short-term memory (p=0.005) were below test norms. No significant differences were found in IQ, NEPSY-II or ocular biometry scores between children following mild and moderate HIE. Median IQ scores for mild (99(94-112),p=grade 2) at 24hours had superior positive predictive value (74%; AUROC(95%CI)=0.70(0.55-0.85) for non-intact 5-year outcome than abnormal EEG at 6 hours (68%; AUROC(95%CI)=0.71(0.56-0.87). Within-child development scores were inconsistent across the first 24 months. Although all children with intact 24-month Griffiths quotient (n=30) had intact 5-year IQ, 8/30 had non-intact overall outcome. Conclusion: Predictive value of neonatal neurological assessments and an EEG grading system for outcome was confirmed. Intact early childhood outcomes post-HIE may mask subtle adverse neuropsychological sequelae into the school years. This thesis supports emerging evidence that mild-grade HIE is not a benign condition and its inclusion in studies of neuroprotective treatments for HIE is warranted.	en
dc.description.status	Not peer reviewed	en
dc.description.version	Accepted Version
dc.format.mimetype	application/pdf	en
dc.identifier.citation	O'Connor, C. M. 2018. Ability of early neurological assessment and continuous EEG to predict long term neurodevelopmental outcome at 5 years in infants following hypoxic-ischaemic encephalopathy. PhD Thesis, University College Cork.	en
dc.identifier.endpage	300	en
dc.identifier.uri	https://hdl.handle.net/10468/8996
dc.language.iso	en	en
dc.publisher	University College Cork	en
dc.relation.project	Health Research Board (HRB RP/2008/238; HRB CRT/2008/31)	en
dc.rights	© 2018, Catherine M. O'Connor.	en
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/3.0/	en
dc.subject	Sarnat grade	en
dc.subject	Hypoxic-ischaemic encephalopathy	en
dc.subject	Neonatal encephalopathy	en
dc.subject	Neonatal EEG	en
dc.subject	Neurodevelopment	en
dc.subject	Childhood outcome	en
dc.subject	Neuropsychology	en
dc.thesis.opt-out	false
dc.title	Ability of early neurological assessment and continuous EEG to predict long term neurodevelopmental outcome at 5 years in infants following hypoxic-ischaemic encephalopathy	en
dc.type	Doctoral thesis	en
dc.type.qualificationlevel	Doctoral	en
dc.type.qualificationname	PhD	en
ucc.workflow.supervisor	d.murray@ucc.ie