Electrographic seizures are associated with brain injury in newborns undergoing therapeutic hypothermia.
OBJECTIVE
Seizures are common among newborns with hypoxic-ischaemic encephalopathy (HIE) but the relationship between seizure burden and severity of brain injury among neonates receiving therapeutic hypothermia (TH) for HIE is unclear. We tested the hypothesis that seizure burden is associated with cerebral tissue injury independent of amplitude-integrated EEG (aEEG) background activity.


METHODS
Term neonates undergoing 72 h of TH at four centres were selected for study if they had continuous aEEG and MRI. The aEEG with corresponding 2-channel raw EEG (aEEG/EEG), was classified by severity of background and seizure burden; MR images were classified by the severity of tissue injury.


RESULTS
Of 85 neonates, 52% had seizures on aEEG/EEG. Overall, 35% had high seizure burden, 49% had abnormal aEEG background in the first 24 h and 36% had severe injury on MRI. Seizures were most common on the first day, with significant recurrence during and after rewarming. Factors associated with severe injury on MRI were high seizure burden, poor aEEG background, 10 min Apgar and the need for more than one anticonvulsant. In multivariate logistic regression, high seizure burden was independently associated with greater injury on MRI (OR 5.00, 95% CI 1.47 to 17.05 p=0.01). Neither aEEG background, nor 10 min Apgar score were significant.


CONCLUSIONS
Electrographic seizure burden is associated with severity of brain injury on MRI in newborns with HIE undergoing TH, independent of degree of abnormality on aEEG background. Seizures are common during cooling, particularly on day 1, with a significant rebound on day 4.
Royal London Hospital, , London, UK.
Divyen K
DK
Shah
Courtney J
CJ
Wusthoff
Paul
P
Clarke
John S
JS
Wyatt
Sridhar M
SM
Ramaiah
Ryan J
RJ
Dias
Julie-Clare
JC
Becher
Olga
O
Kapellou
James P
JP
Boardman
D000927:Anticonvulsants / Q000627:therapeutic use; D001034:Apgar Score; D001930:Brain Injuries / Q000209:etiology* / Q000503:physiopathology; D004569:Electroencephalography / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced / Q000009:adverse effects*; D020925:Hypoxia-Ischemia, Brain / Q000150:complications* / Q000473:pathology; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D012640:Seizures / Q000150:complications* / Q000188:drug therapy; D012720:Severity of Illness Index; D013997:Time Factors
D000927:Anticonvulsants
Imaging; Monitoring; Neonatology; Neurology