Abstracts

Rationale: Seizures & abnormal VEEG finding are seen in the perinatal period with HIE & adversely affect morbidity & mortality. The impact on developmental/neurological outcome is significantly better in moderate HIE. Abnormal EEG may help predict the neurological outcome in infants with moderate HIE who had cooling. Methods: This is a retrospective study from 01/2008-12/2012 at NBIMC. Included are neonates who had therapeutic hypothermia with long term monitoring via standard VEEG. Neurological morbidity was determined by review of high risk f/u clinic from 1-5 yrs of age in study population looking for developmental delay,epilepsy and cerebral palsy.Results: The total number of neonates in NICU during study was 2679. Therapeutic hypothermia was required in 40 neonates. All infants had hypothermia based on the inclusion criteria of weight >1800gms, admission pH of <7, base deficit 16, gestational age >35 wks, 6 hrs of age, APGAR score of <5 at 10 mins, seizures or moderate to severe encephalopathy associated with sentinel event. All infants were cooled to a temperature of 33.5 C with cooling blanket followed by rewarming & had VEEG monitoring from 48-72 hrs during cooling. 23 (58%) infants were transfers from outside hospitals. The time to institution of therapeutic hypothermia ranged from 17 min-6 hrs. 10/40 (25%) infants had mildly abnormal VEEG. 15 (37%) infants had moderate changes including mild background attenuation between 5-10 v while 15(37%) infants had severely abnormal VEEG with inactive flat trace, seizures, burst suppression & severe background attenuation. 5 infants-no neuroimaging. 12/35 (34%) infants had a normal MRI while 23 (66%) infants had an abnormal MRI. 8/40 (20%) infants that underwent therapeutic cooling died. 2 Infants were lost to f/u. All the infants were followed for a period of 6 m.-4 yrs. 17/38 (44%) remaining infants that were f/u were found to be developing normally. 3 infants (8%) had mild developmental delays. 4 (10%) infants had moderate developmental delay with language and cognitive deficits. 1 infant had sensorineural hearing loss and 1 infant had a stroke. 5 infants (12.5%) on f/u were found to have global developmental delay & cerebral palsy and 3 (8%) of these infants continued to be on antiepileptic medication for persistent seizures after 1 year of age. Infants with abnormal neurodevelopmental outcome were retrospectively found to have abnormal VEEG on initial examination & degree of abnormality on VEEG correlated with severity of neurological damage.Conclusions: Therapeutic hypothermia has improved the neurological outcome in the infants with moderate HIE. Infants with moderate HIE show the most improvement in long term neurological outcome. The mortality & incidence of severe developmental delay is unchanged in the infants with severe HIE. There is a need for continued f/u for neurological & developmental assessment of the children who have undergone therapeutic hypothermia in the perinatal period to assess the long term implications of this modality.