Abstracts

Rationale: To compare epilepsy outcomes and risk factors for epilepsy in infants with HIE with or without TH Methods: This is a cross sectional study of neonates ≥ 36 weeks to 44 weeks who were evaluated by neonatal neurocritical care service from 2004 until 2010. We characterized EEG background patterns and presence of status epilepticus. Follow up data were gathered by a phone survey or by chart review. EEG Background patterns used ACNS terminology described below. Excessive discontinuity is defined as a discontinuous pattern with interburst interval (IBI) amplitude between 5 and 25 µV pp and IBI duration >6sec for 37-40 week PMA and IBI >10sec for 36 week PMA. Burst suppression is an invariant, unreactive pattern in which abnormal bursts of activity are separated by IBI with amplitude <5 µV pp. Low voltage suppressed is defined as an invariant, unreactive pattern with amplitude < 10 and ≥2µV pp Electrocerebral inactivity is defined as activity < 2 µV pp. Status epilepticus is defined as recurrent seizures for ≥50% of a 1 hour EEG epoch Results: During the study period 234 neonates met the inclusion criteria. 68.8% ( 161/234 ) received TH and 31.2% ( 73/234) did not receive TH . We found 9.93%(16/161) in TH group were diagnosed with epilepsy, whereas 16.43% ( 12/73) developed epilepsy in non- TH group, including 1 case of Infantile spasm. The median age of epilepsy onset in TH group was 1.85 years (0.16 -3.9 year). The median age of epilepsy onset in non-TH group was 1.1 years (0 - 6 years). EEG background patterns are presented in the Table. Conclusions: Epilepsy patients, whether they received TH or not, have abnormal EEG background patterns excessively discontinuous, burst suppression , low voltage suppressed or electrical inactivity. Status epilepticus is highly associated with later development of epilepsy. Unlike prior findings, infantile spasm are uncommon in our study.