Abstracts

Rationale: Seizures are symptoms of various neurological conditions. Overall, 40-50% of untreated individuals can be expected to have a recurrence within 2 years after the first seizure. EEG and etiology are consistently found to be the best predictors for seizure recurrence and prognosis. This study aimed to find the predictors for seizure recurrence in developmentally and neurologically normal children who had a newly diagnosed, unprovoked seizure. Methods: The medical record was retrospectively reviewed in 393 children who had a newly diagnosed, unprovoked seizure by using the standardized data collection form at the Pediatric New Onset Seizure Clinic of Emory University between August 2011 and July 2013. One hundred sixty-one cases (70.6%) were referred from hospital emergency centers. Exclusion criteria include children with (1) absence or myoclonic seizures (n=25) (2) history of prematurity (gestational age ≤ 36 weeks, n=54) (3) chromosomal abnormality or genetic disorder (n=18) (4) known history of structural brain lesion, shunted hydrocephalus, traumatic brain injury, meningoencephalitis, hypoxic ischemic encephalopathy, static encephalopathy or autism (n=45) (5) delayed development or speech delay (n=17) and (6) diabetes mellitus or organ transplantation (n=6). A total of 228 children met the inclusion criteria. The number of seizures was counted as one in case of more than 2 seizures in 24 hours. The relation between seizure recurrence and predictable variables, such as abnormal EEG, abnormal MRI, number of seizures before the first clinic visit, positive family history, and neurologic comorbidity, was examined through linear probability model by using SPSS^® v21. Results: Mean age was 7.5 year at the first clinic visit. The first seizure was described as generalized tonic-clonic seizure in 169 cases (74.1%), dyscognitive seizures in 34 cases (14.9%), and focal motor seizures in 25 cases (11.0%). EEG was abnormal in 102 out of 218 cases (46.8%); focal epileptiform abnormality in 58 cases (26.6%) and generalized epileptiform abnormality in 33 cases (15.1%). Brain MRI revealed the structural abnormality in 24 out of 135 cases (13.8%) and significant focal structural lesion in 9 cases including 3 FCD, 1 Encphalomalacia, 1 MTS, 1 Tubers, 2 ganglioglioma, and 1 Neurocysticercosis. One hundred seventy-three cases (75.9%) had follow-ups and 122 cases (53.5%) experienced recurrent seizures over the mean follow-up duration of 15.3 months. Children with abnormal EEG or ≥ 4 seizures before the first clinic visit are more likely to have recurrent seizures compared to those with normal EEG or < 4 seizures, respectively. Conclusions: Abnormal EEG findings and ≥ 4 seizures before the first clinic visit predict seizure recurrence after a single unprovoked seizure. Brain MRI was not high-yield for finding the significant focal structural lesion.