Abstracts

Rationale: Childhood absence epilepsy typically occurs in children ages 6 to 12 years old. Early-onset absence is considered rare and there are little reported data on its clinical findings. We retrospectively reviewed children who have been diagnosed with early onset epilepsy and examined their clinical features, treatment and outcomes. Methods: We identified patients from our outpatient epilepsy clinic over the past two years who were diagnosed with absence epilepsy by less than four years of age. The medical records were queried for age of seizure onset, seizure type, neurological exam, MRI findings, EEG, treatment and outcomes. Results: Seventeen patients were identified. Three out of the 17 were excluded due to insufficient follow-up. The patients ages were from 2 years 4 months to 12 years 8 months with six females and eight males. Age of seizure onset ranged from 9 months to 4 years. All had the absence but 3 had additional seizure types, GTC (2), and myoclonic seizures (1). All had a normal neurological exam. Six (42%) had attention/ hyperactivity and two had a language delay. Seven patients had MRI done and 4 were normal and 3 had other findings (1 arachnoid cyst, 1 thick corpus callosum and 1 Chiari 1). Three had lumbar puncture done and one patient was recommended to have SLC2A1 gene testing for GLUT 1 deficiency. Three (21%) patients were on ethosuximide (ETX) monotherapy were seizure free. Two (14%) on ETX initially, required another medication (levetiracetam (LEV) and valproic acid (VPA)) and both became seizure free. Three (21%) failed either 1-2 seizure medications first (two initially thought as focal seizures) and with addition of ETX, 1 became seizure free and 2 had seizure improvement of 75%. Five other patients were treated with multiple medications. Two patients failed 1 medication initially and currently, 1 is on VPA and lamotrigine (LTG) and 1 is currently on VPA alone. Both are seizure free. One patient failed 4 medications and is now on zonisamide, LEV and LTG and is seizure free. Two patients continue to have refractory seizures. One patient is on LEV and LTG (ETX increased his seizures), but possibly has GLUT 1 deficiency. One patient failed multiple medications but had mixed absence and myoclonic seizures. Conclusions: This is our initial review of patients with early onset absence epilepsy. The study showed that all patients had normal neurological examination and neuroimaging study . Only in one patient was the possibility of GLUT 1 deficiency considered based on lumbar tap findings. Majority (57%) of the patients did well on ethosuximide monotherapy or in combination with one other medication. Valproic acid and Lamotrigine are also alternatives. Patients that continued to be refractory have mixed type of seizures or possibly have an underlying GLUT 1 deficiency diagnosis. The study is limited with the number of patients identified. Long term follow of these patients will be done to assess long term treatment response and remission pattern.