Early onset absence epilepsy with onset in the first year of life: a multicenter cohort study

Purpose: Absence epilepsy with onset before age 4 years, or early onset absence epilepsy (EOAE), has been rarely reported, and children with onset in the first year of life are considered almost exceptional. We aimed to report the clinical and electrophysiologic features of a cohort of children with absence epilepsy starting within the first year of life.

Methods: This was a multicenter study including patients with absence epilepsy starting within the first year of life and identified over a 20-year period (1991-2011).

Key findings: We identified 16 patients with absence epilepsy starting within the first year of life with a mean follow-up of 6.4 years. Mean age at seizure onset was 10.3 ± (standard deviation)1.4 months (range 8-12). Two patients experienced rare tonic-clonic seizures that started later than the absences. None of the subjects had episodes of absence status epilepticus. Eleven subjects were seizure-free with the first antiepileptic drug. In eight children, therapy was withdrawn after a mean 3.2 years of treatment. None evolved into a different form of idiopathic generalized epilepsy. SLC2A1 gene analysis in 12 children (75%) failed to reveal glucose transporter 1 deficiency.

Significance: EOAE, including patients with onset within the first year of life, should be no more considered a distinct idiopathic generalized epilepsy (IGE) syndrome, as it shows electroclinical features, response to therapy, and prognosis similar to childhood absence epilepsy. Moreover, early age of onset is not predictive of GLUT-1 deficiency and genetic analysis may be therefore avoided in patients meeting strict inclusion criteria.