Absence Epilepsy with Onset before Age Three Years: A Heterogeneous and Often Severe Condition

Abstract
Summary: Purpose: The classification of epilepsies and epileptic syndromes recognizes three syndromes with typical absences [TA, i.e., childhood and juvenile absence epilepsies (CAE and JAE), and epilepsy with myoclonic absences (EMA), none of which is characterized by onset in early childhood]. Although several other forms of absence epilepsies have been described recently, none concerns infants and very young children, and little is known about the nosology and prognosis of early‐onset absences. Methods: We retrospectively selected all cases with onset of absences as the only or major seizure type before age 3 years and ≥2 years of follow‐up among cases newly referred between 1986 and 2002. Neurospychological assessments (generally IQ measure), behavior patterns, and schooling situations were reviewed for each child. Results: We found 10 patients (7 F, 3 M). No child had sensory or motor deficits: neuroimaging was performed in nine and was normal in eight, with aspecfic findings in one. Only two could be characterized as CAE and EMA, respectively, both with seizure control and a good cognitive outcome. Among the remaining eight cases, four had a fairly homogeneous presentation with predominantly brief absences and clearly asymmetric interictal EEGs. All eight had neuropsychological and/or behavioral difficulties. Three had full seizure control, and five, persisting absences, with a follow‐up ranging beetween 2 years 8 months to 9 years 4 months; only one child was older than 12 years. Conclusions: Great heterogeneity exists among absence epilepsies of early onset, which are rare conditions. Only a few patients can be categorized into well‐known syndromes. The overall prognosis is poor. Early onset of absences is uncommon, and multicenter studies should help clarify the nosology and prognosis.