Clinical, etiological, and therapeutic profile of early-onset absence seizures: A case series analysis

Typical absence seizures represent a distinctive form of epileptic activity typically observed in pediatric populations, predominantly manifesting between the ages of 4 and 10, constituting Childhood Absence Epilepsy (CAE). However, a subset of patients presents with Early-onset Absence Epilepsy (EOAE), characterized by seizure onset before the fourth year of life, often displaying favorable outcomes with antiseizure medication. Conversely, atypical absence seizures exhibit prolonged duration and frequently entail tonic, atonic, or myoclonic motor elements, suggesting a more severe clinical course, commonly associated with epileptic encephalopathies of childhood onset. Recent genetic investigations have highlighted the involvement of specific genes, notably the SLC1A2 mutation, identified in 10 % of EOAE cases, underlying the GLUT1 deficiency syndrome. Timely recognition of such genetic anomalies facilitates tailored interventions, including ketogenic dietary regimes, shown to ameliorate epileptic symptomatology and neurocognitive sequelae. This retrospective study aimed to delineate the distinct features of EOAE and early-onset atypical absence seizures, facilitating prompt diagnosis, particularly emphasizing genetic aberrations, and initiating precision therapeutic approaches to optimize patient outcomes. Evaluation of 23 patients with absence epilepsy onset within the first four years of life, conducted at the Neuropediatrics Outpatient Clinic of the Policlinico of Modena, revealed that children with atypical absences often exhibit a complex clinical and electroencephalographic phenotype, frequently associated with genetic abnormalities. Notably, neurocognitive prognosis appears less favorable in this subgroup, with half of the patients displaying pharmacoresistance. In contrast, all EOAE cases demonstrated seizure freedom, corroborating previous literature suggesting a relatively benign clinical course in these individuals.