Abstracts

Rationale: Most of early infantile seizures are acute symptomatic seizures and epilepsies with early infantile onset are relatively rare. The aim of this study is to elucidate seizure types at the onset, evolutions of seizure types and prognoses of epilepsies with early infantile onset. Methods: We retrospectively reviewed charts of patients with epilepsies who started to have seizures before 4 months of age and who were admitted to Nagoya University or affiliated hospitals. We excluded patients with acute symptomatic seizures such as hypoxic-ischemic events, intracranial hemorrhage, meningitis, encephalitis, hypocalcaemia and other electrolyte abnormalities, or hypoglycemia. We also excluded patients with the follow-up period less than 1 year. We divided the patients into three groups: idiopathic group (epilepsies with normal development and unknown etiology), probably symptomatic group (epilepsies with abnormal development and unknown etiology) and symptomatic group (epilepsies with specific etiology). We compared the age of onset, initial seizure types, evolution of seizure types and prognoses among them. Results: Seventy-three patients were studied. Twenty of them were categorized as idiopathic group, 23 were probably symptomatic group and 30 were symptomatic group. Fourteen of the 20 patients in idiopathic group had first seizures during the neonatal period, while first seizures occurred after the neonatal period in 12/23 patients in probably symptomatic group and 22/30 patients in symptomatic group. All patients in idiopathic group had partial seizures (PS) without changes of the seizure types. In probably symptomatic group, the initial seizure types were PS in 20/23 patients, spasms in 2 patients and combination of spasms and PS (spasm+PS) in 1 patient. Three of the 20 patients with PS at the onset evolved to have spasm+PS and 1 patient evolved to have spasms only during the follow-up period. In symptomatic group, 23 /30 patients had PS and 7 patients had spasms as the initial seizures. Seven of 23 patients who had PS as the initial seizures evolved to have spasm+PS and 4 patients evolved to have spasms only during the follow-up period. Twelve of 20 patients in idiopathic group, 4 /23 patients in probably symptomatic group and 1/30 patients in symptomatic group had no seizures after administration of the first antiepileptic drugs. Two of 20 patients in idiopathic group, 12/23 patients in probably symptomatic group and 24/30 patients in symptomatic group did not respond to antiepileptic drugs. Conclusions: Patients with idiopathic epilepsies consistently had partial seizures. In contrast, patients with probably symptomatic and symptomatic epilepsies often showed evolution of seizure types during the follow-up period. The patients in idiopathic group had good response to antiepileptic drugs and most of the patients in symptomatic group had intractable epilepsies.