Abstracts

Rationale: Many patients presenting with convulsive status epilepticus (CSE) have no prior history of seizures. Few studies have investigated the characteristics of CSE as the first identified seizure focusing specifically on pediatric population. The aim of this study was investigate the demographic and clinical characteristics of pediatric patients with an initial seizure presentation of CSE. We compared this population to patients presenting with CSE with a pre-existing seizure history.Methods: We retrospectively studied pediatric patients admitted to Boston Children’s Hospital with at least one episode of CSE between January 1, 2005 and December 31, 2010. A 5-minute cut-off was used as the operational definition of CSE. Inclusion criteria were: (1) age of 1 month to 21 years at the time of CSE, (2) convulsive seizures at the beginning of CSE. The exclusion criteria were: (1) Exclusively electrographic SE without a convulsive correlate, (2) psychogenic non-epileptic seizures or seizures of unclear epileptic nature, (3) incomplete or unclear information regarding duration of seizure, (4) incomplete or unclear information regarding prior seizure history. Patients were categorized into two groups: new onset CSE (CSE as the initial identified seizure activity) and pre-existing seizure history.Results: We found 461 patients that fit our criteria, 81 (17.6%) presented as new onset CSE. Out of the 81 new onset CSE subjects, 44 (54.3%) were female, the median age was 3.5 years (IQR 1.08-6.83), 30% being ≤ 18 months and 68.8% being ≤6 years old. Median duration of CSE was 20 minutes (IQR 10-40), and 40.7% had duration of 30 minutes or more. New onset CSE presented with fever in 66.7% of cases. Central nervous system infection accounted for 12.9% of febrile cases. MRI was normal in 51.9% cases, and 22.2% had normal EEG. The majority of patients (74.1%) had normal development prior to CSE onset. There were three deaths (3.7%) among new onset CSE patients. New onset CSE patients were younger than those with pre-existing seizure history (4.96 ± 4.71 years vs. 7.48 ± 5.61 years, p<0.001) and presented with fever more often than the subjects with a pre-existing seizure history (66.6% vs. 16.1%, p<0.001) (Table 1). While the majority of new onset CSE patients were developmentally normal, a large number of the patients with prior history of seizure was developmentally delayed (25.9% vs. 65.3% delayed, p<0.001).Conclusions: New onset CSE occurred in younger patients and presented with fever more frequently than patients with pre-existing seizure history. Fewer new onset CSE patients had a developmental delay compared to those with pre-existing seizure; however, development was not followed longitudinally in this study.