Abstracts

Rationale: Childhood convulsive status epilepticus (CSE) is associated with significant short-term morbidity but long-term outcomes remain unclear. Determining outcomes following CSE and predictors for a poor outcome is needed to aid prognostication and appropriate resource allocation. We carried out the first prospective pediatric population-based study on CSE, the north London convulsive status epilepticus in childhood surveillance study (NLSTEPSS). We are now investigating this unique cohort to determine their outcomes within 10 years after CSE, and in this abstract report preliminary data on neurological, cognitive and neuroimaging outcomes. Methods: In the current study, the status epilepticus outcomes study (STEPSOUT), enrolled children are invited to have a clinical neurological evaluation, cognitive assessment using the Wechsler Abbreviated Scale of Intelligence (WASI), and brain MRI on a 1.5T scanner. All MRIs were qualitatively assessed by an experienced pediatric neuroradiologist. Results: 90 children (41 male) have been investigated. Median follow-up was 8.1 years (range 6.4-9.6). 53 had complete (clinical, cognitive, and MRI) assessment. 22 had prolonged febrile seizures (PFS), 8 acute symptomatic (AS), 13 remote symptomatic (RS), 6 idiopathic, and 4 unclassified CSE. All children with PFS were neurologically normal, had full-scale IQ score >80, and none had epilepsy. The neuroimaging was normal in all, except findings suggestive of neurofibromatosis type 1 in one child (5%), and unilateral reduction in hippocampal volume without signal change in another (5%). Amongst those who had AS CSE, one developed epilepsy (12%) that remitted after 2 years; MRI was normal in 4 (50%), abnormal but with findings unlikely to be clinically significant in 3 (37%), and showed unilateral mesial temporal sclerosis (MTS) in 1 child (13%) who had CSE due to pneumococcal meningitis. All had IQ scores >80. All children with RS CSE, except two, had active epilepsy, significant cognitive (IQ <70) and/or motor impairments. The MRI findings were normal in 2, and suggestive of hypoxic ischemic injury in 2, compensated hydrocephalus in 3, perinatal middle cerebral artery infarction in 3, hypoglycaemic injury, unilateral MTS, and unilateral reduction in hippocampal volume without signal change in one each. Two (33%) children with idiopathic CSE had active epilepsy, and IQ scores of <70. The remaining had IQ scores >