Prospective study of new-onset seizures presenting as status epilepticus in childhood

Abstract

Objective: To characterize children with new-onset seizures presenting as status epilepticus at a tertiary care children's hospital.

Methods: Prospectively collected data were reviewed from a database derived from a mandated critical care pathway. A total of 1,382 patients presented with new-onset seizures between 2001 and 2007.

Results: A total of 144 patients presented in status epilepticus. The average age was 3.4 years. The majority of seizures (72%) lasted between 21 and 60 minutes. The majority of patients had no significant past medical history; one-fourth had a family history of epilepsy. Five (4%) patients with EEGs had electrographic seizures during the study, captured only with prolonged monitoring. The most common etiology was febrile convulsion, followed by cryptogenic. The most common acute symptomatic cause was CNS infection; the most common remote symptomatic cause was cerebral dysgenesis. Combined CT and MRI provided a diagnosis in 30%. CT was helpful in identifying acute vascular lesions and acute edema, whereas MRI was superior in identifying subtle abnormalities and remote symptomatic etiologies such as dysplasia and mesial temporal sclerosis.

Conclusions: Children who present in status epilepticus that is not a prolonged febrile convulsion should undergo neuroimaging in the initial evaluation. For any child who presents in status epilepticus and has not yet returned to baseline, the possibility of nonconvulsive status epilepticus should be considered. Although CT is often more widely accepted, especially in the urgent setting, strong consideration for MRI should be given when available, due to the superior yield.

Figure 1 Age distribution of new-onset status epilepticus The distribution of age is positively skewed. Those with true febrile status epilepticus (≥38.0 °C) are shaded in gray, with the greatest distribution less than 2 years of age. Patients who presented in status epilepticus with a fever, but not febrile status epilepticus, spanned all ages.

Figure 2 Summary of diagnostic imaging findings, HCT compared to MRI ▪ = number of patients with febrile status epilepticus (≥38.0°C) and normal neuroimaging. HCT = head CT; MTS = mesial temporal sclerosis.