Nonconvulsive status epilepticus in a pediatric intensive care unit

We aimed to describe nonconvulsive status epilepticus in terms of patient age, etiology, initial presentation, and electroencephalogram and neuroimaging findings. Twenty children with nonconvulsive status epilepticus were identified by a retrospective review of children who underwent long-term electroencephalogram monitoring in a pediatric intensive care unit. Age ranged from 2 months to 18 years, and in 30% of patients, the age was <1 year. Nonconvulsive status epilepticus occurred most commonly in children with prior epilepsy (35%) or congenital heart disease (25%). Prior to nonconvulsive status epilepticus, most had experienced isolated seizures (55%) or convulsive status epilepticus (20%), but some had only preceding mental-status change (25%). The most common etiologies were exacerbation of epilepsy (35%) and ischemic stroke (25%). No children aged <1 year had preexisting epilepsy. Electroencephalograms confirmed nonconvulsive status epilepticus immediately in 65%. Nonconvulsive status epilepticus lasted up to 8 days, and neuroimaging was abnormal in 82% of patients. Nonconvulsive status epilepticus occurs in a heterogeneous group of children, results from acute symptomatic etiologies in children aged <1 year, most frequently follows isolated convulsions but can occur with only preceding mental status change, and is often prolonged. These findings suggest that a high level of suspicion for nonconvulsive status epilepticus must be maintained, and long-term electroencephalogram monitoring may be indicated in a large number of patients.