SAN DIEGO – Prior neural impairment is the only independent predictor of long-term epilepsy and major cognitive and motor impairments following convulsive status epilepticus in children, researchers reported at the annual meeting of the American Epilepsy Society.
Investigators with the North London Status Epilepticus in Childhood Surveillance Study assessed 126 children a median of 8.5 years following convulsive status epilepticus (CSE) at a median age of 3.6 years.
Among children with prior neurologic impairment, the odds ratio for active epilepsy at follow-up was 7.1 (95% confidence interval, 1.8-27.7), for cognitive impairment, 16.3 (95% CI, 4.3-61.1), and for motor impairment, 9.8 (95% CI, 3.0-31.2).
Dr. Richard Chin
Outcomes were not predicted by the duration of the original attack or by whether it was focal or generalized or continuous or intermittent.
Overall, "if you have good neurologic development before status, your outcome is going to be very good," said senior investigator Dr. Richard Chin, director of the epilepsy center at the University of Edinburgh.
That’s often the case with pediatric febrile seizures, the most common cause of pediatric CSE. True to the point, none of the 30 children who entered the study following febrile seizures had active epilepsy or major motor impairments at follow-up; one child with a subsequent autism diagnosis had major cognitive impairment. MRIs were normal in 28 of the children; one child had evidence of neurofibromatosis and another had a unilateral hippocampal volume reduction without signal change.
Although prolonged febrile seizures have long been thought to be a significant risk factor for subsequent mesial temporal sclerosis (MTS), "we didn’t find evidence of that. None of our children with prolonged febrile seizures developed MTS. The relationship between febrile seizures and subsequent mesial temporal sclerosis is not as strong as once believed," Dr. Chin said.
The 51 children who entered the study with remote symptomatic CSE had previous diagnoses of cerebral palsy, hypoxic brain injury, and other problems; 48 (94%) had active epilepsy, 32 (63%) had major motor deficits, and 37 (73%) had major cognitive impairments at follow-up.
Seventeen children had suffered acute symptomatic CSE attacks; only one had active epilepsy and major cognitive impairment at follow-up. MRIs in a child whose attack was brought on by pneumococcal meningitis suggested left MTS.
Most of the rest of the children in the study were classified as having had an idiopathic or cryptogenic CSE attack – the majority had active epilepsy at follow-up and major motor or cognitive impairments.
Dr. Chin said that he had no disclosures.