WASHINGTON – Electrographic seizures persisted following control of convulsive status epilepticus in about a third of children treated in pediatric intensive care units at 11 hospitals, according to a retrospective study.
Of 98 children aged 1 month to 21 years (median, 5 years) who underwent continuous electroencephalographic monitoring (typically for 12-48 hours) after presenting with convulsive status epilepticus (CSE), 32 (33%) had electrographic seizures following control of CSE, including 11 (34%) who had electroencephalographic-only seizures, and 17 (53%) who had electroclinical seizures. In four patients (13%), data regarding clinical correlates were unavailable, Dr. Iván Sánchez Fernández reported at the annual meeting of the American Epilepsy Society.
Factors significantly associated with persistent electrographic seizures were prior diagnosis of epilepsy (P = .029) and the presence of interictal epileptiform discharges (P less than .0005), but about a third of children with persistent electrographic seizures had no clinical correlates associated with the seizure, said Dr. Sánchez Fernández of the department of neurology at Boston Children’s Hospital and Harvard Medical School, Boston.
Few data looking at the rate of electrographic seizures after CSE are available. The current findings are among the first to look at this and to characterize persistent electrographic seizures after CSE, he said.
Of the 32 patients who had electrographic seizures, 15 (47%) had electrographic status epilepticus, including 6 patients (40%) with continuous status epilepticus and 9 (60%) with intermittent status epilepticus. A comparison of patients with electrographic seizures who had status epilepticus and patients with electrographic seizures who did not have status epilepticus, as well as with those who had no electrographic seizures, showed that the presence of an abnormal initial background category on continuous electroencephalogram and the presence of sporadic interictal epileptiform discharges were significantly associated with electrographic status epilepticus, he said.
Slightly more than half (53) of the children included in this study were boys. The typical duration of electrographic seizures was less than 1 minute in 34% of cases, 1-5 minutes in 31% of cases, 6-30 minutes in 22% of cases, and more than 30 minutes in 13% of cases. Seizure onset localization was focal in 41% of cases, multifocal in 20.5% of cases, generalized in 30.8% of cases, and unknown in 7.7% of cases. Maximal spread localization was focal-unilateral in 38% of cases, bilateral in 50% of cases, and unknown in 12% of cases.
Patients with electrographic seizures also stayed in the ICU longer than did those without such seizures. The median ICU stay was 9.5 days for those with electrographic seizures, compared with only 2 days for those without electrographic seizures, but it is unclear from these data whether the seizures were the cause of the prolonged stay, Dr. Sánchez Fernández said.
No disclosures were available at press time.