Role of early EEG and neuroimaging in determination of prognosis in children with complex febrile seizure

Abstract

Background: The present study investigates the role of early use of EEG in children with no known neuropathology prior to the first CFS, and the contribution made by computed tomography (CT) and magnetic resonance imaging (MRI) to treatment and prognosis.

Methods: Over a period of 7 years, the authors evaluated 159 children (age range: 2 months-5 years) who were being treated for CFS at Haydarpasa Numune Training and Research Hospital, Pediatrics Clinic, Istanbul, Turkey, and who had no previously known neurological disorder. Patients who presented with febrile seizure were determined to have CFS if they fulfilled the following criteria: <3 months of age when seizure occurred, duration of seizure >/=15 min, more than one seizure occurred during a single episode of illness, or focal seizures and postictal neurological deficit was found. EEG was performed on all patients. CT was performed on the patients who had postictal neurologic deficit or focal seizures. Cranial MRI was performed on patients who had focal findings in their EEGs.

Results: Electroencephalogram abnormality was found in 71 cases; 51 of these were diagnosed with epilepsy during follow up. Six of the 16 cases whose EEGs were abnormal between days 2 and 6 were diagnosed with epilepsy. Twenty of the 30 cases whose EEGs were abnormal between days 7 and 10 were diagnosed with epilepsy. All 25 cases who had abnormal EEGs after day 11 were diagnosed with epilepsy. CT was performed for 36 patients, of which five were found to have pathological changes. Pathological changes were detected in two of the nine patients who had cranial MRI. Patients who received CT or MRI were all diagnosed with epilepsy during follow up.

Conclusion: The results suggest that if neurological examination of CFS patients are normal after their clinical status has stabilised, EEG should be performed after 7 days at the earliest, however for the most accurate diagnosis EEG should be performed 10 days after CFS. The most important predictor for neuroimaging was found to be detection of postictal neurologic deficit. MRI had no advantages over CT in first treating CFS in the emergency unit.