PS-59-4 Clinical characteristics of epilepsy patients with multiple ictal foci

Abstract

Electroencephalography (EEG) is an important tool in investigating children with neurological disorders, particularly epilepsy. The objectives were to examine the relationship between clinical indications and EEG results, and assess the predictability of a normal result. 438 consecutive paediatric EEGs were included prospectively. One certified electroencephalographer (EEGer) reviewed EEG requisitions and recorded his prediction of a normal result. EEGs were reviewed separately and the relationship between the clinical indications and EEG abnormalities was recorded. The children’s mean age was 5 years (SD 4.2). Paediatric neurologists ordered 32% of EEGs. The first EEG was studied in 65% of cases. Overall, 55% of the EEGs were abnormal. Repeat EEGs were twice as likely to be abnormal (95% CI 1.3–3, P= 0.001). Established epilepsy, using antiepileptic drugs, and sleep record, highly correlated with an abnormal result ( P< 0.0001). The EEGer predicted 26% of the EEGs to be normal. A normal EEG was correctly predicted in 97% of non-epileptic paroxysmal events, however, normalization of EEG was correctly predicted in only 54% of children with seizures. EEGs of 15 (3.4%) children with epilepsy revealed unexpected findings that completely changed their management. To conclude, a normal EEG is highly predictable in non-epileptic paroxysmal events. EEGs of children with epilepsy are not predictable and may yield unexpected results.