Optimizing electroencephalographic studies for epilepsy diagnosis in children with new-onset seizures.
OBJECTIVE
To establish whether early electroencephalography (EEG) or later sleep-deprived EEG (SD-EEG) has a higher yield of epileptiform and background abnormalities in children with new-onset seizures, and to use EEG results to assist in diagnosis of electroclinical epilepsy syndromes at presentation.


METHODS
Prospective analysis blinded to EEG protocol and epilepsy diagnosis.


METHODS
Regional service capturing a pediatric population of 121,000.


METHODS
Consecutive untreated children aged 2 to 16 years presenting to emergency departments with new-onset seizures (excluding myoclonic and absence seizures).


METHODS
Each child had 2 EEG protocols: an early EEG study (within 24 hours following a seizure) and an SD-EEG study (48 hours to 4 weeks following a seizure). Epilepsy diagnosis was made independently by 2 pediatric epileptologists.


METHODS
Rate of epileptiform abnormalities and slowing in the 2 EEG studies. The secondary outcome measure was diagnosis of epilepsy syndrome where possible.


RESULTS
Of 92 children studied, 50 (54%) had a single seizure; 42 (46%) had 2 or more seizures at presentation. Seizures were focal in 61 children (66%) and generalized in 19 (21%). Epileptiform discharges occurred in 56 SD-EEGs (61%) and 52 early EEGs (57%) (P = .27). Background slowing occurred in 26 SD-EEGs (28%) and 42 early EEGs (46%) (P < .001). Parents preferred early EEG (65 parents [71%]) to later SD-EEG (14 parents [15%]) because of availability of earlier results and epilepsy diagnosis. Forty-two of 92 children (46%) were diagnosed with a specific electroclinical syndrome.


CONCLUSIONS
Early EEG and SD-EEG studies have a similar yield of epileptiform abnormalities. Background abnormalities are more frequent in early EEGs. The EEG results at presentation in new-onset seizures support epilepsy diagnosis, with electroclinical syndromes diagnosed in almost 50% of children.
Sadleir
Lynette G
LG
Department of Pediatrics, Wellington School of Medicine and Health Sciences, University of Otago, PO Box 7343, Wellington South, 6242, New Zealand. lynette.sadleir@otago.ac.nz
Scheffer
Ingrid E
IE
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D004569:Electroencephalography / Q000379:methods*; D004827:Epilepsy / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012640:Seizures / Q000175:diagnosis*; D012890:Sleep