Role of neuroimaging and electroencephalogram in first unprovoked seizures in children from Cairo

Background
First unprovoked seizure (FUS) and complex febrile seizure (CFS) are common pediatric issues of great debate with respect to the role of electroencephalogram (EEG) and neuroimaging in their diagnosis.
Aim
To determine the frequency of abnormal EEG and neuroimaging results in children with FUS and CFS and to detect the correlation between EEG and neuroimaging results.
Patients and methods
A total of 100 children (6 months to 12 years of age), who presented with first afebrile or CFS underwent EEG and neuroimaging (computed tomography and/or MRI). This was a prospective randomized controlled trial.
Results
A total of 100 cases within the age group 6 months to 12 years were recruited. FUS was seen in 63 cases and CFS in 37 cases. Overall, 69.8% cases of FUS were generalized and 30.2% were focal. The prevalence of EEG abnormality was found in 33% of the whole studied population: 44.4% in patients with FUS and 13.5% in patients with CFS. The prevalence of neuroimaging abnormality was found in 15% of the whole studied population: 20.6% in patients with FUS and 5.4% in patients with CFS. Neuroimaging abnormality was seen more commonly in those patients who had an abnormal EEG, with a statistically significant increase in cases with FUS.
Conclusion
EEG and neuroimaging abnormalities were more prevalent in children with FUSs than those with CFSs. Abnormal EEG and neuroimaging were more common in children with partial seizures than those with generalized seizures. Neuroimaging was abnormal in a significant number of children having abnormal EEG, so neurologically free patients having normal EEG can be safely discharged without neuroimaging, if follow-up is assured. When EEG is abnormal in FUS, the probability of having abnormal neuroimaging increases as compared with those cases where EEG is normal. In case of generalized seizures, patients with abnormal EEG may have abnormal computed tomography/MRI scans, but there are fewer possibilities of a patient with abnormal EEG to have a normal neuroimaging. In partial seizures, abnormal EEG increases the risk of having abnormal neuroimaging than in generalized seizures, and normal EEG in partial seizures markedly decreases the risk of having an abnormal neuroimaging generalized seizures. CFSs in otherwise neurologically free children rarely indicate the presence of lesion on neuroimaging even if associated with EEG abnormalities. Neuroimaging abnormalities in neurologically free children with FUS and CFSs do not require urgent intervention.