Magnetic resonance imaging (MRI) and electroencephalographic (EEG) findings in a cohort of normal children with newly diagnosed seizures.

In the initial assessment of children with new-onset seizures, the suggestion that electroencephalography (EEG) should be standard and that magnetic resonance imaging (MRI) should be optional has been questioned. The purposes of this study were to (1) describe the frequency of EEG and MRI abnormalities and (2) explore relationships between MRI and EEG findings to determine their relevance in the assessment of children with new-onset seizures who are otherwise developing normally. As part of an ongoing, prospective study of children with new-onset seizures, we studied 181 children (90 girls and 91 boys). Children were entered into the study within 3 months of their first-recognized seizure. The association between EEG and MRI abnormalities was explored using a chi-square test. Abnormal MRI findings were found in 32.6% (n = 59) of the sample. The EEG and MRI results agreed with respect to classification into normal or abnormal in 37% (n = 67). Of the 50 children with a normal EEG, however, 21 (42%) were found to have an abnormal MRI. We found an unexpectedly high frequency of imaging abnormalities in our sample of otherwise normal children, although the significance of these findings is not clear. Follow-up of these patients will help us interpret the importance of the abnormalities. Despite our relatively small sample, however, our findings indicate that a normal EEG does not reliably predict a normal MRI in children with first seizures.