P.073 Diagnostic utility of specific abnormal EEG patterns in children

Abstract

Background: CTS and PPR are common EEG findings that are classically associated with CECTS and GGE respectively. PPD and sleep spindles are physiologic phenomenon that occur in respond to intermittent photic stimulation and sleep respectively. Methods: We reviewed EEG studies with CTS, PPR, asymmetric PPD, or asymmetric sleep spindles. For CTS, we determined sensitivity, specificity, PPV and NPV for a diagnosis of CECTS. For PPR, we determined the same diagnostic outcome measures for a diagnosis of GGE or JME. For each of asymmetric PPD and asymmetric sleep spindles, we determined the same diagnostic outcome measures for the presence of a structural abnormality on brain MRI. Results: CTS had 83% specificity and 75% PPV in children with normal neurological examination. PPR had high specificity of 92% and NPV 92% for GGE; for JME, PPR also had high sensitivity (92%). Asymmetric PPD had low sensitivity for structural brain abnormalities (17%), with specificity 80%. In contrast, asymmetric sleep spindles had higher sensitivity and specificity, 44% and 97%, respectively. Conclusions: CTS are seen with CECTS and other conditions. PPR is highly indicative of a GGE, though may be seen other conditions. Relative attenuation of sleep spindles is a more reliable indicator of structural brain malformation than asymmetric PPD.