Abstracts

Rationale: QEEG analysis in PGE has focused primarily on spike and wave frequency, spike counts and burst duration. After-going slow waves occur when neurons do not fire, representing a period of diffuse cortical inhibition. The effects of antiepileptic medications (AEDs) on these slow waves have not been well characterized. Methods: The EEGs of 5 patients with non-absence, untreated PGE were compared to those of 5 patients, on AEDs, seizure free for a minimum of one year. A commercially available QEEG analysis tool was used to analyze spike and wave bursts from each patient, recorded while awake. After- going slow wave durations in a run of SWDs were measured and averaged. The first and subsequent slow wave durations were calculated as a percentage of the duration of the terminating wave in a burst. Results: In a spike and wave run each successive wave progressively increased in duration in both the untreated and treated groups. While the terminating slow wave durations did not differ between groups, the first after-going slow wave in the treated group was significantly longer (p< .05 unpaired two tailed T-test). Additionally, slow waves in isolated spike and wave discharges did not differ between groups Conclusions: First after going slow wave durations are significantly longer in AED controlled PGE patients compared with those from drug naive patients. Further studies are needed to determine whether this quantitative EEG finding predicts seizure control and whether it differs among AEDs.