P97: Frontal lobe epilepsy versus NREM sleep parasomnia: clinical and EEG characteristics

s of Poster Presentations / Clinical Neurophysiology 125, Supplement 1 (2014) S1–S339 S75 ization as focal or generalized, as presentation was mixed. The convulsions seldom qualified as simple generalized tonic-clonic. Nearly half of our patients had generalized convulsive seizures followed by postictal EEG suppression, a possible biomarker for sudden unexpected death in epilepsy. P97 Frontal lobe epilepsy versus NREM sleep parasomnia: clinical and EEG characteristics P. Meritam1,2, M. Lauritzen1,3, B. Wanscher1, P. Jennum1,4, K. Benedek1 1Glostrup Hospital, Clinical Neurophysiology, Glostrup, Copenhagen, Denmark; 2Danish Epilepsy Center, Clinical Neurophysiology, Dianalund, Denmark; 3Copenhagen University, Neuroscience and Pharmacology, Copenhagen, Denmark; 4Copenhagen University, Copenhagen, Denmark Background: Nocturnal paroxysmal events may be characterized clinically, and by video EEG and video polysomnographic recordings, but even when applied rigorously it is often difficult to distinguish between frontal lobe epilepsy (FLE) and NREM parasomnia (NREM-P). Aim of study: To assess the value of high frequency EEG synchronization during pre-ictal state in order to differentiate between FLE and NREM-P. Methods: We analyzed the clinical features as well as macroscopic EEG and polysomnografic recordings of 12 patients with frontal lobe epilepsy and 12 patients with NREM parasomnia. Short time Fast Fourrier Transformation (FFT), spectral data analysis as well as spectral coherences were evaluated among all electrodes at 1-10 seconds prior to the nocturnal episode in both patient groups. Results: Evaluation of clinical features of frontal lobe seizures and NREM parasomnia events showed significant differences between the two groups. FLE seizures had shorter duration (<2 min), higher frequency per night (mean 9.75±3.9) as well as per month (mean 22.75±8) as compared to NREM-P events (mean 4.33±3.9 and 15.6±12.6 respectively). The semiology of FLE seizures were more stereotyped (p<0.0001) than NREM-P attacks with higher incidence of dystonic or tonic posturing and abrupt offset with recollection (p=0.011) of the event. In comparison, the semiology of NREMP events was heterogenous, with a more gradual offset and with the patient often going back to sleep and having only a vague or no recollection of the event. Our results were consistent with a higher positive FLEP scale in FLE (mean 5.42±2.3) as compared to NREM-P (mean −2.65±3.6). No abnormal rhythmic activity was observed in the macroscopic EEG recordings of most patients (FLE 58% n=7, NREM-P 92% n=11). In contrast, FFT analysis of the EEG signal showed remarkable increases of phase coherence in the high frequency beta and gamma range, mainly occurring around the frontal areas in patients with FLE prior to seizures. This was not observed in patients with NREM sleep parasomnia patients. Conclusion: The clinical features of FLE and NREM sleep parasomnia differ importantly. In addition EEG signal analysis with focus on the highfrequence EEG bands is a useful tool in distinguishing between nocturnal events. Glossary: FLE, frontal lobe epilepsy; REM, rapid eye movement; NREM, non-REM; EEG, electroencephalopraphy; FLEP scale, frontal lobe epilepsy and parasomnia scale. P98 Methionine-enriched diet increases susceptibility of rats to epilepsy: the role of sodium-potassium pump D. Hrncic1, A. Rasic-Markovic1, M. Colovic2, D. Krstic3, R. Obrenovic4, Z. Grubac1, V. Susic5, D. Macut4, D. Djuric1, O. Stanojlovic1 1Belgrade University Faculty of Medicine, Institute of Medical Physiology “Richard Burian”, Lab of Neurophysiology, Belgrade, Serbia; 2Institute for Nuclear Sciences “Vinca”, Belgrade, Serbia; 3Belgrade University Faculty of Medicine, Department of Medical Chemistry, Belgrade, Serbia; 4Clinical Center of Serbia, Belgrade, Serbia; 5Serbian Academy of Sciences and Arts, Belgrade,