Abstracts of Poster Presentations / Clinical Neurophysiology 125, Supplement 1 (2014) S1–S339 S171

variants on the EEG. Recently, some genes or genetic polymorphisms havebeen associated with brain development and eventually with epilepsiesassociated with structural brain lesions. Thus, it is plausible that some ofthese genes might also influence epileptogenicity in patients with epilepsy.Accordingly, genes coding Discoidin Domain Receptor Tyrosine Kinase 2(DDR2), Tescalcin (TESC), and High Mobility Group A Protein (HMGA2) wereassociated with brain volume, and might influence epileptogenicity.Objective: Investigate the association between DDR2, TESC and HMGA2genes and interictal spike activity in temporal lobe epilepsy (TLE).Methods: Case-control study of 76 patients with TLE exploring the in-fluence of polymorphisms rs10494373 of DDR2, rs7294919 of TESC andrs10784502 of HGMA2 on the incidence, distribution and lateralizationof interictal epileptiform EEG of these patients. All individuals had anawake and asleep standard EEG recordings, and tracings were analyzed byexperienced and certified electroencephalographers.Results: No association between rs10494373 of DDR2, and rs7294919 ofTESC polymorphisms with EEG spike rates was found in TLE, regardingthe EEG variables studied. However, presence of C allele in homozygosis inrs10784502 variant of HGMA2 was associated with significant less interictaldischarges (p=0.008), in other words, presence of T allele in this specificpolymorphism was associated with a doubling of discharges per minute,when compared with C allele in homozygosis (OR: 2.15±2.99 × 1.01±0.65).Conclusion: Our data allow us to hypothesize that variability in the HMGA2gene might influence EEG interictal epileptiform activity and epileptogenic-ity in patients with TLE. We believe that further studies will shed some lighton molecular mechanisms involved in the generation of EEG epileptiformactivity.

P459Electro-clinical features of focal epilepsy patients with postictalgeneralized EEG suppression

K. Jin1, H. Itabashi1, K. Kato1, Y. Kakisaka1, M. Iwasaki2, N. Nakasato1

1Tohoku University Graduate School of Medicine, Epileptology, Sendai, Japan;2Tohoku University Graduate School of Medicine, Neurosurgery, Sendai, Japan

Question: Postictal generalized EEG suppression (PGES) may be associ-ated with sudden unexpected death in patients with epilepsy. Generalizedtonic-clonic seizure (GTCS) is one of the well-known risk factors for PGES.However, which types of epilepsy are associated with PGES remain unclear.The present study investigated the electro-clinical features of focal epilepsypatients who suffered secondary GTCSs (sGTCSs) with PGES.Methods: We retrospectively reviewed 32 consecutive patients (13 men)with focal epilepsy aged 13 to 47 years, who presented with sGTCSsduring long-term video EEG monitoring. PGES was determined using thepreviously published criterion of generalized absence of EEG activity ofamplitude >10 μV. Patients with at least one sGTCS showing PGES wereclassified into the PGES (+) group (n=18, 56%). Electro-clinical findingsincluding localization of epileptic foci and lateralizing signs on semiologywere compared between the PGES (+) and (−) groups.Results: Temporal lobe epilepsy (TLE) was significantly (p<0.05) morecommon in the PGES (+) group (56%) than in the PGES (−) group (14%).Preceding “figure 4 sign” was significantly (p<0.001) less common in thePGES (+) group (33%) than in the PGES (−) group (93%). However, preceding“version” was not associated with PGES occurrence (56% in PGES (+) and36% in PGES (−) groups).Conclusions: Diagnosis of TLE and absence of “figure 4 sign” may be poten-tial risk factors for PGES. Localization of both epileptic foci and propagationpathways leading to sGTCSs are important for the occurrence of PGES.

P460Electroencephalography and clinical findings in a SCN8A epilepticencephalopathy: a case report

U. Vaher1, M. Nõukas2,3, A. Napa1, A. Metspalu2,3, T. Talvik1,4

1Children’s Clinic of Tartu University Hospital, Neurology andNeurorehabilitation, Tartu, Estonia; 2University of Tartu, Estonian GenomeCenter, Tartu, Estonia; 3University of Tartu, Institute of Molecular and CellBiology, Tartu, Estonia; 4University of Tartu, Dept. of Pediatrics, Tartu, Estonia

Background: Epileptic encephalopathies refer to a severe condition whereepileptic activity itself may contribute to progressive cognitive, behaviouraland motor dysfunction. Several genes have been associated with earlyinfantile epileptic encephalopathy (EIEE). We report a SCN8A mutation

contributing to neonatal epileptic encephalopathy. Previously, mutations inSCN8A have been reported in two patients with EIEE, the first case withepileptic encephalopathy presenting at 6 months of age, and second one at18 months of age.Methods and results: The patient was born at term in foetal hypoxia.Seizures were present immediately after birth; were generalized tonic withapnoea and bradycardia or focal tonic, very frequent and refractory to treat-ment. The patient also had central hypotonia, movement disorders (coarsetremor, myoclonias and voice expression), dysmorphic facial appearanceand multiple congenital anomalies. He did not achieve developmental mile-stones according to his age. Magnetic resonance imaging performed at theages of 9 days and 1.5 months was normal. At the age of 11 months mod-erate bilateral frontotemporal atrophy, thinning of the corpus callosum andmild delay in white matter myelination were described. Using whole-exomesequencing we identified a novel pathogenic c.3979A>G missense mutationin SCN8A. Electroencephalography (EEG) showed slight low-voltage back-ground activity and occasional interictal epileptiform discharges in bilateraltemporal areas during the first months. Ictal EEG was characterized by bilat-eral centrotemporal theta rhythm. Burst-suppression-like pattern in sleeprecording was noticed at 11 months of age. He died at the age of 1 year and5 months due to progressive respiratory failure during respiratory illness.Conclusion: Mutations in SCN8A can lead to EIEE with a broad spectrum ofEEG and clinical features. Detailed phenotypic descriptions are needed toavoid unnecessary investigations and optimize the therapy.

P461Vagus nerve stimulation is beneficial in a patient with posturalorthostatic tachycardia syndrome: a case report

A. Bujan Kovac1, S. Hajnsek1, Z. Petelin Gadze1, S. Nankovic1, G. Mrak2,V. Sulentic1, I. Kovacevic1, I. Adamec1, M. Habek1

1University Hospital Centre Zagreb, Dept. of Neurology, Zagreb, Croatia;2University Hospital Centre Zagreb, Dept. of Neurosurgery, Zagreb, Croatia

Question: Postural orthostatic tachycardia syndrome (POTS) is defined bya heart rate increment of 30 beats/min or more within 10 minutes ofstanding or head-up tilt (HUT) in the absence of orthostatic hypotension.Vagal nerve stimulation (VNS) is a safe and effective adjunctive treatmentfor drug-resistant epilepsy when surgery is inadvisable. Limited data sug-gest that long-term VNS therapy might affect cardiac autonomic function.However, there are no data of the VNS utility in patients with POTS.Methods: A 29-year-old female patient was implanted with VNS due topharmacoresistant epilepsy (elementary sensory-motor partial seizures ofthe left extremities and complex partial seizures of temporal origin withoccasional secondary generalization. Couple of years she noticed palpita-tions and dizziness in standing upright that were relieved by sitting orlying flat. Brain MRI showed bilateral frontoparietal polymicrogyria andright subependimal nodular heterotopia. During the preoperative work-upautonomic nervous system testing revealed POTS that was refractory to lifestyle modification measures.Results: One weak after implantation, VNS was initiated at 0.25 mA (dutycycle set to a 30-Hz signal frequency, a 500-ms pulse width, 30 sec ofon-time, and 3 min of off-time). HUT done at one month and three monthsafter implantation was normal. VNS was gradually increased to 1 mA whichled to significant reduction in seizure rate and disappearance of orthostaticintolerance symptoms.Conclusion: To our knowledge, this is the first reported case of the positiveVNS effect in patient with POTS. Further studies with a larger number ofpatients are needed.

P462Diffuse brain dysfunction in benign adult familial myoclonus epilepsy(BAFME)

T. Hitomi1, K. Kobayashi2, T. Kondo2, R. Matsumoto3, K. Terada4,M. Kanda5, R. Takahashi2, A. Ikeda3

1Kyoto University Graduate School of Medicine, Clinical Laboratory Medicine,Kyoto, Japan; 2Kyoto University Graduate School of medicine, Neurology,Kyoto, Japan; 3Kyoto University Graduate School of Medicine, Epilepsy,Movement Disorders and Physiology, Kyoto, Japan; 4National Epilepsy Center,Shizuoka Institute of Epilepsy and Neurological Disorders, Epilepsy, Shizouka,Japan; 5Takeda General Hospital, Neurology, Kyotio, Japan

Objectives: To clarify the clinical implication of posterior dominant rhythm