Epoxide hydrolase (EH) and glutathione S-transferase (GST) are involved in the detoxification of epoxide, which may be attributable to the mechanism of ter-atogenicity of antiepileptic drugs (AEDs).In this study, such AEDs as phenytoin (PHT), phenobarbital (PB), carbamazepine (CBZ), zonisamide (ZNS) and valproic acid (VPA) on the activities of these enzymes were investigated using rat liver microsomes.Within respective therapeutic concentrations, PHT, PB, CBZ and ZNS did not affect EH activity while VPA showed a concentration-dependent inhibitory effect on EH activity at 100μg/mlor more.Regarding the activities of GST isozymes, PHT and ZNS did not affect the activities at any concentrations studied while CBZ (10μg/ml or more) and PB (40μg/ml or more) inhibited GST 7-7 activity.VPA showed concentration-dependent inhibitory effects on activities of GST 1-1, 2-2, 4-4 ad 7-7 at 100μg/ml or more.These results may partly explain the increased incidences of malformation in offspring exposed to AED polytherapy including VPA, CBZ and PB through the accumulation of epoxide intermediates of AEDs.

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he dipole tracing method using three-layered head model was applied for estimating the electric current sources of photoparoxysmal responses in two children with idiopathic localization-related epilepsies and without visually induced clinical seizures.We investigated each photoparoxysmal response divided into two or three parts, preceding spike part, diffuse wave, and diffuse spike part.The dipole of preceding spikes in photoparoxysmal responses was anatomically estimated in the area related to each clinical feature of complex partial seizures.But the dipoles of diffuse spikes in photoparoxysmal responses were not detected stably.

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Ten long-term outpatients having temporal lobe epilepsy and unilateral epileptic focus in scalp EEG were studied in interictal periods using1H magnetic resonance spectroscopy (MRS). The N-acetylaspartate (NAA)/creatine plus phosphocreatine (Cr) ratio in the mesial temporal region ipsilateral to the epileptic focus was signifi-cantly decreased in patients, compared to that of control subjects, which reflected neuronal loss or neuronal dysfunction. NAA/Cr ratios were also decreased in the temporal region contralateral to the epileptic focus in 6 out of 10 patients, although less than those in the ipsilateral region. The group with decreased levels of NAA in only the right epileptic focus showed less severity of symptoms related with temporal lobe epilepsy, such as complicated seizure pattern, efficacy of antiepileptic drugs, psycho-logical disturbances, social adaptation and prognosis, than groups with a bilateral decreases in NAA levels. These symptoms were particularly worse in the group with left EEG focus and NAA levels that were decreased not only in the left mesial temporal region ipsilateral to the epileptic focus but also in the contralateral temporal region. H MRS study demonstrated that laterality and bilateral decrease in NAA/Cr ratios have a close relation with clinical symptoms, course and prognosis in temporal lobe epilepsy.

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The Perirhinal Cortex and the Seizure Generalization of Kindling in the Cat Akihisa Orita It has recently been demonstrated that the perirhinal cortex (PRC) is an impor-tant site for the generalization of kindled seizures.In this study, we observed charac-teristics of afterdischarges (ADs) in the PRC during amygdala kindling as well as the characteristics of the primary PRC kindling. PRC produced apparent ADs during the early stage of amygdala kindling. ADs were most predominant in PRC in the contralateral hemisphere when the animals showed stage 3 motor seizures.Analysis of interictal discharges (IIDs) revealed that there are four patterns in the distribution of IIDs. Only PRC always showed IIDs in every IID pattern. The development of motor seizures and ADs in the primary PRC kindling demonstrated that PRC kindling-induced epileptic activity was propagated first to the hippocampus, followed by the neocortex and then the amygdala before the full-down seizures. PRC kindled seizures were stably reproducible after the completion of kindling. These results suggest that PRC appears to be important for the seizure generalization of amygdala kindling. The development of PRC kindling is similar to that of neocortical kindling, although the stability of fully-developed seizures indicated that it is more similar to seizures from the limbic sites, suggesting that PRC kindling has characteristics from both neocor-tical and limbic kindling.

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A 17-year-old girl had experienced only one episode of non-convulsive status epilepticus (NCSE) at age 7 months. NCSE appeared 2 days after cyproheptadine hydrochloride administration for upper respiratory infection. EEG (and movement) during NCSE showed a cyclic pattern; (1) diffuse 2Hz high voltage slow waves with spike rhythm (akinetic status)→(2) suppressive phase (presence of involuntary or voluntary movements)→(3)<6Hz waves arising from P₃-O₁ spread to the whole surface (decrease of motion)→(1). She recovered immediately after diazepam adminis-tration.Clinical and EEG findings during this episode were similar to those of complex partial seizure (CPS);thus the cause of NCSE was considered complex partial status epilepticus.She had no further episode of seizure or abnormal EEG until age17. The favorable outcome suggests that the episode of NCSE was due to benign infantile partial epilepsy which includes benign CPS in infancy or a side effect of cyprohe-ptadine hydrochloride.

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A Case of Hemimegalencephaly with Characteristic Evolvement of EEG Ritsuko Shigetomo, Hiroyuki Shimizu, Taketoshi Maehara, Nobuyoshi Kaito, Akira Yagishita, Masaya Oda, Nobutaka Arai, Kazuhiko Komiya, Hiroshi Tanaka, Fumio Hayakawa We report a case of hemimegalencephaly whose serial EEGs disclosed very interesting features.The patient's seizures started immediately after birth. Scalp EEG first showed epileptic discharges in the right affected brain. However, over the time course of three years with intransigent seizures, interictal epileptic discharges gradu-ally shifted from the right hemisphere to the contralateral“healthy”brain. At the age of 3 years and 4 months, she underwent a right functional hemispherectomy. After the operation, her seizures completely ceased, with the exception of slight myoclonic jerks in the morning.We speculate that a mirror focus may have been formed in the opposite hemisphere by incessant electric stimulation from the affected hemisphere. This case undescores the importance of a comprehensive diagnosis which encompasses scalp EEG, semiology, and image diagnosis for the selection criteria of epilepsy surgery.

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