第33回日本脳科学会を開催して

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Clinical and experimental studies of epilepsy associated with focal cortical dysplasia

The definitive version is available at www.blackwell-synergy.comThe results of clinical and experimental studies on epilepsy associated with focal cortical dysplasia (FCD) are presented. We have been interested in the findings of abnormal increases in the numbers of small vessels in specimens of FCD resected from epilepsy patients. In the clinical study of 13 patients with epilepsy, specimens of FCD or dysembryoplastic neuroepithelial tumor (DNT) were examined using immunohistochemistry. The number of vessels in both lesions were greater than those in cortical specimens of autopsy cases without epilepsy. Because the vessels showed negative staining of VEGF, it was thought that the phenomenon of increase in the number of vessels was simply a hypervascularity, not a neovascularity. The local hypervascularity was expected to show local hyperperfusion in CBF-SPECT study, but interictal SPECT demonstrated local hypoperfusion and ictal SPECT showed hyperperfusion. This may have been caused by a functional change in those vessels. In the experimental study, we tried to make a new animal model of FCD to study epileptogenicity of FCD. When kainic acid had been infused into the neocortex in the neonatal rats, FCD was induced in adult Wistar rats. Histopathological examination revealed cortical dyslamination and abnormal neurons. On EEG, local spike bursts were elicited from the lesions, however, clinical seizures were not detected. Although the data are preliminary and observation over a longer period is required to determine whether spontaneous seizures will occur in this model, it is expected that this new model will be useful for studying epilepsy associated with FCD

第40回日本てんかん学会を開催して

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Antiepileptic effect of nefiracetam on kainic acid-induced limbic seizure in rats

ELSEVIER, Hashizume, K; Kunimoto, M; Maeda, T; Tanaka, T, S, EPILEPSY RESEARCH, 39(3), 221-228, 2000. authorNefiracetam is being studied as a novel cognition-enhancing agent; however, it has been suggested from studying its chemical structure that it has a potential anticonvulsive effect. We examined the antiepileptic effect of nefiracetam on kainic acid (KA)-induced seizures. KA was infused into the left basolateral amygdaloid nucleus, and focal limbic seizures were induced in 43 male Wistar rats. During status epilepticus, 10, 50, 100 or 200 mg/kg of nefiracetam was intravenously injected. Nefiracetam inhibited KA-induced limbic seizures at doses over 100 mg/kg while it had a sedative effect on the animals. In [14C] deoxyglucose autoradiographic studies, the propagation of seizure-induced hypermetabolic areas was also suppressed dose-dependently. From the results, it was indicated that nefiracetam has an antiepileptic effect and that its application may suppress seizure propagation. Further study is required whether this agent is available as a novel anticonvulsant

Correlation of EEG, neuroimaging and histopathology in an epilepsy patient with diffuse cortical dysplasia

This is the author-created version of SPRINGER VERLAG, Hashizume, K; Kiriyama, K; Kunimoto, M; Maeda, T; Tanaka, T; Miyamoto, A; Miyokawa, N; Fukuhara, M, CHILD'S NERVOUS SYSTEM, 16(2), 2000, 75-79. The original publication is available at www.springerlink.com. authorThe correlation between scalp EEG, intraoperative electrocorticogram, neuroimaging and histopathology was examined in a epilepsy child with diffuse cortical dysplasia. A 6-year-old girl with moderate mental retardation had suffered from intractable complex partial and generalized epilepsy since 2-year-old. MR images demonstrated unilateral large macrogyria/polymicrogyria and schizencephaly in the right occipital lobe. The epileptic focus was detected on the macrogyria by EEG and single-photon emission tomography. However, intraoperative electrocorticogram showed frequent spikes from the polymicrogyria and no paroxysmal activity in the macrogyria. The polymicrogyria was resected including the macrogyria using an image-guided system. The histological findings revealed that the macrogyria was covered and separated with glial bundles. It has been reported that epileptogenisity was produced from abnormal neurons and their arrangement in cortical dysplasia, however in this case, the major dysplastic lesion had no epileptogenisity, rather the focus might be in polymicrogyria around the lesion

【3D画像医学の進歩 画像診断に基づく治療戦略】 3D画像医学の臨床 脳外科領域の診断と治療 てんかんの診断と外科治療における3D画像

著者版Development of functional neuroimaging is contributed to diagnosis and treatment in epilepsy patients. The dipole analysis of interictal spikes on EEG or MEG provides 3D-localization of the irritable zone. Interictal and ictal CBF-SPECT reveals the local change in CBF associated to epileptic focus. Three-dimensional stereotactic surface projection (3D-SSP) of SPECT is useful to recognize the seizure generation area. Furthermore, Subtraction ictal SPECT coregistration of MRI (SISCOM), that is fusion image of anatomical and functional brain images, is beneficial to understand the localization of seizure-induced hyperperfusion area. During epilepsy surgery, image-guided system makes less-invasive and accurate surgery possible. Functional image-guided surgery for epilepsy will be available in near future

ラット焦点性てんかん発作に及ぼす低体温の影響

雑誌掲載版低体温療法は,外傷,脳虚血と同時に難治性てんかん重積状態の治療に応用できる可能性があると示唆され