1998 Fiscal Year Final Research Report Summary
Localization of generator sources of ictal epileptiform activities by dipole tracing method.
| Project/Area Number |
08671565
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Cerebral neurosurgery
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| Research Institution | China University |
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Principal Investigator |
MINE Seiichiro Chiba University, School of Medicine, Assistant, 医学部, 助手 (70190709)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAJIMA Yoshi Chiba University, School of Medicine, Professor, 医学部, 教授 (60092079)
YAMAURA Akira Chiba University, School of Medicine, Professor, 医学部, 教授 (40009717)
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| Project Period (FY) |
1996 – 1998
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| Keywords | Epilepsy / Dipole Tracing / Epilepsy Surgery / Epileptogenic focus |
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| Research Abstract |
1. Generator sources of ictal epileptiform activities (lEAs) recorded by scalp electrodes were estimated by dipole tracing method. The locations of the generator sources of IEAs were compared with the results of the chronic subdural EEG recording and neuro-imagings ; magnetic resonance imaging (MRI), positron emission tomography (PET) and single photon emission computed tomography (SPECT). 2. Nine cases with intractable epilepsy ; 3 frontal lobe epilepsy (FLE) and 6 temporal lobe epilepsy (TLE), were studied. 3. In 2 cases with FLE and 4 cases with TLE (group 1), generator sources of IEAs were localized within the restricted area which was considered as epileptogenic foci. 4. In one cases with FLE and 2 cases with TLE (group 2), generator sources of IEAs were scattered around the brain, then the epileptogenic foci could not be identified. Electrical artifacts such as electromyogram or direct current potential were the causes of the scattering of dipoles. 5. In group 2, (1)Organic lesions were found by MRI in 4 cases, and the generator sources of IEAs were localized around the lesions. (2)Localized glucose hypometabolism was found by PET in 3 cases, and localized hypoperfusion of cerebral blood flow was found by SPECT in 3 cases. Locations of generator sources of IEAs were around the locations of hypometabolism or hypoferfusion. (3)In 3 cases locations of the generator sources of IEAs detected by chronic subdural electrodes were consistent with the locations of the generator sources estimated by dipole tracing method. 8. In 4 cases of TLE DT method discriminated between medial temporal epileptogenic focus and lateral temporal epileptogenic focus. This was impossible by visual interpretation of scalp EEG.9. Noninvasive localization of epileptogenic focus was accomplished by DT method applied to IEAs recorded by scalp electrodes. DT method will replace the invasive intracranial EEG recording in selected cases.
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