2002 Fiscal Year Final Research Report Summary
Pathomechanisms of dystonia: Elucidation of abnormal inhibitory
| Project/Area Number |
13470134
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Neurology
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
SHIBASAKI Hiroshi Kyoto University, Graduate School of Medicine, Professor, 医学研究科, 教授 (30037444)
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| Co-Investigator(Kenkyū-buntansha) |
MIMA Tatsuya Kyoto University, Graduate School of Medicine, Assistant Professor, 医学研究科, 助手 (20324618)
MEZAKI Takahiro Kyoto University, Graduate School of Medicine, Assistant Professor, 医学研究科, 助手 (40335287)
IKEDA Akio Kyoto University, Graduate School of Medicine, Lecturer, 医学研究科, 講師 (90212761)
NAGAMINE Takashi Kyoto University, Graduate School of Medicine, Associate Professor, 医学研究科, 助教授 (10231490)
FUKUYAMA Hidenao Kyoto University, Graduate School of Medicine, Professor, 医学研究科, 教授 (90181297)
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| Project Period (FY) |
2001 – 2002
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| Keywords | Focal dystonia / Motor inhibition / Sensorimotor Cortex / Premotor cortex / Event-related functional MRI / Transcranial magnetic stimulation / Subdural recording / Sensorimotor integration |
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| Research Abstract |
In order to elucidate the mechanisms underlying the development of focal dystonia, we investigated the patients with focal hand dystonia, mainly those with writer's cramp, by using non-invasive techniques of different principles. By applying the new technique of event-related functional MRI, we showed that the cortical areas in the primary sensorimotor cortex (S1-M1) and the supplementary motor area (SMA) activated by voluntary muscle relaxation as well as contraction were diminished in patients with writer's cramp compared with normal controls, indicating the functional abnormalities in those cortical areas, By using the transcranial magnetic stimulation (TMS) in patients with writer's cramp, we showed that low frequency repetitive TMS over the premotor area improved the clinical symptoms and prolonged the silent period whereas the same stimulation over the S1-M1 or the SMA did not. In relation to this, by using a choice reaction time paradigm with paired visual stimuli, recording of event-related potentials from subdural electrodes in patients with intractable epilepsy as a part of pre-surgical evaluation disclosed an important role of the premotor cortex in sensorimotor integration. Thus, the inhibitory mechanism of S1-M1 is abnormal in focal hand dystonia and abnormal function of the premotor cortex seems to be involved in its pathomechanisms.
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