| Project/Area Number |
12671513
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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 |
Anesthesiology/Resuscitation studies
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| Research Institution | KURUME UNIVERSITY |
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Principal Investigator |
SUGIYAMA Kazuhide Kurume University, Anesthesiogy, Assistant Professor, 医学部, 講師 (80140721)
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| Co-Investigator(Kenkyū-buntansha) |
SATO Teruyuki Kurume University, Anesthesiology, Instructor, 医学部, 助手 (20320236)
MIYAGAWA Yoshikado Kurume University, Anesthesiology, Instructor, 医学部, 助手 (20312150)
HARADA Hideki Kurume University, Anesthesiology, Assistant Professor, 医学部, 講師 (30198923)
MATSUDA Tsuruo Kurume Institute of Technology, Technology, Associate Professor, 工学部, 助教授 (60258598)
伊藤 貴彦 久留米大学, 医学部, 助手 (20309842)
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| Project Period (FY) |
2000 – 2002
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| Project Status |
Completed (Fiscal Year 2002)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2002: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2001: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | transcranial magnetic stimulation / inflammation / hyperalgesia / complete Freund's adjuvant / Freundアジュバント / 神経因性疼痛 / 長期増強(LTP) / NMDA 受容体 / 痛覚過敏 / アロディニア |
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| Research Abstract |
Neuropathic pain is often resistant to conventional treatments. Electroconconvulsive treatment (ECT) has been tried in refractory cases, but is still invasive even if performed under general anesthesia. Transcranial magnetic stimulation (TMS) which can stimulate cortical brain regions without pain or convulsion has been reported to be beneficial in treating with some neurological or psychiatric disorders. We examined the effect of TMS on pain behavior in a rat model of chronic inflammation to evaluate a therapeutic potential of TMS in pain control.
Injection of complete Freund's adjuvant (CFA) into one hindpaw elicited both thermal and mechanical hyperalgesia in a bi-phasic fashion : the early phase was 1-2 days after and the late phase 5-12 days after the injection. TMS applied for 30 min with a frequency of 0.1 Hz and a strength of 0.7 tesla did not depress either thermal or mechanical hyperalgesia in the early phase. In the late phase, TMS at the same stimulation mode depressed thermal hyperalgesia for 6 hrs to 2 days after the stimulation, without affecting withdrawal latencies of the non-inflamed paw to radiant heat stimuli. Difference scores of both hindpaws were 3.3 ±0.8 s prior to and 0.6 ± 1.5 s (n =10) 1 day after TMS, respectively. TMS, applied at 2 Hz for 10 s and repeated 5 times at 1 min intervals, also depressed thermal hyperalgesia. The difference scores were 3.7±0.7 s prior to and 1.1±1.1 s (n=8) 1 day after the TMS. Mechanical hyperalgesia in the late phase was not depressed by TMS applied at either stimulation modes.
Thus, the present study has demonstrated that thermal hyperalgesia evoked in a rat chronic inflammatory pain model can be restored temporarily for 2 days after a single session of TMS, while mechanical hyperalgesia is not affected. Our results raise a possibility of TMS as a promising therapeutic intervention in the treatment of refractory pain.
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