著者

池本 竜則 牛田 享宏 谷口 慎一郎 谷 俊一 森尾 一夫 佐々木 俊一 Zinchuk Vadim 田中 茂樹

出版者

日本疼痛学会

雑誌

PAIN RESEARCH (ISSN:09158588)

巻号頁・発行日

vol.19, no.3, pp.107-112, 2004-07-31 (Released:2014-02-20)

参考文献数

9

---

It is widely known that sensation of the pain is derived from sensory-discriminative factor and emotional factor. Especially in chronic pain, emotional factors and psychosocial backgrounds are more likely to contribute for the patients' discomfort. The aim of this study is to investigate how emotional factor of pain participates in intractable pain. We employed fMRI to compare the brain activations occurring in the orthopaedic neuropathic pain patients with allodynia and normal individuals in response to the visual virtual painful experience. During fMRI scanning, a video demonstrating an actual tactile stimulation of the palm and its imitation were shown to participants. In contrast to normal individuals,allodynia patients also displayed activation of the areas reflecting emotions: frontal lobe and anterior cingulate. These findings suggest that brain have important role in the development and maintaining of peripheral originated chronic painful condition.

著者

池本 竜則 牛田 享宏 谷口 慎一郎 谷 俊一 森尾 一夫 佐々木 俊一 田中 茂樹

出版者

日本疼痛学会

雑誌

PAIN RESEARCH (ISSN:09158588)

巻号頁・発行日

vol.21, no.3, pp.117-125, 2006-08-20 (Released:2013-10-24)

参考文献数

36

被引用文献数

2 1

---

Using functional magnetic resonance imaging (FMRI) technology, we investigated the difference of pain related brain cortical activation derived from noxious stimulation to the skin and muscular tissue. Ten healthy volunteers who have no history of brain vascular disease were enrolled in this study. A cutaneouos pain was provoked by isotonic (0.9%) saline injection into intradermal space on right lower leg through 24G plastic catheter, and a muscle pain was provoked by hypertonic (3%) saline injection into right tibialis anterior muscle. We used event-related FMRI to measure brain activity during each injection. Visual analogue scale (VAS) was used to quantify pain intensity and unpleasantness, and pain quality was assessed with several verbal descriptions. Results: Pain unpleasantness rating was higher in the muscle pain compared to the cutaneous pain,despite the same pain intensity rating. The cutaneous pain had more acute pain onset than the muscle pain. Pain duration after stimulation was short in the cutaneous pain, but long in the muscle pain. The extent of the painful region tended to be larger with the muscle pain, but there was no statistical significance. Evoked FMRI response from the cutaneous pain showed distinct brain activation in the inferior and superior parietal cortex (BA: Brodmann area 5/7/40), primary and secondary somatosensory cortex (S1 & S2), insula, supplementary motor area (SMA, BA6), posterior cingulate cortex and cerebellum. On the other hand, FMRI response from muscle pain showed distinct brain activation mainly in the contralateral insula. These results suggest that the parietal lobe including the S1 is the essential area for cognition of sharp and well-localized pain conditions such as cutaneous pain, and may not be essential for cognition of diffuse pain derived from muscular tissue.

著者

池本 竜則 牛田 享宏 谷口 慎一郎 谷 俊一 森尾 一夫 佐々木 俊一 田中 茂樹

出版者

日本疼痛学会

雑誌

PAIN RESEARCH (ISSN:09158588)

巻号頁・発行日

vol.20, no.3, pp.111-115, 2005-08-26 (Released:2014-01-16)

参考文献数

9

被引用文献数

1 3

---

We employed the functional MRI (fMRI) to investigate the changes of brain activation after reducing of capsaicin-induced heat hyperalgesia. Eight healthy volunteers who have no history of brain vascular disease were enrolled in this study. Capsaicin-induced heat hyperalgesia was developed by topical application of 2% capsaicin cream to anterior surface of left forearm. First fMRI time series were taken an hour after the application of capsaicin and second fMRI time series were taken an hour after medication (Loxoprofen Na: 120 mg). As for the pain task, 45°C wet cotton was put on the region where the heat hyperalgesia was evoked by capsaicin cream. Results of first fMRI time series showed distinct activation in the thalamus, anterior cingulate cortex, supplementary motor area, and prefrontal cortex. An hour after medication, though heat hyperalgesia still remained, all participants reported improvement of pain discomfort (VAS 4.7 to 2.5). Second series fMRI showed activation only in the thalamus. These results suggest that deactivated areas (anterior cingulate, etc.) observed after medication might be involved mainly in the pain related discomfort.