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Published on: January 21, 2020
Central representation of hyperalgesia from myofascial trigger point
David M Niddam1, Rai-Chi Chan, Si-Huei Lee
1Brain Research Center, National Yang-Ming University, Taipei, Taiwan. niddam@vghtpe.gov.tw
Neuroimage
|November 15, 2007
Summary
Myofascial pain syndrome (MPS) patients exhibit abnormal brain responses to pain stimuli. Research shows heightened activity in sensory and emotional brain regions, suggesting a link between pain processing and stress.
Area of Science:
- Neuroscience
- Pain Medicine
- Medical Imaging
Background:
- Myofascial pain syndrome (MPS) is a common chronic pain condition.
- The underlying neurobiological mechanisms of MPS, particularly brain responses to pain, require further investigation.
Purpose of the Study:
- To investigate abnormal brain responses to pain in patients with MPS.
- To characterize the brain's response to pain evoked from myofascial trigger points (MTPs) using functional magnetic resonance imaging (fMRI).
Main Methods:
- Event-related fMRI was employed to compare brain activation patterns in MPS patients and healthy controls.
- Stimuli were applied to hypersensitive MTPs in patients and equivalent sites in controls, with both stimulus and pain intensity matched.
Main Results:
- MPS patients reported significantly higher pain intensity (hyperalgesia) at matched stimulus intensity compared to controls.
- Brain imaging revealed enhanced somatosensory (SI, SII, inferior parietal, mid-insula) and limbic (anterior insula) activity in patients.
- Suppressed right dorsal hippocampal activity was observed in MPS patients compared to controls at matched stimulus intensity.
Conclusions:
- The hyperalgesic state in MPS is associated with abnormal hyperactivity in brain regions involved in processing stimulus intensity and negative affect.
- Suppressed hippocampal activity may indicate stress-related changes due to chronic pain acting as a physical and emotional stressor.
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