Review of neuroimaging studies related to pain modulation

摘要: Abstract Background and purpose A noxious stimulus does not necessarily cause pain. Nociceptive signals arising from a are subject to modulation via endogenous inhibitory facilitatory mechanisms as they travel the periphery dorsal horn or brainstem on higher brain sites. Research neural structures underlying pain has largely been restricted animal research due invasiveness of such studies (e.g., spinal cord transection, lesioning, site stimulation). Neuroimaging techniques magnetoencephalography (MEG), positron emission tomography (PET) functional magnetic resonance imaging (fMRI)) provide non-invasive means study in humans. The aim is narrative review neuroimaging related human control mechanisms. Methods approach taken summarise specific within somatosensory (diffuse controls, acupuncture, movement), affective (depression, anxiety, catastrophizing, stress) cognitive (anticipation/placebo, attention/distraction, hypnosis) domains with emphasis contribution studies. Results conclusions Findings complex reflecting activation deactivation numerous areas. Despite this, have clarified supraspinal sites involved number periaqueductal grey (PAG) one area that consistently shown be activated across majority Activity rostral ventromedial medulla known relay descending PAG, also observed both during acupuncture analgesia anxiety-induced hyperalgesia. Other areas appear anterior cingulate cortex, prefrontal orbitofrontal cortex nucleus accumbens, but their exact role less clear. Implications provided essential information about modulatory pathways under normal conditions, much still determined. Understanding important for understanding contribute failed chronic Applying fMRI outside brain, trigeminal caudalis spinotrigeminal pathway cord, coupling activity at these may help improve our function shed light connectivity pathway.