Neuroimaging: visualising the brain in pain.

The neuroimaging of experimental and clinical pain has revolutionised our understanding of the physiological responses to pain and paved the way for a better understanding of the pathophysiology of chronic pain syndromes. Extensive research on the central mechanisms regarding the sensory-discriminative dimensions of pain have revealed a complex network of cortical and subcortical brain structures involved in the transmission and integration of pain, the so-called pain matrix. Although brain imaging and pharmacological studies have generated some insight into the circuitry that may be involved in the generation of chronic pain symptoms, further research into brain imaging of chronic pain is clearly warranted. However, modern neuroimaging suggests that the chronification of pain (and headaches) involves functional and structural plasticity of both the central and peripheral nervous system.