Bolay H, Moskowitz MA. Mechanisms of pain modulation in chronic syndromes. Neurology. 2002 Sep 10;59(5 Suppl 2):S2-7. Transmission of pain from the periphery to the cortex depends on integration and signal processing within the spinal cord, brainstem, and forebrain. Sensitization, a component of persistent or chronic pain, may develop either through peripheral mechanisms or as a consequence of altered physiology...