Pathophysiology+Cancer+Pain

toc =**Pathophysiology of Cancer Pain**= =**Causes of Cancer Pain**= =**Neuropathic Pain**= =**Inflammatory Pain**= =**Visceral Pain**= =**Cancer-Induced Bone Pain**= =**Cancer Therapy-Induced Pain**=
 * Cancer pain has the same pathophysiology as non-cancer pain.
 * Rarely a purely visceral, somatic or neuropathic pain.
 * It may involve inflammation, neuropathic, ischemic, and compressive mechanisms.
 * Tumor expansion causing pressuring, secretion of inflammatory and pro-hyperalgesic mediators, tumor infiltration of nerve plexuses resulting in damage, metastatic spread to bone, stretching of hollow viscera, distortion of solid organs, ischemia and necrosis resulting in nociceptive pain.
 * Cancer treatment including joint pain caused by hormonal and chemotherapy, mucositis, postradiation plexopathies, polyneuropathy, surgical intervention and nerve damage.
 * Arise from neurons that are damaged, can be either peripheral or central.
 * Peripheral damage alters expression of sodium and calcium channels at the site of injury via alteration in gene expression. These damaged neurons fire spontaneously resulting in recruitment of silent nociceptors.
 * Overall effect is hyperexcitation with increased receptive fields, primary and secondary hyperalgesia, and allodynia.
 * Both peripheral and central inflammatory modulators increase signaling and result in sensitization of primary afferents. Inflammatory mediators include – bradykinins, nerve growth factor, cytokines, ATP, and protons. This results in stimulation of silent nociceptors and peripheral hyperalgesia.
 * Stimuli for visceral pain include: chemical, ischemic inflammatory, compression, and distension-contraction.
 * Bone is highly innervated, pain is triggered by inflammatory infiltrate secondary to invasion of cancer cells and primary destruction by osteoclast activation resulting in hyperexcitation of the dorsal horn of the spinal cord.
 * Taxol, for example, disrupts microtubular aggregation, it accumulates in the dorsal root ganglia, and activates a neuro-immune reaction which results in neuropathic pain.

include component="editors" days="30" imageSize="small" showUsername="true" include component="comments" page="Pathophysiology Cancer Pain" limit="10" media type="googleplusone" key="" width="450" height="24" align="left"media type="digg" key="http%3A%2F%2Fetherpedia.wikispaces.com%2Fspace.template.etherpedia%20wiki%20page" width="50" height="64" align="left"media type="reddit" key="" width="120" height="22" align="left"