Ways to classify pain ► Acute vs. chronic ► Nociceptive vs. neuropathic ► Psychogenic vs. somatic
Acute vs. Chronic Acute Cause is known Function is protective Increased autonomic activity Short duration, resolves with healing Inflammation, tissue injury Short term upregulation of pain sensitivity Chronic Cause = ? No protective function None Does not resolve with healing None Long term changes including allodynia, hyperalgesia, etc.
Nociceptive vs. Neuropathic ► Nociceptive: Appropriate stimulation of nerve endings leads to signaling ► Neuropathic: Dysfunction of nerve
Acute, nociceptive pain ► Examples? ► Goals of treatment Heal the injury Decrease acute pain Prevent progression to chronic pain ► Strategies
Acute, neuropathic pain ► Migraine, herniated disk
Chronic, nociceptive pain ► Arthritis, cancer ► BOTH ongoing damage and upregulation of nerve impulses ► Remodeling centrally and dorsal horn of spinal cord ► Multimodal treatment
Chronic, neuropathic pain ► Fibromyalgia, IBS ► Not much utility to anti-inflammatories ► Neuromodulating agents are key
► Musculoskeletal symptoms and non-REM sleep disturbance in patients with "fibrositis syndrome" and healthy subjects. ► Moldofsky, et al, Psychosomatic Medicine, 1975, 37 (4):
► ► Smith et al. The effects of sleep deprivation on pain inhibition and spontaneous pain in women. Sleep The effects of sleep deprivation on pain inhibition and spontaneous pain in women. ► ► Kundermann et al. The effect of sleep deprivation on pain. Pain Res Manag. 2004The effect of sleep deprivation on pain.