Types of Pain & Pain Disorders

 

 

Chronic Pain Definition

There are many definitions for chronic pain, The Institute for Clinical Systems Improvement 's Health Care Guideline Assessment and Management of Chronic Pain (2013) defined chronic pain as "pain without biological value that has persisted beyond the normal time and despite the usual customary efforts to diagnose and treat the original condition and injury." If a patient's pain has persisted for six weeks (or longer than the anticipated healing time), a thorough evaluation for the course of the chronic pain is warranted. They defined the chronic pain syndrome as a constellation of behaviors related to persistent pain that represents significant life role disruption.

Types of Pain

There are many ways to classify pain, but many divide pain into two (2) broad categories--nociceptive and neuropathic--with various sub-classifications.

 Nociceptive pain refers to pain experienced with damage or injury to skin, muscles, joints, tendons, bones, or internal (visceral) organs. As the body heals and inflammation subsides, pain lessens; medical treatments aim to reduce inflammation (e.g. with medications) or to repair conditions causing pain (e.g. joint replacement).

 Neuropathic pain refers to caused by damage or disease within the nervous system such as can pain caused by diabetic never damage (i.e. neuropathy), post-herpetic ( i.e. shingles) neuralgia, multiple sclerosis pain, pinched nerves (e..g. sciatica), or phantom leg pain. The central nervous system processes all pain signals, either the origin by nociceptive, neuropathic, or both. 

Central pain processing- Since pain is processed in the central nervous system, no one experiences pain in exactly the same way. As an example, women in their 80's invariably are shorter than they once were do to osteoporosis, arthritis, and degenerative disc disease, but many complain of only mild pain and do not use medications despite these conditions. Many younger people with far less "objective" evidence of pathology on MRI are disabled by pain. No person can judge or measure another person's pain.

Chronic Pain Disorders

Chronic pain disorders are often complex involving multiple pain generators (e.g. joint inflammation) and central nervous system pain processing. Sometimes medical therapies themselves contribute to pain, such as complications from surgery or from medication treatment. Since chronic pain is often complex, multidisciplinary treatment is usually indicated and supported by scientific evidence as better than routine care. Examples of chronic pain disorders include: 

"Failed back" or "post-laminectomy" syndrome: This term is used to describe a condition when spinal surgery does not achieve desired results and pain persists. It may be due to scar tissue, structural changes in the spine, sacroiliac joint dysfunction , or problems that may have been overlooked before surgery. 

Opioid-induced hyperalgesia: Opioid (narcotic) medications may themselves increase pain due to a condition called opioid-induced hyperalgesia. For reasons not fully understood, some people who receive high dose opioid treatment for pain develop increased pain sensitivity and a decreased pain threshold. This reason, all recent opioid prescribing guidelines advise against high dose treatment. Research has shown that pain decreases and function improves through program participation in comprehensive pain programs that include withdrawal of opioid therapy. 

Persistent Radiculopathy: This condition results when one or more nerves is "pinched" at or near the root of the nerve along the spine. Pain and other symptoms radiate to the part of the body served by that nerve. Sciatica is an example of a radiculopathy, an impingement of the sciatic nerve in the low back that may result in leg pain, muscle weakness, and loss of reflexes. Sometimes radiculopathy is chronic, despite medications, physical therapy, injections, or surgery. 

Chronic Migraine: The International Headache Society defines chronic migraine as more than 15 headache days per month over a three month period of which more than eight are migraines, in the absence of medication over-use. A combination of medical treatments, lifestyle changes and understanding the migraine triggers is important

Complex Regional Pain Syndrome: Also known as regional sympathetic dystrophy (RSD), is a debilitating, painful condition in a limb, associated with abnormal sensation, decreased muscle strength as well as skin and bone abnormalities. A recent treatment guideline (RCP- UK 2012) recommends. ... an integrated, interdisciplinary treatment approach... tailored to the individual patient. The primary aims are to reduce pain, preserve or restore function, and enable patients to manage their condition and improve their quality of life. The four "pillars" of care are: education, pain relief, physical rehabilitation and psychological intervention.