Pain special cases
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Pain special cases On the Web |
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American Roentgen Ray Society Images of Pain special cases |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Special cases
Phantom pain
Phantom pain is the sensation of pain from a limb or organ that has been lost or from which a person no longer receives physical signals.Phantom limb pain is an experience almost universally reported by amputees and quadriplegics. Phantom pain is a neuropathic pain.
Sometimes, when a limb is removed during an amputation, an individual will continue to have an internal sense of the lost limb. This phenomenon is known as phantom limb and accounts describing it date back to the 1800s. Similarly, many amputees are frequently aware of severe pain in the absent limb. Their pain is real and is often accompanied by other health problems, such as depression.
What causes this phenomenon? Scientists believe that following amputation, nerve cells "rewire" themselves and continue to receive messages, resulting in a remapping of the brain's circuitry. The brain's ability to restructure itself, to change and adapt following injury, is called plasticity (see section on Plasticity).
Our understanding of phantom pain has improved tremendously in recent years. Investigators previously believed that brain cells affected by amputation simply died off. They attributed sensations of pain at the site of the amputation to irritation of nerves located near the limb stump. Now, using imaging techniques such as positron emission tomography (PET) and magnetic resonance imaging (MRI), scientists can actually visualize increased activity in the brain's cortex when an individual feels phantom pain. When study participants move the stump of an amputated limb, neurons in the brain remain dynamic and excitable. Surprisingly, the brain's cells can be stimulated by other body parts, often those located closest to the missing limb.
Treatments for phantom pain may include analgesics, anticonvulsants, and other types of drugs; nerve blocks; electrical stimulation; psychological counseling, biofeedback, hypnosis, and acupuncture; and, in rare instances, surgery.
Pain asymbolia
Pain science acknowledges, in a puzzling challenge to IASP definition,[1] that pain may be experienced as a sensation devoid of any unpleasantness: this happens in a syndrome called pain asymbolia or pain dissociation, caused by conditions like lobotomy, cingulotomy or morphine analgesia. Typically, such patients report that they have pain but are not bothered by it, they recognize the sensation of pain but are mostly or completely immune to suffering from it.[2]
Insensitivity to pain
The ability to experience pain is essential for protection from injury, and recognition of the presence of injury. Insensitivity to pain may occur in special circumstances, such as for an athlete in the heat of the action, or for an injured soldier happy to leave the battleground. This phenomenon is now explained by the gate control theory. However, insensitivity to pain may also be an acquired impairment following conditions such as spinal cord injury, diabetes mellitus, or more rarely Hansen's Disease (leprosy).[3] A few people can also suffer from congenital insensitivity to pain, or congenital analgesia, a rare genetic defect that puts these individuals at constant risk from the consequences of unrecognized injury or illness. Children with this condition suffer carelessly repeated damages to their tongue, eyes, bones, skin, muscles. They may attain adulthood, but they have a shortened life expectancy.
Psychogenic pain
Psychogenic pain, also called psychalgia or somatoform pain, is physical pain that is caused, increased, or prolonged by mental, emotional, or behavioral factors.[4][5] Headache, back pain, or stomach pain are some of the most common types of psychogenic pain.[4] Sufferers are often stigmatized, because both medical professionals and the general public tend to think that pain from a psychological source is not "real". However, specialists consider that it is no less actual or hurtful than pain from other sources.
References
- ↑ See IASP Pain Terminology. The whole entry on the term pain itself reads like this:
Pain. An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage. Note: The inability to communicate verbally does not negate the possibility that an individual is experiencing pain and is in need of appropriate pain-relieving treatment. Pain is always subjective. Each individual learns the application of the word through experiences related to injury in early life. Biologists recognize that those stimuli which cause pain are liable to damage tissue. Accordingly, pain is that experience we associate with actual or potential tissue damage. It is unquestionably a sensation in a part or parts of the body, but it is also always unpleasant and therefore also an emotional experience. Experiences which resemble pain but are not unpleasant, e.g., pricking, should not be called pain. Unpleasant abnormal experiences (dysesthesias) may also be pain but are not necessarily so because, subjectively, they may not have the usual sensory qualities of pain. Many people report pain in the absence of tissue damage or any likely pathophysiological cause; usually this happens for psychological reasons. There is usually no way to distinguish their experience from that due to tissue damage if we take the subjective report. If they regard their experience as pain and if they report it in the same ways as pain caused by tissue damage, it should be accepted as pain. This definition avoids tying pain to the stimulus. Activity induced in the nociceptor and nociceptive pathways by a noxious stimulus is not pain, which is always a psychological state, even though we may well appreciate that pain most often has a proximate physical cause.
- ↑ Nikola Grahek, Feeling pain and being in pain, Oldenburg, 2001. ISBN 3-8142-0780-7.
- ↑ Brand, Paul (c1997). The gift of pain : why we hurt & what we can do about it. Zondervan Publ. ISBN 0-310-22144-7. Unknown parameter
|coauthors=ignored (help); Check date values in:|date=(help) - ↑ 4.0 4.1 Clinic, Health information
- ↑ "Psychogenic pain - definition from Biology-Online.org". Biology-online.org. Retrieved 2008-11-05.