Phantom limb | |
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A cat attempting to use its left foreleg to scoop litter several months after it has been amputated | |
Classification and external resources | |
Specialty | neurology |
ICD-10 | G54.6-G54.7 |
ICD-9-CM | 353.6 |
DiseasesDB | 29431 |
MeSH | D010591 |
A phantom limb is the sensation that an amputated or missing limb is still attached. Approximately 60 to 80% of individuals with an amputation experience phantom sensations in their amputated limb, and the majority of the sensations are painful. Phantom sensations may also occur after the removal of body parts other than the limbs, e.g. after amputation of the breast, extraction of a tooth (phantom tooth pain) or removal of an eye (phantom eye syndrome).
Although not all phantom limbs are painful, people will sometimes feel as if they are gesturing, feel itches, twitch, or even try to pick things up. The missing limb often feels shorter and may feel as if it is in a distorted and painful position. Occasionally, the pain can be made worse by stress, anxiety, and weather changes. Phantom limb pain is usually intermittent. The frequency and intensity of attacks usually declines with time.
Some people who have undergone gender reassignment surgery have reported the sensation of phantom genitals. The reports were less common among post-operative transwomen, but did occur in transmen. Similarly, subjects who had undergone mastectomy reported experiencing phantom breasts; these reports were substantially less common among post-operative transmen, but did occur in transwomen.
Phantom limb pain (PLP) is a complex phenomenon that includes a wide variety of symptoms ranging from tingling and itching to burning and aching.
Until recently, the dominant hypothesis for the cause of phantom limbs was irritation in the severed nerve endings (called "neuromas"). When a limb is amputated, many severed nerve endings are terminated at the residual limb. These nerve endings can become inflamed, and were thought to send anomalous signals to the brain. These signals, being functionally nonsense, were thought to be interpreted by the brain as pain. Treatments based on this hypothesis were generally failures. In extreme cases, surgeons would perform a second amputation, shortening the stump, with the hope of removing the inflamed nerve endings and causing temporary relief from the phantom pain. But instead, the patients' phantom pains increased, and many were left with the sensation of both the original phantom limb, as well as a new phantom stump, with a pain all its own. In some cases, surgeons even cut the sensory nerves leading into the spinal cord or in extreme cases, even removed the part of the thalamus that receives sensory signals from the body.