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The first accounts of phantom limbs came from a man by the name of S. Weir Mitchell who observed Civil War amputees at a hospital in Philadelphia. He wrote a book about his curious dealings with amputees, some of who insisted that they could still feel their amputated limb. His accounts were the first documented cases of phantom limbs. There has now been extensive study of the phantom limb sensation but technology limits what can be learned from direct physical study of the brain, thus the theories of phantom sensation all arise from the analysis of case studies. Here are some interesting facts about phantom sensations:
•Approximately 80% of amputees have some phantom limb sensations.
•The phantom sensation can occur right after the amputation or many months or years later.
•Phantom pain are not typically experienced by children under the age of 4.
•Intensity, duration, severity, quality and chroncity all are variable and are not static from patient to patient.
•Many phantom limb sensations occur after some injury to the site of the amputation. Thus, a person who was born without a limb, and did not experience any type of phantom sensation could suddenly find themselves experiencing one if some type of injury occurred to the stump.
•Phantom limbs help with the use of prosthetics. It's easier to use some type of prosthetic device if there are phantom sensations associated with the limb.
This case study begins with a 43 year old woman who had her right arm amputated slightly above her elbow. She had phantom limb sensations and could move her both her phantom limb and phantom fingers. The limb was felt to move spatially in relation to her other non-amputated limb, and would move correctly when she walked. The only difference in feeling in the phantom limb from her other arm was that it felt colder. As a year progressed the phantom limb sensations started to fade. The fingers and hand were felt to move closer to the stump.
This occurred in response to an amputation. She had the sensation of someone touching her phantom hand at certain points when her face was touched.
A year after the first interview, the woman was interviewed again in a follow-up. The cortical remapping that had first taken place the previous year had seemingly continued. The sensation of touching her hand when the right side of her face was touched had now also moved to the left side of her face! Now bilateral stimulation of her face could produce sensations in her phantom arm. The thumb of the phantom hand was felt to be touched when any number of places on the face were stimulated. This was also true for the other fingers.
Some other information about this woman's case:
•The subject's phantom hand was represented on a topographic map of the facial region.
•There was a time lag of about 5.6 seconds between touching the left side of the face and the subsequent feeling in the hand.
•The time lag was only 1.8 seconds when the right side of the face was stimulated.
•The feeling of the phantom limb being touched was more vivid when the left side of the face was stimulated than with the right side.
•When the subject's pinkie was moved passively, there was subsequent synchrony of movement in the phantom pinkie.
•There was no sensation in the non-amputated hand when the face was stimulated.
This case study involves a 29 year old male who was born with deformed arms and legs. Both of his wrists are attached directly to the elbow joint and the foot and ankle on both legs are attached directly to the knee joint. He wears prostheses on his legs but not on his arms. He had never felt any type of phantom sensations until surgery was performed on his legs to remove cysts. The surgery involved both of his lower limbs. After the surgical procedure, he experienced phantom sensations in his legs. He feels as if he has full length phantom legs that fill his prostheses and that he stands on phantom feet. He can also feel his intact feet at knee level, but they feel as if they have moved away from his knees. After three years, the phantom sensations have not abated, and no painful sensations were felt in them.
•In this case the phantom limbs help with the use of the prosthetic legs. The phantom legs can "feel" the floor and produce more natural
