There is a difference between 'phantom sensations' and 'phantom pain'. Phantom sensations can feel like an itch you can't scratch, or the feeling that you can wiggle your toes. Caution should be used at this time as you could accidently take a step thinking your leg is still there. Phantom pain is the opposite. It is an extremely painful experience. It can begin like a cramp and steadily increase in intensity. Or it can hit you without any warning. This has happened to me many times. For some, putting ice on your stump will relieve the pain, walking, moving about will also help eliminate some of it. If the pain is too much to deal with, immediately consult your physician. There are medications to help deal with this painful process.
~LadyAmp
U. C. San Diego Neurobiologist at Forefront of Phantom
Research
Richard Mooney, Mutual Amputee Aid Foundation, with V S.
Ramachandran, M.D., Ph.D., University of California, San Diego
with permission 3/2000
Compared to some medical conditions,
phantom limb sensation is a relatively modern phenomenon. This is because
amputation was not widely practiced - at least not successfully - until the
Civil War. However, almost every amputee has experienced the phenomenon - many
quite vividly.
The first known reference to phantom sensation (and
related pain) didn't appear in a medical journal but in the Atlantic Monthly in
1866, when the story of civil War veteran, George Dedlow, appeared. Since then,
spurred on by their patients' pain that often accompanies the phantoms and the
urgent need to find effective treatments for it, physicians and researchers have
developed and tested many different theories about where phantoms originate and
why. Although scientific research has solved many other perplexing medical
puzzles during the last 100 years, phantoms still remain a relative
mystery.
It was originally thought that phantoms and the pain which is
often associated with them originated in the stump, perhaps as a result of
neuromas that tend to form at the ends of severed nerves. If that were true,
however, there would be no explanation for the fact that many congenital
amputees - people who neither had severed nerves nor had they ever experienced
having real arms or legs - frequently experience phantom sensations. Neither
would it explain phantom vision experienced by many people who suffer vision
loss due to cataracts or retina degeneration, or phantom hearing experienced by
many people who lose their "real" hearing.
The only sensible explanation
is that phantoms occur, not in the limbs, but in the brain. If that is the case,
then much of the pain must also originate in the brain. (I should emphasize that
phantom pain is a physiological, not psychological phenomenon.
Clearly, phantom pain is not imaginary!)
In the "normal,"
four-limbed body, sensations experienced by the "receptor" nerves in the hands,
arms, feet, and legs are sent to the spinalcord over a network of "transmission"
nerves. The spinal cord is kind of a "neural superhighway" up which all these
signals travel to the brain. The signals are received deep within the brain by
the thalamus, a kind of "relay station" that routes the signals through its
specialized circuits that are assigned to handle signals from each part of the
body. The thalamus then reintegrates the signals and sends them on to the
somatosensory cortex - the part of the brain that converts them to sensations we
interpret as hot, cold, rough, smooth, etc.
Research done in the 1960s
suggested that the brain was "hard wired," that is, its internal connections
were fixed in place, something like the electrical wiring in a house. If that
were the case, then when a limb is amputated, no signal from it would reach the
brain and that would be that - something like having the person on the other end
of a phone conversation hang up.
"But that isn't what happens, " Dr.
Ramachandran asserts. "My research, and that of my colleagues at U.C. San
Francisco, Vanderbilt University, and elsewhere, has revealed that the brain
somehow 're- wires' itself so that when the 'wires are cut' between a thumb, for
example, and the part of the brain that listens for thumb signals, that part of
the brain doesn't just sit there listening to a 'dead line' as it would if the
brain were hard wired. Instead, as happens with many amputees, those brain parts
rewire to next-door brain parts, which in the human body, happen to be those
that listen for face signals. Thus, if I touch a certain part of a
patient's face with a Q-Tip, he is very likely to feel his phantom
thumb!
"A lot of my work with arm amputees involves charting those 'face
maps' in detail. Once I can connect specific areas of the face with specific
areas of the absent hand, I can then create 'brain maps' using a technique known
as 'Functional Magnetic Resonance Imaging.' Through this process, we are
learning many new things about how the human brain works. This should eventually
provide valuable insight into how people recover from brain injuries, how we
learn, and of course, how phantom pain occurs and how to treat it
effectively.
"So far, we've learned a little about phantom pain. I
suspect the motor command centers of the brain may be one of the causes of it.
For example, the motor command center may send signals to a missing hand,
telling it to move. In absence of feedback telling the brain that the hand has
done what was commanded, the brain may literally flood the neural pathwayswith
more 'move' signals - much more and more forcefully than normal. The brain may
perceive this 'flood' as pain.
"Certainly, much more needs to be learned
before we can explain phantom pain with certainty. The exciting part of my
research for amputees is that if the phantoms are in the brain, then the answer
to the pain may be there too."
Professor Ramachandran is
the head of the Brain and Perception Laboratory in the Department of Psychology
at the University of California at San Diego.
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