Phantom pains and strange sensations torture soldiers after amputations, civilians who lose limbs in accidents and thousands of innocent people who have lost body parts through landmines left behind after wars. This baffling phenomenon puzzled doctors for the longest time, since there seemed to be no physical cause. Remember, the conventional knowledge at the time regarding the brain map was that there had to be an ongoing pain stimulus arriving at the brain, in order for the brain to interpret it as pain.
“Normal” or acute pain - such as sustained when you break your arm in a fall, is useful in that it sends a message to the brain saying - “this hurts, stop using me, please do something!” Sometimes however, the damage to the tissues and nerves sets up a problem with the entire pain system, which causes ongoing sensations of pain, long after the tissues have healed.
With amputations, doctors used to think that the pain was occurring due to nerve endings in the stump end of the amputated limb being triggered by movement. Unfortunately, the practice developed of performing further amputations, cutting the limb and its nerves, farther and farther back. But after each surgery, the phantom pain would always come back, much to the frustration of the surgeons, and despair of the patient.
What has happened, is that the pain process itself has been altered, and constant alarm signals are firing, making it feel as if the problem is in the affected area, when it is actually in the brain. So, long after the body has repaired itself (often with surgical intervention), the acute pain persists. Phantom limbs don't just feel painful, but often have a life of their own. Many patients report feeling as if the limb is gesticulating while they talk, reaching out to answer a phone or trying to brush their hair.
V.S. Ramachandran, a neurologist of Hindu background, was born in Madras, India and trained in Cambridge, England. He later became the Director of the Centre for Brain and Cognition at the University of California. He is a leader in using neuroplasticity to reconfigure the content of our minds and has shown how the brain can be rewired by relatively brief and simple treatments without any high tech equipment.
He had the theory that phantoms were caused by rewired brain maps. To test the theory, he blindfolded a man who had lost his arm in a motor vehicle crash. He touched different parts of “Tom’s” body with a Q-tip - asking him what he felt each time. When he touched Tom’s cheek, Tom reported that he felt the Q-tip touching his cheek, but that it also felt like it was touching his amputated limb. When he touched Tom’s upper lip, the sensation was felt there and in Tom’s index finger of the phantom limb!
Following up these findings with a brain scan, the scan confirmed what Dr Ramachandran had already discovered with his Q-tip - that the hand map in Tom’s brain was now being used to process facial sensations. Essentially the hand maps and face maps in his brain had blurred together!