Can you imagine having one your your arms or legs amputated? The horror of losing a body part probably stays with you forever. Amputations are not done for fun, though. Its usually to save someone's life. But how scary must it be to wake up one morning thinking "Wow my leg really hurts! I wonder what's wrong with- Darn it! I forgot! I don't have a leg!"
This is the phenomenon of Phantom Limb Syndrome. Almost all amputees report feeling pain or other sensations in the limb that has been amputated. Scientists used to think that this was due to damaged nerve endings in the stump sending weird signals to the brain. They used to amputate more of the stump in order to remove the damaged nerves. This, as we now know, would not help the patients. In fact, it would cause more phantom limb pains!! Phantom Limb Syndrome is actually due to the rewiring of the brain's somatosensory cortex. Since the person no longer has a certain limb, all the space in the brain dedicated to that limb is now a waste. So, the brain rewires that area to correspond to another body part. The homunculus is a representation of the post-central gyrus and the are of the body that it receives sensory information from.
This is the phenomenon of Phantom Limb Syndrome. Almost all amputees report feeling pain or other sensations in the limb that has been amputated. Scientists used to think that this was due to damaged nerve endings in the stump sending weird signals to the brain. They used to amputate more of the stump in order to remove the damaged nerves. This, as we now know, would not help the patients. In fact, it would cause more phantom limb pains!! Phantom Limb Syndrome is actually due to the rewiring of the brain's somatosensory cortex. Since the person no longer has a certain limb, all the space in the brain dedicated to that limb is now a waste. So, the brain rewires that area to correspond to another body part. The homunculus is a representation of the post-central gyrus and the are of the body that it receives sensory information from.
An individual who has lost their arm, usually has the hand area taken over by the face area. Someone who has lost a leg sometimes has the leg area taken over by the genital area! Because of this, if someone felt a sensation on their face, for example, they would also feel it on their phantom arm. This video explains the phenomenon of phantom limb syndrome very clearly.
Phantom pain can also occur in people who were born without a certain limb. This is because the nerves that would usually innervate the missing limb cause pain.
There are many treatments for phantom limb syndrome including medication and therapy. One treatment that is very interesting is the mirror box treatment developed by V.S. Ramachandran. It involves having the patient sit next to a mirror with the amputated stump hidden from view. The limb on the other side is seen in the mirror and looks like the patient has both limbs. The patient moves the limb and in the mirror it looks like both limbs are moving. This can help the patient reposition the phantom limb in less painful positions, or unclench.
This video shows that phantom sensations can be induced in people who haven't had amputations. This is more of an illusion than the actual rewiring of the brain that happens in phantom limb syndrome but it produces similar effects.
This topic is very interesting and I am glad that we were able to cover it in this chapter and that you were able to provide more information in your blog. It is remarkable how our brain works when it has to rewire itself in order to correspond to another part. As a future occupational therapist student, I know I would be working with people with Phantom Limb Syndrome and would have to provide therapy to adjust to daily life activities. I wonder if anyone can get certified to use the mirror box treatment?
ReplyDeleteThis is a very interesting topic, that you wrote about, I’d heard of phantom limb pains from my always reliable source (my TV), but I never really know what it was really about, just the basics. Reading your post made everything so easy to understand and learning more about these pains and how and why they happen was great. Learning that they doctors amputated more to help cure these pains was something wowed me, just made me wonder what they were thinking. The mirror box treatment was also something that intrigued me.
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