All the information which comes into our sensory system such as feelings like touch and pain is transmitted up to the sensory cortex of the brain, where the parts of the body have specific parts of the cortex dedicated to them. The diagram which results when the body parts are illustrated against the sensory cortex is called the homunculus, in which certain parts such as the lips and hands have much larger areas of brain devoted to them than average. This is because the importance for daily life of those areas is greater and more information is required from them to figure out what's going on.
In an acute injury the injured part goes through an inflammatory process, with the soup of irritating chemicals waking up normally silent pain nerves and a stream of nerves impulses making their way upwards. These enter the spinal cord and pass the messages on to the next stage nerves, which become highly stimulated by the incoming impulse streams as they start to amplify the incoming pain levels. This increases and passes on higher pain intensities up to the brain, forcing us to take corrective actions.
To feel any pain our higher brain areas such as our sensory cortex and our conscious interpreting minds must receive the pain impulses as pain is not present until it gets right through. No pain is imaginary but the brain builds a virtual feeling reality in order to interpret the world and be able to respond, a virtual reality involving sight, touch and pain. It's vital to understand the concept that the brain is what makes the reality of the pain and not the injured, damaged or abnormal body part.
When we have an amputation our nervous system is divided as well as our limb. The bone, muscle and ligaments which are cut through are easy to envisage, but we do not think about the nerves which have to be cut, the consequences of which can be very important. The nervous system does not like parts of it to be removed, it does not like it when an area which normally sends in loads of information suddenly stops doing so. When this occurs odd things start happening in the nervous system, things which can have unpleasant results.
When normal incoming impulses are blocked from reaching the second stage spinal cord nerves these nerves overreact by becoming highly irritable and increasingly active. Due to the nerve transection and the complete loss of sensory input the second stage nerves start to go into business on their own, firing off pain signals without any incoming stimulation. As the sensory areas in the brain for the leg or other amputated part are still present, when they receive the spontaneous inputs from the overexcited second stage nerves they interpret them as pain in the area where the nerve used to come from originally.
Phantom pain is the name given to pain which is present in a part which does not exist any longer. It is a common consequence of amputation with a high proportion of amputees reporting a pain problem which can come on over weeks and months. This pain can be very troubling, more troubling than most typical pains, due to its unpleasant nature which can be very sharp or deep and throbbing. Phantom pain is an example of neuropathic pain, a pain generated by the nervous system rather than by current injury to bodily tissues as in normal pain.
Neuropathic pain is difficult to treat with morphine type drugs such as fentanyl, codeine, morphine or tramadol and more common agents against this sort of pain are gabapentin, amitriptyline and pregabalin. Physical treatment agents such as transcutaneous electrical nerve stimulation may be used by attaching small electrodes to the skin and transmitting pain reducing signals to the central nervous system. Cognitive therapy may be necessary to help patients manage the problems of a long term pain.
Phantom pain can be an intractable, serious problem for anyone with an amputation, and having significant pain before the amputation may make the likelihood of phantom pain greater. A multidisciplinary approach involving a pain clinic is most likely to be helpful. - 14130
In an acute injury the injured part goes through an inflammatory process, with the soup of irritating chemicals waking up normally silent pain nerves and a stream of nerves impulses making their way upwards. These enter the spinal cord and pass the messages on to the next stage nerves, which become highly stimulated by the incoming impulse streams as they start to amplify the incoming pain levels. This increases and passes on higher pain intensities up to the brain, forcing us to take corrective actions.
To feel any pain our higher brain areas such as our sensory cortex and our conscious interpreting minds must receive the pain impulses as pain is not present until it gets right through. No pain is imaginary but the brain builds a virtual feeling reality in order to interpret the world and be able to respond, a virtual reality involving sight, touch and pain. It's vital to understand the concept that the brain is what makes the reality of the pain and not the injured, damaged or abnormal body part.
When we have an amputation our nervous system is divided as well as our limb. The bone, muscle and ligaments which are cut through are easy to envisage, but we do not think about the nerves which have to be cut, the consequences of which can be very important. The nervous system does not like parts of it to be removed, it does not like it when an area which normally sends in loads of information suddenly stops doing so. When this occurs odd things start happening in the nervous system, things which can have unpleasant results.
When normal incoming impulses are blocked from reaching the second stage spinal cord nerves these nerves overreact by becoming highly irritable and increasingly active. Due to the nerve transection and the complete loss of sensory input the second stage nerves start to go into business on their own, firing off pain signals without any incoming stimulation. As the sensory areas in the brain for the leg or other amputated part are still present, when they receive the spontaneous inputs from the overexcited second stage nerves they interpret them as pain in the area where the nerve used to come from originally.
Phantom pain is the name given to pain which is present in a part which does not exist any longer. It is a common consequence of amputation with a high proportion of amputees reporting a pain problem which can come on over weeks and months. This pain can be very troubling, more troubling than most typical pains, due to its unpleasant nature which can be very sharp or deep and throbbing. Phantom pain is an example of neuropathic pain, a pain generated by the nervous system rather than by current injury to bodily tissues as in normal pain.
Neuropathic pain is difficult to treat with morphine type drugs such as fentanyl, codeine, morphine or tramadol and more common agents against this sort of pain are gabapentin, amitriptyline and pregabalin. Physical treatment agents such as transcutaneous electrical nerve stimulation may be used by attaching small electrodes to the skin and transmitting pain reducing signals to the central nervous system. Cognitive therapy may be necessary to help patients manage the problems of a long term pain.
Phantom pain can be an intractable, serious problem for anyone with an amputation, and having significant pain before the amputation may make the likelihood of phantom pain greater. A multidisciplinary approach involving a pain clinic is most likely to be helpful. - 14130
About the Author:
Jonathan Blood Smyth is a Superintendent Physiotherapist at an NHS hospital in the South-West of the UK. He specialises in orthopaedic conditions and looking after joint replacements as well as managing chronic pain. Visit the website he edits if you are looking for physiotherapists in London.
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