Phantom Limbs

After many weeks of deciding the theme of my blog, i have decided to choose neuroscience after watching a talk by V.S Ramachandran. Neuroscience is the indepth study of the brain and nervous system.

More information about phantom limbs can be found at http://brain.oxfordjournals.org/content/121/9/1603.full.pdf

Phantom limbs occur after a limb is amputated or loss due to an incident and the victim feels the sensation of the limb still been there. After the immediate loss of a limb, its found that between 90% and 98% experience a phantom limb. In 1948, Moser found that when the anaesthetic wore off on the patients and the patient was conscious, 75% felt the immediate phantom but the appearance in the remaining 25% of cases did not exist until a few days or weeks after the incident.

In most cases the phantom exists for a few days or weeks but in others it may persist for years or decades. Long term duration can be found in up to 30% of the patients who suffer the phantom limb according to Sunderland (1978)

V.S Ramachandran(2007) has reported that 50% of his patients that have phantom limbs say that they have the feeling they can move the phantom by doing such things as answering a telephone, pat the dog etc. The patients are not delusional as they are aware that the arm/leg is no longer there but it is a vivid sensory sensation for the patient. For the other half of patients, they cannot move it. They report the phantom limb as been in a paralyzed state, in a “clenched spasm” and is very painful. Ramachandran found that in the case studies of those patients the original arm was paralyzed due to peripheral nerve injury of the arm as the nerves were severed or cut due to the incident. The arm, in a paralyzed state, is put in a sling for several months then amputated and the pain the patient experience before continues onto the phantomb limb. This state of paralisis occurs when the arm is intact but paralyzed and the brain sends signals and commands to the arm telling it to move but on visual feedback to the brain it sees it can’t move and on repetition of the command and feedback, the brain goes into a state of learnt paralysis which then follows onto the phantom arm.

The continuous pain of the phantom arm/leg can have many effects of the victim such as depression and has even been known to lead people to suicide. V.S Ramachandran (2007) researched the effects of phantoms and his findings have led to a solution for many sufferers. He uses what he calles the “mirror box” which is a mirror seperated by cardboard then another mirror following. The patient puts the stump arm close to first mirror at a 90 degree angle and the other arm in the same position and asks the patient to move the hand of the phantom arm and the able arm. The mirror reflects the able arm to represent the phantom arm actually exists which sends the visual feedback to the brain to give the brain the impression its there and can move so it releases the phantom from paralyzed state and the patient is relieved from pain.

http://www.youtube.com/watch?v=Rl2LwnaUA-k from 9.00

The simplicity of the solution is to be admired and mirror therapy is been used as a result of this research to help sufferers of phantom limbs.