‘Phantom’ Limb is a sensation that makes an amputee feel that the limb removed is still present. Also referred to as ‘stump hallucination’ this near-real experience is highly subjective and is not triggered by external stimulus.

S. Weir Mitchell’s first documented the phantom limbs while working with Civil War amputees at a Philadelphia hospital. He brought forth an account of his first hand experience with amputees, some of who were sure that they could still feel their amputated arms or legs. This generated a lot of curiosity in Mitchell’s days but today we know, only too well, that the sensation is far too common in the ‘land of the missing limbs’!

A study conducted by Vilayanur Ramachandran, who has done extensive work on phantom limbs using Q-Tips, revealed that certain areas of an amputated hand are mapped on different areas of the body. When the left side of the amputee’s chin is lightly brushed with a Q-tip, the person would report sensations in particular areas on the phantom limb.

This neuroscience expert believes that an existing, but hidden, neural circuitry linked to cortical remapping comes to life and is responsible for the phenomenon.

This sensation may often develop into a condition known as the Phantom Limb Pain (PLP). It is a condition, a serious one at that, which causes an amputee to experience chronic pain in the area where the amputed limb was once located. Victims have variously described the pain as aching, burning, or as though   the ‘hand is being crushed in a vice’. These descriptions may not explicitly convey the angst of the sufferer. However, it is a well-known fact that the pain has the potential to interfere with social life.

Our understanding of the phantom limb sensation is derived from limited case studies, as direct physical study is not possible. Here are some interesting facts about phantom sensations:

On an average, 80% of amputees experience phantom limb sensations.

• The sensation may be felt immediately after an amputation. In some, it is felt months or years later.
• The nature of the sensation varies from patient to patient.
• In many phantom limb sensations tend to occur after an injury at the amputation site.
• The use of Prosthetic devices help in the management of phantom sensation
• Phantom limb sensation is not typically experienced by infants and toddlers
• For phantom sensation, limbs need not be severed or amputated.
• It also occurs in peripheral nerve injuries or after spinal cord injuries.

Underlying Mechanisms

Several mechanisms are suggested that play an underlying role in generating phantom pain. It has been shown, by researchers, thatthe development of phantom limb pain has a lot to do with alterations in the way peripheral body regions are represented in the sensory cortex of the brain. In a phantom pain victim, a mismatch develops between the built-in map of the physical body within the brain and what it actually perceives.