Phantom limb
[1] When the cut ends of sensory fibres are stimulated during thigh movements, the patient feels as if the sensation is arising from the non-existent limb.
Research continues to explore the underlying mechanisms of phantom limb pain (PLP) and effective treatment options.
Specifically, there have been several reports from patients of painful clenching spasms in the phantom hand with the feeling of their nails digging into their palms.
The motor output is amplified due to the missing limb; therefore, the patient may experience the overflow of information as pain.
The patient contains repressed memories from previous motor commands of clenching the hand and sensory information from digging their nails into their palm.
[7] Despite the term "phantom limb" not being coined until 1871 by a physician named Silas Weir Mitchell, there have been earlier reports of the phenomenon.
[8] One of the first known medical descriptions of the phantom limb phenomenon was written by a French military surgeon, Ambroise Pare, in the sixteenth century.
[9] For many years, the dominant hypothesis for the cause of phantom limbs was irritation in the peripheral nervous system at the amputation site (neuroma).
[10] According to Melzack the experience of the body is created by a wide network of interconnecting neural structures, which he called the "neuromatrix".
[10] Pons and colleagues (1991) at the National Institutes of Health (NIH) showed that the primary somatosensory cortex in macaque monkeys undergoes substantial reorganization after the loss of sensory input.
Later brain scans of amputees showed the same kind of cortical reorganization that Pons had observed in monkeys.
[14] Despite a great deal of research on the underlying neural mechanisms of phantom limb pain there is still no clear consensus as to its cause.
Kinetic phantom sensations are perceived movements of the amputated body part (i.e., feeling your toes flex).
In phantom limb syndrome, there is sensory input indicating pain from a part of the body that is no longer existent.
Central sensitization is when there are changes in the responsiveness of the neurons in the dorsal horn of the spinal cord, which deals with processing somatosensory information, due to increased activity from the peripheral nociceptors.
Treatment approaches have included medication such as antidepressants, spinal cord stimulation, vibration therapy, acupuncture, hypnosis, and biofeedback.
[23] Perineural catheters that provide local anesthetic agents have poor evidence of success when placed after surgery in an effort to prevent phantom limb pain.
