As hard as it is to believe, people can experience pain in a part of the body that was amputated or removed. Phantom limb pain is not a figment of the person’s imagination, nor is it psychosomatic. Phantom pain is real, say experts.
“It is the perception of pain or discomfort in a limb that no longer exists,” says Dr Pavan Chebbi, a senior consultant orthopedic surgeon at Apollo Spectra Hospitals, Koramangala, Bengaluru.
It is experienced by around 80 per cent of amputees.
“The condition, phantom limb pain syndrome, was widely seen in the soldiers of the world wars whose limbs were lost in war,” says Dr Rahul Chakor, neurologist, Saifee Hospital, Mumbai. “The individual feels as if the missing limb is still attached to the body and perceives intense pain in the limb. Though the limb is missing, the pain is real and quite distressing to the individual.”
What causes phantom limb pain?
Over the years, incidences of phantom limb pain have increased. The exact cause or the mechanism of phantom pain is still unclear. It was initially considered to be a psychiatric illness until the role of the nervous system in phantom pain perception was discovered.
“The origin of the pain is in the nervous system. The residual damaged nerves, spinal cord, thalamus and cortex could be sites for the pain origin,” says Dr Chakor.
During amputation, the peripheral nerves get severed and the nerve endings of these peripheral nerves are then rewired.
“The nerve endings also sprout to form neuroma (benign tumor) and the neurons become hyperexcitable [sensitivity increases],” says Dr Chebbi. “This leads to alteration of the pain perception process in the spinal cord. In the brain, the part of the cortex that represents the amputated area is taken over by the neighbouring region. Thus, the individual perceives the pain in the part of the limb that has been amputated.”
Other factors, such as stress, anxiety and depression are known to intensify the pain.
Diagnosis of phantom limb pain
One can easily get confused between phantom limb pain, residual limb pain and phantom limb sensation. Residual limb pain is the pain perceived in the remaining part of the amputated limb, whereas phantom pain sensations are non-painful sensations in the amputated limb.
“The phantom limb pain can be cramping, pins and needles, throbbing, electric shock-like, deep intense pain that is distressful,” says Dr Chakor. “The severity of pain can vary.”
Pain is intermittent mostly.
“Phantom pain may be felt for a few seconds, minutes, last for a few hours or even be permanent,” adds Dr Chebbi. “Usually within the six months following amputation, the pain frequency begins to reduce. But some individuals feel the pain for years.”
It is usually diagnosed on the principle of exclusion, where it is differentiated from other types of pain like limb pain/stump pain which might also co-exist or pain caused due to some sort of infection in the amputated region.
Treatment methods
Treatment includes both pharmacological and non-pharmacological methods.
“Pharmacotherapy with analgesics, opioids, antidepressants and anticonvulsants which are commonly used for neurogenic pain have been tried with variable success,” says Dr Chakor. He adds that transcutaneous electrical nerve stimulation (using low voltage electric current to treat pain) and sympathetic ganglion blocks (a medication injected to numb the nerve and stop the pain signals that are being sent to the brain) are also effective.
Mirror therapy is one of the commonly used non-pharmacological methods that yield satisfactory results.
“In mirror therapy, we use a mirror that reflects the existing limb and tricks the brain into thinking that the reflection is the amputated limb,” says Dr Chebbi. “This makes the brain think that the movement has occurred without pain. It creates positive visual feedback of limb movement, thus helping the brain to overcome the pain in the amputated limb.”
Phantom pain syndrome not only occurs in limbs but also other parts of the body like the eyes, ears, breasts (following mastectomy) or tooth (following an extraction.)
Takeaways
- Phantom limb pain syndrome is a condition in which the individual experiences pain in a limb that was amputated and doesn’t exist.
- During amputation, the nerve endings close to the limb being amputated get severed. Re-wiring of these nerve endings can cause phantom limb pain.
- Treatment of phantom pain includes both pharmacological and non-pharmacological methods.
- Phantom pain syndrome is seen even in other parts of the body like the eyes, ears, breasts (following mastectomy) or tooth (following an extraction).