Phantom Limb Pain
How does it work?
Phantom Limb Pain is a well-known post-surgical pain condition. After limb amputation, the pain can be either stump pain or phantom pain. In stump pain, patients often find this reduces as the operation site heals.
Phantom limb pain (PLP) affects a high proportion of amputees, between 50% and 85% of amputees. It may begin in the first few weeks after surgery. There is a high variability of the duration of the pain attacks, reported at anywhere between 1 hour and 15 hours a day and it can last for 5 days a month to 20 days.
It was once assumed that children or that people born without limbs do not get phantom limb pain. However, recent research has shown that pain after amputation arises in the brain itself which doesn’t mean that it is ‘all in your head and not real’ but it does mean that the treatments will need to be different to treatment aimed at relieving stump pain.
Recently, an APMA representative was speaking to a Senior Citizens Club on the topic of Pain Awareness and one gentleman, stood up and said he’d had phantom limb pain since 1996 and the doctor told him, “Look, there’s nothing there, the pain is all in your head.” Today, there should be a greater understanding that phantom limb pain (PLP) is very real, and yes, it is the brain that activates pain, i.e. no brain, no pain. Treatment is available and should be offered to amputees to reduce the pain and distress associated with PLP.
In Australia the main causes of amputation are: diabetes, trauma, vascular disease, cancer, infections and congenital differences www.limbs4life.com.au but in countries facing or recovering from war it is landmines which cause the most amputations. The incidence of PLP with amputees is very common.
What is Phantom Limb Pain (PLP)?
PLP is pain in the limb which is missing, and used to be considered a psychological challenge but neuroscientists now recognize that it is pain caused by the brain and spinal column. It can occur with the elimination of other body parts such as a breast or tongue.
Often PLP begins soon after the amputation and can be continuous or intermittent. The pain is generally felt in the furthest part of the amputated limb (feet, hands) and is often described as: stabbing, burning, squeezing or being crushed. It can vary in its intensity which may be slight to excruciating.
Damage to nerve endings occurs during trauma as well as from amputation, and, when nerve endings regrow they may lead to abnormal and painful firing of neurons in the stump, which may change the way that nerves from the amputated limb connect to neurons in the spinal cord and brain.
Cramping and squeezing PLP can also reflect muscle tension in the present limb. Changes in muscle tension in the remaining limb can precede changes in cramping and squeezing PLP.
It appears that pain has a ‘physical memory’ and that severe pain before the amputation can lead to severe PLP, because the brain holds onto the pain memory and continually floods the body with pain signals. This brain action occurs outside of the affected person‘s ability to consciously control the pain memory.
There is a map of ‘body parts’ inside the brain. This means that the brain retains the limb part in the brain even after the limb has been amputated. Magnetic resonance imaging (MRI) or brain imaging allows scientists to show the brain activity when a person feels PLP.
At the outset, it needs emphasizing that medical approaches would be multidisciplinary, acknowledging that effective pain has significant effect on the enjoyment of life, activities of daily living, work, family and one’s own psychological state.
Often the medical management of phantom limb pain, as with other persistent pain conditions, will begin with a team of therapists under the direction of a pain medicine specialist, appropriately assessing the patient. There may be a need for some ongoing support from a psychologist working with the team.
It is important for people with phantom limb pain to understand the mechanism of the pain and the central print of the pain on the brain.
Treatments relate to regular exercise, a satisfactory sleep routine and avoidance of stimulants such as cigarettes, chocolates and some medications while there should be some emphasis on community involvement and distractions.
Working hand in hand with these, the use of medications may be of complimentary value but as usual for persistent pain they fall short of hopes and expectations. Physiotherapy has an important part to play with the Graded Motor Imagery. There is not a lot of support for spinal cord stimulation in these cases.
Generally, doctors will ‘start low and go slow’ when prescribing medication for pain. There is no single form of treatment that claims complete success with PLP.
Paracetamol (with or without a weak opioid), and non-steroidal anti-inflammatory drugs (NSAIDs) may be effective, followed by more "centrally acting" medication like tricyclics or anticonvulsants, and strong opioids. Transcutaneous electrical nerve stimulation (TENS), may also work to interrupt the nerve signals travelling to the spinal cord.
Treatments that reduce muscle tension in the remaining limb can reduce cramping PLP. Amputees report that cramping PLP decreases during activities that lessen muscle tension in the residual limb, and increases with activities that increase tension. Phantom exercises that alter muscle tension in the residual limb can influence the intensity of phantom pain.
Graded Motor Imagery uses brain exercises which re-align the limb in the brain by using repetitive movements to retrain the brain that all is healed. The mirror therapy uses mirrors that make it look like the amputated limb exists, to trick the brain. The person then performs exercises, while watching the intact limb move and imagining that they are actually observing the amputated limb move. For a detailed explanation see http://www.gradedmotorimagery.com/index.htm
These new approaches are all based on a shift in emphasis in PLP away from the amputation site to the central nervous system. It appears that distorted feedback from the limb's nerves, coupled with exaggerated signals back to the limb result in PLP.
"I have lived this pain with ever since the amputations and it can indeed be debilitating and soul destroying.
"I sometimes try a head phone at night when the pain is over active. I find calming music played softly can help focus the mind away from the pain. I also find limb and body massage very soothing."
The Hon. Graham John Edwards AM
Vietnam War veteran, lost both legs from a landmine blast.
Former Federal MP & WA Government Minister