Phantom limb pain (PLP) is described as mild to extreme pain in an amputated limb. It was previously thought as a psychological response of patients who underwent amputation, but recent studies reveal scientific evidence of pain sensation that originates from the brain and spinal cord.
Although PLP is often seen in patients with amputated limbs, other individuals who underwent surgical removal of other body parts, such as eye, penis, and breast also complain of the pain sensation.
What Are The Causes Phantom Limb Pain?
Even if the limb is no longer present, the nerve endings found at the amputation site still sends signals to the brain. The brain then interprets the signal as coming from the limb, as if it is still there.
Before, PLP was thought to be a psychological response secondary to amputation but the increasing number of cases seen with PLP prompted medical experts to study the brain center for pain.
During positron emission tomography (PET) and magnetic resonance imaging (MRI), parts of the brain that have neural connections to the amputated limb showed activity when the patients is feeling phantom pain.
The experts concluded that PLP is the brain's response to mixed signals received after amputation and interprets it as pain.
It was also theorized that post-amputation, the brain automatically re-routes the sensory circuitry to another body part. This means that the brain processes the signal and sends the information to a non-existent limb or to a still-present cheek, for instance, that when the cheek is touched, it is felt as if the limb is still present and this result to PLP.
Does Phantom Pain Have Other Symptoms?
The pain may begin a few days post-surgery and may wax and wane over time.
Aside from the pain in the absent limb, many individuals report other symptoms such as cramping, tingling, and sensations of cold and heat in the amputated area.
Pain of PLP is often described as stabbing, shooting, boring, squeezing, or burning pain. Some report that emotional stress can trigger pain. Since brain memory of pain can also be present, other symptoms felt before amputation may also be present.
What Are The Available Treatments For Phantom Limb Pain?
Sensations of phantom limb pain may wax and wane over time, but complete cure may be difficult to achieve. Poor prognosis is seen in patients who have symptoms that last more than six months.
Treatment process is oftentimes dependent on the patient's level of pain tolerance and the combination of treatments.
Some patients benefit from heat application, relaxation techniques, local anesthesia injection, surgical removal of scar tissue, nerve blocking, transcutaneous electrical nerve stimulation (TENS), and spinal cord or deep brain stimulation.
According to a recent study, the use of minimally invasive cold blast treatments may also greatly reduce pain sensation. Cryoablation is done by inserting an image guided probe into the skin of the affected limb and blasting the nerves with cold temperature to shut it down and prevent the signals from reaching the brain. Cold blasting for 25 minutes afforded relief from pain.
The use of augmented reality was also found to be help amputees deal with PLP. Augmented reality uses mirror therapy wherein the amputee would face a mirror that reflects back an image that shows as if the remaining limb has taken the place of the amputated limb. The therapy is beneficial for patients who have lost only one leg.
In the U.S., there are about 2 million people who have lost their limbs secondary to vascular diseases (peripheral arterial disease and diabetes), trauma, and cancer. A nationwide field study found that 74.5 percent of amputees experience PLP, which greatly affects the quality of life.
Photo: U.S. Naval Force Central Command | Flickr
