A phantom is something that doesn’t actually exist, an imagination or an apparition. But for Otto K., 62, the so-called phantom pain in his amputated lower right leg is more than real: “Some days the pain is as sharp as if I were being attacked with a knife. Other days, it tingles and itches in my foot and other places that aren’t even there anymore.”
Phantom limb pain in one in two amputees
About 60,000 amputations are performed in Germany each year, 70 percent of which are for diabetics – Otto K. also lost his lower leg because of a non-healing ulcer. He suffered from diabetic foot syndrome, which usually develops as a result of chronically poorly controlled blood sugar, causing long-term damage to the nerve endings. He no longer felt pressure points or injuries, and only noticed wounds very late, when they no longer healed. In Germany, up to 27,000 foot amputations are performed annually on people with diabetes. More than two-thirds of all amputations are caused by arterial circulatory disorders. The number of people with vascular disease in Germany is estimated at four to six million. Seen in this light, the risk potential is far higher than initially assumed. Accidents cause four percent of all amputations. The proportion of amputations caused by infections and tumors is about the same. And about every second person affected suffers – often for years. In some cases, the pain is constant, but more often it occurs suddenly. Weather changes, but also stress or stimulants such as coffee can be the triggers.
Pain in the stump
Stump pain, unlike phantom limb pain, is precisely localized to the area of the amputation stump. It can occur spontaneously or after fitting a prosthesis in nearly 60 percent of all amputations. Patients describe this pain as burning, electrifying, cutting, stabbing or cramping. It is almost always a continuous pain that can be attributed to disturbances in wound healing. Pressure points caused by an ill-fitting prosthesis, inflammations such as pus accumulations under the skin (abscesses) or bone marrow inflammations can also be the cause, and in some cases circulatory disturbances in the stump. What often happens after severing a limb: At the outer end of a severed nerve, so-called neuromas develop, which are benign nodule formations. They are sensitive and react to stimulation of any kind with great pain. Even a normal touch can cause the severe pain.
Pain remains in the memory
The majority of all women and men with amputations suffer from phantom limb pain. This involves pain in the affected person’s extremities, which are no longer present. It is thought that the brain continues to receive pain signals from the nerves that were once responsible for that part of the body. Phantom limb pain is also felt in other parts of the body in some patients, such as after breast removal, rectal surgery, or tooth extraction (especially wisdom teeth). Often the pain is more severe at night than during the day. It is also typical that the phantom pain resembles the pain before the amputation. The culprit is pain memory: with every injury or inflammation, pain receptors send electrical impulses to the spinal cord. From there, the nerve signals are transmitted to the brain. This is where the sensation of pain arises. If the stimulus is strong and long-lasting, the pain can take on a life of its own. A pain memory develops that is difficult to erase. For example, the severe pain before or during an amputation can very often leave traces in the spinal cord and brain. For this reason, patients today often receive what is known as a cross-stitch, or spinal anesthesia, before amputations, which numbs the nerves in the spinal cord to prevent hypersensitivity of the spinal cord.
Pain management with medications
When treating phantom limb pain, a variety of options often must be tried until adequate pain relief is achieved. Common pain therapies include opiates, such as morphine and related medications, for severe pain attacks. These medications are not over-the-counter like the common pain medications (acetylsalicylic acid, ibuprofen). Continuous therapy for continuous or frequent pain could be done with different medications.It is important that the medication is prescribed by the physician after a thorough anamnesis and possibly in cooperation with an outpatient pain clinic. Sometimes painkillers are combined with antidepressants, anti-epilepsy drugs or agents that specifically target the nerves. They raise the nerve cells’ threshold for pain signals. The hormone calcitonin has also been shown in studies to counteract phantom limb pain. It is a thyroid hormone, a peptide of 32 amino acids, and can slow bone loss in osteoporosis by counteracting the release of calcium from the bones and lowering the calcium level in the blood. Physical procedures such as electrical stimulation (TENS) are used as a supplement: Weak electrical stimuli transmitted to the amputation stump with electrodes stimulate new connections between nerve cells in the brain. These “overwrite” the old, painful impressions. Some patients, however, swear by non-stimulation and wear a special residual limb cover designed to shield electrical stimuli. Baths, massage and physical therapy are useful in many cases, but should be tailored to individual patient needs and preferences. Acupuncture can help relieve pain. Those who lose a body part should, medical professionals agree, receive psychological support to cope with the loss, as well as behavioral therapy. This is another way of dealing with the pain. But the fact is: to date, there is no single therapeutic approach, although there are some new and promising options.
Mirror Therapy
It sounds a bit like hocus-pocus, how some physicians, therapists and patients want to outsmart phantom pain: This is because a cleverly placed mirror makes it look to the patient as if the reflection of the healthy limb is the amputated limb. It is this visual impression that awakens a memory in the brain of the missing arm or leg. It stops substituting pain for the input signals that are no longer present from the nerves of the affected limb. The method also works for stroke patients suffering from paralysis or perceptual disorders. Prof. Dr. Christoph Maier and occupational therapist Susanne Glaudo have developed two training devices that facilitate practice in front of a mirror and can also be used at home. Once again, it is the brain that creates sensations, because there is a kind of image of the whole body there in which the sensations from the respective body parts are processed. If the signals from the amputated arm or leg are missing, certain centers in the brain replace this missing information with pain, explains Susanne Glaudo. The effect can even be intensified if the patient does dexterity exercises with the healthy hand, which he only looks at in the mirror, or looks at the hand or leg in the mirror, while sensory impressions are evoked, for example, by touching it with a brush or a hedgehog ball.
Prostheses
There is even evidence that a prosthesis helps prevent phantom limb pain. The reason: to move the artificial leg, the patient must activate thigh muscles. The brain registers these movements and gets the impression that the leg is intact. This is why phantom limb pain can even be reduced by regularly wearing an optimally fitted prosthesis. In some amputees with phantom limb pain, it improves on its own and sometimes even disappears completely. However, the course cannot be predicted.
