Phantom limb pain (i.e. “phantom pain”) is the sensation of the presence of an amputated or lost limb, along with the associated pain in the missing limb area. A person still feels that the limb is attached to the body, moving along with other parts of the body. Approximately 60% to 80% of the people with amputated limbs experience phantom sensations, and the majority of these sensations are painful. In many cases, phantom pains are intermittent and worsened by stress, anxiety, and weather changes. The pain experienced in the phantom limb is similar to the pain in the limb prior to amputation; the pre-amputation pain is the risk factor for the development of the phantom pain following amputation. Even the pain experienced in the limb months or years before amputation can be re-experienced. Chemotherapy drugs, especially which cause peripheral neurotoxicity, used to treat cancer before the amputation can be another risk factor for phantom pain. After the amputation, in some cases, there will be 50% to 70% decline in the prevalence of pain over the course of 2 years.
Phantom pain is the combination of more than one types of pain. These pains may consist of lancinating, cramping, and/or burning (among others). Other types of pain include pinching, stinging, sharp pins-and-needles sensation, itching, aching, crushing, and twisting. Typically pain occurs in the distal part of the phantom limb and pain distribution may not follow the path of the nerve served before amputation. The phantom pain is result of complex interactions between peripheral and central nervous system. During the amputation, serving of the peripheral nerves disrupts normal afferent nerve input in to the spinal cord, this process is called deafferentation. The deafferentation leads to degeneration of the distal portion of the peripheral nerves and proximal portion of peripheral nerves survive. These severed nerve endings are called as neuromas. Phantom pain is felt, if the neuromas get inflamed, and also they send anomalous signals to the brain which are functionally nonsense. These signals are interpreted by the brain as pain. According to a concept called “proprioceptive memory”, the brain retains a memory of specific limb positions and its sensation. Even after the amputation memory system of the brain remembers the limb as a functioning part of the body.
Some treatments for phantom pain include spinal cord stimulation, antidepressants, vibration therapy, acupuncture, hypnosis and biofeedback. In some patients spinal cord stimulation can be effective treatment. In this treatment an electric stimulator is implanted in the skin and an electrode is placed next to the spinal cord. The nerve pathways in the spinal cord are stimulated by an electric current which interferes with impulses traveling in the spinal cord towards the brain. This interference by spinal cord stimulation lessens the pain felt in the phantom limb.
As a drug-free, inexpensive, non-intrusive, non-pharmacological alternative, Farabloc™ is an effective therapy for phantom pain relief. Farabloc is an electromagnetic shielding fabric which can be wrapped around the amputated limb. This product blocks the high frequency electromagnetic field radiation while allowing low frequency electromagnetic fields to penetrate through. The low frequency electromagnetic field stabilizes cellular permeability and reduces release of anti-inflammatory factors causing decreased pain perception.
For more information on Farabloc and its’ benefits, please visit our “What is Farabloc?” page.