Novel Treatment Device for Phantom-Limb Pain
When a person loses a limb through a traumatic event, pain from the injury does not cease following amputation. Phantom limb pain occurs in as many as 85% of these individuals who undergo surgical amputation. Patients, at times, perceive the phantom limb as adopting a habitual position and posture; at other times, they perceive the limb as being in an abnormal position, with the entire limb or portions of it twisted out of shape, floating in space, or frozen in a fixed position. This can be extremely distressing for the patient and can cause feelings ranging from discomfort to severe pain.
It is not uncommon for a patient to feel sensations from a phantom limb all the time, but phantom limb pain often occurs intermittently several times a day. Pain felt prior to the amputation often is mimicked in the phantom limb, and the patient feels as if they are still experiencing the pain. The pain often is described as a burning, cramping, or shooting sensation that ranges from mild to severe. In addition to pain, patients feel specific sensations in the phantom limb such as touch, temperature (hot and cold), vibration, pressure, tingling, and itching.
Evolution of Phantom Limb Pain
The incidence of this chronic pain syndrome has been climbing due to injuries incurred during the Iraq and Afghanistan military conflicts. Until recently, the predominant theory for the cause of phantom limb pain was irritation in the severed nerve endings.1
When a limb is amputated, many severed nerve endings are terminated at the remaining stump. These nerve endings can become inflamed, and were thought to send anomalous signals to the brain. These signals, being functionally nonsense, were thought to be interpreted by the brain as pain.
In 1999, Melzak proposed that a pain neuromatrix is activated in specific brain regions, ultimately resulting in pain sensations independent of the sensory source of the pain.2 With a better understanding about how acute pain becomes chronic, it now is believed that phantom limb pain is a central pain phenomenon caused by remodeling of the central nervous system (CNS), starting at the affected limb and moving throughout the entire sensory pathway all the way up to the cortex.3 In other words, phantom pain may be a maladaptive failure of the neuromatrix to maintain global bodily constructs.4
Research now indicates that the pathophysiology comes from changes at the dorsal horn and higher levels in the CNS.5
Prophylactic measures are used to try to prevent phantom limb pain from developing for elective amputations (as in diabetic patients with chronic wounds, patients with osteomyelitis, etc). However, traumatic amputations do not permit prophylactic care.
Promising New Treatment
This case report describes the use of a promising and relatively new electric cell signaling treatment device for phantom limb pain. The device uses a digitally generated, non-invasive alternating signal current, delivered by a wave generator and administered transcutaneously.
The complex signal energy waveforms are formed first as electrically balanced, biphasic symmetrical sinusoidal primary waves, and then modulated by superimposed frequencies (Hz) and varying dosages (amplitude) to create complex rapidly changing signals that easily pass through dermal tissue and avoid repetitive nerve accommodation. These specific and time-varying pulsed electric signals are introduced through the skin of injured or diseased tissue by special vasopneumatic electrodes.
The administration of these complex electrical signals is accomplished by advanced electronic signal energy microprocessors, also known as microelectric mechanical systems (MEMS), which were not available a few years ago. The term we use to describe these bioactive electric energy signals when applied to a patient is electric cell signal treatment (EST).
The EST device is engineered and produced as a collaborative effort by Sanexas International GmbH (Germany); Resonant Specific Technologies, Inc. (USA); and Morhea Technologies LLC (USA), and uses an ultra-high digital frequency generator (UHdfg) system that can deliver targeted, combined frequency-modulated (FM) and amplitude-modulated (AM) electric energy signals transcutaneously into the body. The details regarding EST technology were first introduced, defined, and described in earlier published work by the authors.6
The electronic time-varying signals, associated harmonics, and resonance frequencies offer numerous physiologic advantages over older electromedicine devices, such as transcutaneous electrical nerve stimulation (TENS), powered muscle stimulators, microcurrent devices, high-voltage galvanic devices, or interferential current therapy. These advantages include enhancing circulation and local blood flow and increasing cyclic AMP (cAMP) levels necessary for cell healing.7 In addition, the device helps mitigate inflammation.7
Characteristics of Acute Inflammation
To better understand the latter process, one must first understand the characteristics of acute inflammation. Inflammation is characterized by:
- vasodilatation of local blood vessels, with consequent excess local blood flow
- increased permeability of capillaries, with leakage of large quantities of fluid into the interstitial spaces
- clotting of the fluid in the interstitial spaces because of excessive amounts of fibrinogen and other proteins leaking from capillaries
- migration of large numbers of granulocytes and monocytes into the tissue
- swelling of the tissue cells
The inflammatory response produces pain, redness, heat, and swelling.8
The intent of chemical interventions (ie, non-steroidal anti-inflammatory drugs) for the treatment of the inflammatory process is to block the process at one or more of the initial steps in the cascade. The authors postulate that EST energy can be used to facilitate the naturally occurring inflammatory process, without interfering with the normal inflammatory cascade progression, until inflammation is resolved.
This facilitation accelerates the anti-inflammatory process to reduce the probability that it becomes drawn out and leads to chronic inflammation. The specific mechanisms of action of the applied electronic signal energy can be used to reduce or modify the undesired symptoms normally present during this inflammation cascade (Figure 1).