Electroanalgesia

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Electroanalgesia is a form of analgesia, or pain relief, that uses electricity to ease pain. Electrical devices can be internal or external, at the site of pain (local) or delocalized throughout the whole body. It works by interfering with the electric currents of pain signals, inhibiting them from reaching the brain and inducing a response; different from traditional analgesics, such as opiates which mimic natural endorphins and NSAIDs (non-steroidal anti-inflammatory drugs) that help relieve inflammation and stop pain at the source. Electroanalgesia has a lower addictive potential and poses less health threats to the general public, but can cause serious health problems, even death, in people with other electrical devices such as pacemakers or internal hearing aids, or with heart problems.

Contents

History

The first cases of electroanalgesia were documented by Greek scholars, Plutarch and Socrates, who noticed numbing effects of standing in pools of water on a beach that contained electric fish (icthyoelectroanalgesia). [1] The Chinese practice of acupuncture, dating back to 3000 BCE, also utilizes the properties of electroanalgesia by stimulating specific nerves to produce electrical signals which produce pleasurable responses in the brain. [2] Another ancient analgesic method, aging back to 5000 BCE in Sumer, is to use natural minerals, vitamins, and herbs, usually in a mixture with other natural products. Technology invented specifically for electroanalgesia emerged at the beginning of the 1900s.

Technology

Advancements in technology within the past fifteen years have created multiple forms of electroanalgesia. Doctors can target specific electrical signals caused by pain and cancel them out using electrical signals, optimally with alternating low and high frequencies.

Transcranial electrostimulation

A theoretical explanation for the mechanism of pain reduction by transcranial electrostimulation, or TCES, suggests that the electrical stimulation activates the anti-nociceptive system in the brain, resulting in β-endorphin, serotonin and noradrenaline release. [3] TCES can be used on people with cervical pain, chronic lower back syndrome, or migraines. [3] It cannot be used on people with orthopedic or radiological potentially serious spinal conditions, hydrocephalus, epilepsy, glaucoma, malignant hypertension, pacemaker or other implanted electronic device; recent cerebral trauma, nervous system infection, skin lesions at sites of electrode placement; oncological disease; patients undergoing any other treatments for pain; any invasive therapy, e.g. surgery, within the last month. [3] The equipment used is Pulse Mazor Instruments' Pulsatilla 1000, which consists of a headset with three electrodes, two that go behind the ears and one that goes on the forehead, that release set frequencies of electricity at set intervals.

Deep brain stimulation

Deep brain stimulation, or DBS, was first evaluated as an electroanalgesic in the late 1950s. It works in some chronic pain patients. The mechanism of DBS is unknown. There is some evidence that it decreases pain transmission along sensory discriminative pathways although more recent studies have shown that it has central effects on other brain regions involved in the pain network (Pereira et al. 2007). [4] This method has mainly been used for chronic pain patients after all other options have failed due to potential of intracranial complications (e.g., intracranial hemorrhage, infection, and oculomotor abnormalities). An electrode is "stereotactically" guided to the site using magnetic resonance imaging and once in place, the electrode is activated by subcutaneous leads attached to a pulse generator under the skin. It is effective in treating refractory post-stroke pain, atypical face pain, anaesthesia dolorosa, and deafferentation and somatic pain such as in phantom limb or brachial plexus injury (Boccard et al. 2013). [5]

Peripheral nerve stimulation

The use of peripheral nerve stimulation, or PNS, for the relief of chronic pain states was first reported over 30 years ago. [6] Recent studies have demonstrated that electrical stimulation of nerves leads to inhibitory input to the pain pathways at the spinal cord level. [7] PNS is most effective in the treatment of neuropathic pain (e.g., posttraumatic neuropathy, diabetic neuropathy) when the nerve lesion is distal to the site of stimulation. [8]

Percutaneous electrical nerve stimulation

Percutaneous electrical nerve stimulation, or PENS, is used mainly in the treatment of intractable pain associated with chronic low back pain syndrome, cancer, and other disorders. [8] It is a technique involving insertion of an ultra-fine acupuncture needle which probes into the soft tissues or muscles to electrically stimulate nerve fibers in the sclerotomal, myotomal, or dermatomal distribution corresponding to the patient's pain symptoms. PENS is related to both electroacupuncture and transcutaneous electrical nerve stimulation. [8]

Percutaneous neuromodulation therapy

PENS used to be a term to describe a neurosurgical procedure involving implantation of temporary stimulating electrodes before an SCS device. [9] The term has recently been changed to percutaneous neuromodulation therapy, or PNT. The term PNT was chosen because it more accurately describes the neurophysiologic basis for PENS-induced analgesia.

Transcutaneous electrical nerve stimulation

Transcutaneous electrical nerve stimulation, or TENS, involves the transmission of electrical energy from an external stimulator to the peripheral nervous system via cutaneously placed conductive gel pads. TENS can be subclassified into two variants:

The purported mechanism of action of TENS invokes both spinal supraspinal theories. [8]

Transcutaneous acupoint electrical stimulation

Transcutaneous acupoint electrical stimulation, or TAES, is a variant of TENS therapy that involves applying cutaneous electrodes at classical Chinese acupoints and stimulating with alternating high- and low-frequency electric current ("dense-disperse"). [11] Acupoint stimulation is as effective as dermatomal stimulation in producing an analgesic-sparing effect after lower abdominal surgery [12]

H-wave therapy

H-wave therapy (HWT) is a form of electrical stimulation that produces a direct, localized effect on the conduction of underlying nerves. [13] The electrical stimulation used in HWT differs from other forms of electrical stimulation such as TENS in terms of its waveform; it is intended to emulate the H waveform found in nerve signals, thus permitting the machine to use less power while attaining greater and deeper penetration of its low-frequency current. The waves used in HWT are distinct from the H-waves that are part of electromyography. It has been used in the treatment of pain related to diabetic neuropathy, muscle sprains, temporomandibular joint disorders, type I complex regional pain syndrome as well as the healing of wounds such as diabetic ulcers. [14] [15] This electroanalgesic modality was originally recommended as an alternative to TENS for dental analgesia. In a 1999 randomized controlled trial involving a mechanical pain model, the analgesic effects of HWT were found to be short-lasting and identical to those provided by TENS therapy. [16] HWT has not been shown effective in reducing pain in cases other than diabetic neuropathy, nor has it been shown effective in reducing edema or swelling, and it has specifically not been shown effective in treating chronic pain due to ischemia. [15]

Interferential current therapy

Interferential current therapy, or ICT, is another variant of TENS that uses the principle of amplitude modulation to decrease the discomfort of stimulating deeper tissues (e.g., muscle) when using transcutaneously applied electric current. [17] A combination of different stimulation frequencies are used (i.e., one fixed at 4 kHz and another within a variable range) to generate frequencies between 4 and 250 Hz which are alleged to more effectively penetrate the soft tissues while producing less discomfort at the skin surface. [18] With ICT, its postulated mechanism of analgesic action is through direct stimulation of muscle fibers rather than nerves, allegedly improving muscle blood flow and promoting the healing process. Although ICT is used widely in the physiotherapy and rehabilitative medicine settings, there is a dearth of rigorously controlled studies to justify its effectiveness in the management of either acute or chronic pain syndromes. [8]

Piezo-electric current therapy

Piezo-electric current therapy, or PECT, is an analgesic technique based on the principle that mechanical deformation of a motorized piezoelectric ceramic rod produces a burst of 10 electrical pulses (five positive and five negative), each lasting 2–3 ms. Each electrical burst lasts for 50 to 250 ms (depending on the motor speed set) and generates a current of approximately 25 mA. The application of PECT to the skin for 2 min produces a tolerable "pricking" pain sensation associated with a neurogenic inflammatory response lasting 3–4 h. [8] The extent and duration of this inhibitory process is directly related to the intensity of the applied stimulus and is alleged to be associated with the release of endogenous endorphins. [19]

Controversies

Electroanalgesia poses serious health problems in those patients who need other electrical equipment in their bodies, such as pacemakers and hearing aids, because the electrical signals of the multiple devices can interfere with each other and fail. People with heart problems, such as irregular heartbeat, are also at risk because the devices can throw off the normal electrical signal of the heart.

See also

Related Research Articles

Local anesthesia is any technique to induce the absence of sensation in a specific part of the body, generally for the aim of inducing local analgesia, that is, local insensitivity to pain, although other local senses may be affected as well. It allows patients to undergo surgical and dental procedures with reduced pain and distress. In many situations, such as cesarean section, it is safer and therefore superior to general anesthesia.

<span class="mw-page-title-main">Pain management</span> Interdisciplinary approach for easing pain

Pain management is an aspect of medicine and health care involving relief of pain in various dimensions, from acute and simple to chronic and challenging. Most physicians and other health professionals provide some pain control in the normal course of their practice, and for the more complex instances of pain, they also call on additional help from a specific medical specialty devoted to pain, which is called pain medicine.

Diabetic neuropathy is various types of nerve damage associated with diabetes mellitus. Symptoms depend on the site of nerve damage and can include motor changes such as weakness; sensory symptoms such as numbness, tingling, or pain; or autonomic changes such as urinary symptoms. These changes are thought to result from microvascular injury involving small blood vessels that supply nerves. Relatively common conditions which may be associated with diabetic neuropathy include distal symmetric polyneuropathy; third, fourth, or sixth cranial nerve palsy; mononeuropathy; mononeuropathy multiplex; diabetic amyotrophy; and autonomic neuropathy.

<span class="mw-page-title-main">Peripheral neuropathy</span> Nervous system disease affecting nerves beyond the brain and spinal cord

Peripheral neuropathy, often shortened to neuropathy, is a general term describing disease affecting the peripheral nerves, meaning nerves beyond the brain and spinal cord. Damage to peripheral nerves may impair sensation, movement, gland, or organ function depending on which nerves are affected; in other words, neuropathy affecting motor, sensory, or autonomic nerves result in different symptoms. More than one type of nerve may be affected simultaneously. Peripheral neuropathy may be acute or chronic, and may be reversible or permanent.

<span class="mw-page-title-main">Transcutaneous electrical nerve stimulation</span> Therapeutic technique

Transcutaneous electrical nerve stimulation is the use of electric current produced by a device to stimulate the nerves for therapeutic purposes. TENS, by definition, covers the complete range of transcutaneously applied currents used for nerve excitation although the term is often used with a more restrictive intent, namely to describe the kind of pulses produced by portable stimulators used to reduce pain. The unit is usually connected to the skin using two or more electrodes which are typically conductive gel pads. A typical battery-operated TENS unit is able to modulate pulse width, frequency, and intensity. Generally, TENS is applied at high frequency (>50 Hz) with an intensity below motor contraction or low frequency (<10 Hz) with an intensity that produces motor contraction. More recently, many TENS units use a mixed frequency mode which alleviates tolerance to repeated use. Intensity of stimulation should be strong but comfortable with greater intensities, regardless of frequency, producing the greatest analgesia. While the use of TENS has proved effective in clinical studies, there is controversy over which conditions the device should be used to treat.

A microcurrent electrical neuromuscular stimulator or MENS is a device used to send weak electrical signals into the body. Such devices apply extremely small microamp [uA] electrical currents to the tissues using electrodes placed on the skin. One microampere [uA] is 1 millionth of an ampere and the uses of MENS are distinct from those of "TENS" which runs at one milliamp [mA] or one thousandth of an amp.

<span class="mw-page-title-main">Functional electrical stimulation</span> Technique that uses low-energy electrical pulses

Functional electrical stimulation (FES) is a technique that uses low-energy electrical pulses to artificially generate body movements in individuals who have been paralyzed due to injury to the central nervous system. More specifically, FES can be used to generate muscle contraction in otherwise paralyzed limbs to produce functions such as grasping, walking, bladder voiding and standing. This technology was originally used to develop neuroprostheses that were implemented to permanently substitute impaired functions in individuals with spinal cord injury (SCI), head injury, stroke and other neurological disorders. In other words, a person would use the device each time he or she wanted to generate a desired function. FES is sometimes also referred to as neuromuscular electrical stimulation (NMES).

Neuropathic pain is pain caused by damage or disease affecting the somatosensory system. Neuropathic pain may be associated with abnormal sensations called dysesthesia or pain from normally non-painful stimuli (allodynia). It may have continuous and/or episodic (paroxysmal) components. The latter resemble stabbings or electric shocks. Common qualities include burning or coldness, "pins and needles" sensations, numbness and itching.

<span class="mw-page-title-main">Alcoholic polyneuropathy</span> Medical condition

Alcoholic polyneuropathy is a neurological disorder in which peripheral nerves throughout the body malfunction simultaneously. It is defined by axonal degeneration in neurons of both the sensory and motor systems and initially occurs at the distal ends of the longest axons in the body. This nerve damage causes an individual to experience pain and motor weakness, first in the feet and hands and then progressing centrally. Alcoholic polyneuropathy is caused primarily by chronic alcoholism; however, vitamin deficiencies are also known to contribute to its development. This disease typically occurs in chronic alcoholics who have some sort of nutritional deficiency. Treatment may involve nutritional supplementation, pain management, and abstaining from alcohol.

Neuroprosthetics is a discipline related to neuroscience and biomedical engineering concerned with developing neural prostheses. They are sometimes contrasted with a brain–computer interface, which connects the brain to a computer rather than a device meant to replace missing biological functionality.

<span class="mw-page-title-main">Nerve conduction velocity</span> Speed at which an electrochemical impulse propagates down a neural pathway

In neuroscience, nerve conduction velocity (CV) is an important aspect of nerve conduction studies. It is the speed at which an electrochemical impulse propagates down a neural pathway. Conduction velocities are affected by a wide array of factors, which include; age, sex, and various medical conditions. Studies allow for better diagnoses of various neuropathies, especially demyelinating diseases as these conditions result in reduced or non-existent conduction velocities.

<span class="mw-page-title-main">Spinal cord stimulator</span> SCS TREATMENT

A spinal cord stimulator (SCS) or dorsal column stimulator (DCS) is a type of implantable neuromodulation device that is used to send electrical signals to select areas of the spinal cord for the treatment of certain pain conditions. SCS is a consideration for people who have a pain condition that has not responded to more conservative therapy. There are also spinal cord stimulators under research and development that could enable patients with spinal cord injury to walk again via epidural electrical stimulation (EES).

Dysesthesia is an unpleasant, abnormal sense of touch. Its etymology comes from the Greek word "dys," meaning "bad," and "aesthesis," which means "sensation". It often presents as pain but may also present as an inappropriate, but not discomforting, sensation. It is caused by lesions of the nervous system, peripheral or central, and it involves sensations, whether spontaneous or evoked, such as burning, wetness, itching, electric shock, and pins and needles. Dysesthesia can include sensations in any bodily tissue, including most often the mouth, scalp, skin, or legs.

Sacral nerve stimulation, also termed sacral neuromodulation, is a type of medical electrical stimulation therapy.

Clinical electrophysiology is the application of electrophysiology principles to medicine. The two main branches of this discipline are electrotherapy and electrophysiologic testing Clinical electrophysiology can be utilized in the study and treatment of various physiological conditions, and most notably in clinical cardiac electrophysiology.

Neurostimulation is the purposeful modulation of the nervous system's activity using invasive or non-invasive means. Neurostimulation usually refers to the electromagnetic approaches to neuromodulation.

Pain in cancer may arise from a tumor compressing or infiltrating nearby body parts; from treatments and diagnostic procedures; or from skin, nerve and other changes caused by a hormone imbalance or immune response. Most chronic (long-lasting) pain is caused by the illness and most acute (short-term) pain is caused by treatment or diagnostic procedures. However, radiotherapy, surgery and chemotherapy may produce painful conditions that persist long after treatment has ended.

Interventional pain management or interventional pain medicine is a medical subspecialty defined by the National Uniforms Claims Committee (NUCC) as, " invasive interventions such as the discipline of medicine devoted to the diagnosis and treatment of pain related disorders principally with the application of interventional techniques in managing sub acute, chronic, persistent, and intractable pain, independently or in conjunction with other modalities of treatment". Medicare Payment Advisory Commission (MedPAC) defined interventional techniques as, "minimally invasive procedures including, percutaneous precision needle placement, with placement of drugs in targeted areas or ablation of targeted nerves; and some surgical techniques such as laser or endoscopic diskectomy, intrathecal infusion pumps and spinal cord stimulators, for the diagnosis and management of chronic, persistent or intractable pain". Minimally invasive interventions such as facet joint injections, nerve blocks, neuroaugmentation, vertebroplasty, kyphoplasty, nucleoplasty, endoscopic discectomy, and implantable drug delivery systems are utilized in managing subacute or chronic pain.

Neuromodulation is "the alteration of nerve activity through targeted delivery of a stimulus, such as electrical stimulation or chemical agents, to specific neurological sites in the body". It is carried out to normalize – or modulate – nervous tissue function. Neuromodulation is an evolving therapy that can involve a range of electromagnetic stimuli such as a magnetic field (rTMS), an electric current, or a drug instilled directly in the subdural space. Emerging applications involve targeted introduction of genes or gene regulators and light (optogenetics), and by 2014, these had been at minimum demonstrated in mammalian models, or first-in-human data had been acquired. The most clinical experience has been with electrical stimulation.

Peripheral mononeuropathy is a nerve related disease where a single nerve, that is used to transport messages from the brain to the peripheral body, is diseased or damaged. Peripheral neuropathy is a general term that indicates any disorder of the peripheral nervous system. The name of the disorder itself can be broken down in order to understand this better; peripheral: in regard to peripheral neuropathy, refers to outside of the brain and spinal cord; neuro: means nerve related; -pathy; means disease. Peripheral mononeuropathy is a disorder that links to Peripheral Neuropathy, as it only effects a single peripheral nerve rather than several damaged or diseased nerves throughout the body. Healthy peripheral nerves are able to “carry messages from the brain and spinal cord to muscles, organs, and other body tissues”.

References

  1. ↑ [Jensen, Jack E., Richard R. Conn, Gary Hazelrigg, and John E. Hewett. "The Use of Transcutaneous Neural Stimulation and Isokinetic Testing in Arthroscopic Knee Surgery." The American Journal of Sports Medicine 13 (1985): 27-33].
  2. ↑ [White, Paul F. "Electroanalgesia: Does it have a place in the routine management of acute and chronic pain?" Anesthesia and Analgesia 98 (2004): 1197-198.].
  3. 1 2 3 [Gabis L, Shklar B, Geva D: Immediate influence of transcranial electrostimulation on pain and β-endorphin blood levels: An active placebo-controlled study. Am J Phys Med Rehabil 2003;82:81-85.].
  4. ↑ [Pereira EA, Green AL, Bradley KM, Soper N, Moir L, Stein JF, Aziz TZ. Regional Cerebral Perfusion Differences between Periventricular Grey, Thalamic and Dual Target Deep Brain Stimulation for Chronic Neuropathic Pain. Stereotact Funct Neurosurg 2007 Mar 27;85(4):175-183 .].
  5. ↑ [Boccard SG, Pereira EA, Moir L, Aziz TZ, Green AL.Long-term Outcomes of Deep Brain Stimulation for Neuropathic Pain. Neurosurgery 2013;72(2):221-31 .].
  6. ↑ [Wall PD, Sweet WH. Temporary abolition of pain in man. Science 1967;155:108 –9.].
  7. ↑ [Hanai F. Effect of electrical stimulation of peripheral nerves on neuropathic pain. Spine 2000;25:1886 –92.].
  8. 1 2 3 4 5 6 [White, Paul F., Shitong Li, and Jen W. Chiu. "Electroanalgeia: Its Role in Acute and Chronic Pain Management." Anestesia and Analgesia 92 (2001): 505-13.].
  9. ↑ [North RB, Fischell TA, Long DM. Chronic stimulation via percutaneously inserted epidural electrodes. Neurosurgery 1977;1: 215–8.].
  10. ↑ [Han JS, Chen XH, Sun SL, et al. Effect of low- and high-frequency TENS on Met-enkephalin-Arg-Phe and dynorphin A immunoreactivity in human lumbar CSF. Pain 1991;47:295– 8.].
  11. ↑ [Wang BG, Tang J, White PF, et al. Effect of the intensity of transcutaneous acupoint electrical stimulation on the postoperative analgesic requirement. Anesth Analg 1997;85:406 –13.].
  12. ↑ [Chen L, Tang J, White PF, et al. The effect of location of transcutaneous electrical nerve stimulation on postoperative opioid analgesic requirement: acupoint versus nonacupoint stimulation. Anesth Analg 1998;87:1129 –34.].
  13. ↑ McDowell, Brona C.; Andrea S. Lowe; Deirdre M. Walsh; G. David Baxter; Jim M. Allen (September 1996). "The effect of H-wave therapy upon conduction in the human superficial radial nerve in vivo" (PDF). Experimental Physiology . New York City: Cambridge University Press. 81 (5): 821–832. doi: 10.1113/expphysiol.1996.sp003979 . ISSN   0958-0670. OCLC   20954666. PMID   8889480. S2CID   28503406.
  14. ↑ "H-Wave Stimulation" (PDF). Medical Policy Manual. The Regence Group. 2014-02-01. Retrieved 2014-02-22.
  15. 1 2 "Clinical Policy Bulletin: Electrical Stimulation for Pain". Aetna. 2009-03-04. Retrieved 2009-06-02.
  16. ↑ McDowell, Brona C.; Kenneth McCormack; Deirdre M. Walsh; David G. Baxter; Jim M. Allen (September 1999). "Comparative analgesic effects of H-wave therapy and transcutaneous electrical nerve stimulation on pain threshold in humans". Archives of Physical Medicine and Rehabilitation . W. B. Saunders. 80 (9): 1001–1004. doi:10.1016/S0003-9993(99)90051-5. ISSN   0003-9993. OCLC   1513891. PMID   10488999.
  17. ↑ "The right manner, the mid-frequency current". tenspros. Retrieved 1 August 2016.
  18. ↑ [Goats GC. Interferential current therapy. Br J Sports Med 1990; 24:87–92.].
  19. ↑ [Willer JC, Le Bars D, De Broucker T. Diffuse noxious inhibitory control in man: involvement of an opioidergic link. Eur J Pharmacol 1990;182:347–55.].
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