Effective, Safe Pain Control With Electricity
For many decades we have been using electricity to control pain. Actually we could go back several centuries to the oft repeated use of electric eels for gout pain. The patient would put the painful part in a bucket of eels and obtain pain relief from the shock of the eels. This is our first recorded use of electricity for pain control. It does not matter whether the pain is chronic or acute as the process of sensory input for the pain sensation is practically identical. Historically tens units have been used outside the clinic for the patient to wear and adjust during their daily activities to accommodate the pain being felt. If the pain is very severe, acute onset, or the patient has moments when the pain intensity is too great for them to bear, then interferential is used in the clinical setting. In rare situations a dorsal column stimulator (DCS) will be used and in the most severe a deep brain stimulator (DBS) will be used. I'll explain each of these farther along in this email.
Physiology:
Pain is symptomatic of a problem somewhere in your body. The pain signal triggers your brain to respond to the harmful stimulus, such as touching a hot pan, by rapidly withdrawing your hand. If the hand was harmed, tissue damaged, then a new process is started by the brain to make sure there is no infectious agents such as bacteria, germs etc. in the body where the pain was experienced. The brain will signal the release of T-cells ( natural antibiotics ) to the site and will precede the t - cells with histamines so they can break through the capillaries to the area the bacteria is and kill it. The brain will cause many physiological and biological changes with the latter two being a small part of the process.
The pain stimulus is sent to the spinal column to go to the brain. It is an electrical signal that imbalances certain nerves and the resulting actions by the nerves insure the pain message is received so no further harm is done. All of this is good until the message going to the brain is continuous or more frequent than is needed and unnecessary. It is at this point when the message is constant that the patient has a problem. Now the issue is not protecting the body but preventing further harm by the constant pain message which limits the patient's abilities to be functional. The pain impulse becomes an inhibitor to health. One comment you will hear often is the pain " is all in your head". Very accurate statement as all pain is in the head as that is where it is perceived so nothing new here. The danger of it not being in your head is most evident in a patient with diabetic neuropathy or other diseases where the sensory input is lost. That patient may have a cut, or burn to their foot/legs, and never know about it until infection has set in. The impairment of the sensory input to the patient's brain results in far more serious injury often resulting in systemic infection, amputation or in some cases death. For those patients the lack of pain being in their "head" can be tragic.
How Electrical Signals To The Body Work:
With chronic pain the nerves that are transmitting the pain signal are activated by minimal input. When the pain nerve going to the spinal cord is stimulated a message is sent and the spinal cord can only accept and transmit a limited number of messages to the brain. The messages to the brain come in from different types of nerves referred to as "A", "B", "C" fibers. These fibers carry different messages such as pressure, heat etc. so the fibers have different duties (jobs) to keep the brain informed of what our body is experiencing. Because there are more nerve fibers coming to the spine than there are pathways to the brain then some messages do not get transmitted. When that message is the pain message from the C fiber, then if not transmitted, obviously there can be no pain.
If not in the brain then no pain.
With electricity for the chronic pain patient we use devices to stimulate the "non pain" fibers.
For visualization I like to compare this process to the old fashion telephone system where you had an operator who physically routed phone calls to their destination. The operator might only have access to 10 outgoing lines so when there were 20 calls coming into the central system the operator had to decide which of the 10 were most important and allow them through while letting the other 10 know to wait or call back when less busy. This is similar to the process our spine goes through on deciding what messages are allowed or not allowed.
In order to prioritize non pain messages so the spinal cord will transmit that message, rather than the pain message, we use electricity to stimulate the non-pain fibers. The electrical impulse stimulates ( causing physical/chemical changes ) to the nerve fibers and therefore the input from the non pain fibers are transmitted and the pain message is not. When using electrical inputs the patient experiences non pain sensations since that sensation is what is being transmitted to the brain for our perception. The pain signal goes away or is never transmitted therefore no pain.
At this point a word of clarification on the "blocking" of the pain message. Naturally one would assume that by blocking the impulse the patient runs risk of real injury yet it would not be perceived. That is not the case with controlled electrical input from a device. The amount of electrical stimulus in the painful area is produced based upon the existing level of pain at the time the electrical stimulus is set up. If the electrical stimulus is too great then that stimulus itself will cause the patient to have pain. The patient would react by simply saying that the electricity is now painful so the level of the intensity would be lowered so the patient experiences no pain. If after the electrical stimulus is set up and the patient now has a new injury then the pain stimulus from the new injury will override the existing settings and the new painful stimulus will override and the new injury will be just that, a more powerful stimulus that is transmitted to the brain and the patient knows of a new injury and the body reacts accordingly. This is most common in the use of electrical devices for athletes. A football player wearing a unit during a game who has suffered a "hip pointer" or "sprained ankle" would still feel any new injury or stimulus such as re-injuring the ankle. The pain from the new injury is perceived, not overridden by the electrical device.
Devices to Stop The Pain Message
Listed below are the type electrical devices normally used to stop chronic pain:
1. TENS ( Transcutaneous Electrical Nerve Stimulator ) - A small portable device worn by the patient operating from generally a 9 volt battery. Device is worn constantly, or when pain present, and can be worn 24/7 if necessary. Characterized electrically by having range of 1 - 150 pulses per second ( PPS) of electricity. PPS simply means the machine comes off and on 150 times a second. Tens have no carryover pain relief which means if the unit is turned off then the pain immediately returns. TENS are covered by most insurance companies, including Medicare.
2. Interferential Unit ( IF/IFC) - Somewhat larger than a tens unit and uses electricity from a plug in AC adaptor. The pulses per second are 8,000 - 8,150. The greater pulses per second mean an Interferential Unit can not be worn or used for any extended time period if using a battery system but needs to be plugged in to the wall. Interferential has considerable carryover pain relief and often after a 20 -30 minute treatment the pain will not return for hours/ days or weeks. Interferential is covered by some insurance companies when billed as durable medical equipment ( DME) but is regarded by Medicare as experimental.
3. Dorsal Column Stimulator ( DCS) - An external device power source that usually uses radio waves to transmit power to the receiver which is connected to wires embedded on each side of the spinal column. This is an implant requiring surgical intervention. The stimulus often results in immediate pain relief with some carryover in certain patients. Normally the surgery has to be preapproved by the insurance company and external devices have failed prior to the authorization of the implantation of a DCS.
4. Deep Brain Simulator ( DBS) - Similar to the DCS except the wires are placed into the brain. Implant done generally by a neurosurgeon and often a last resort type treatment for patients who potentially suicidal due to the severity of their chronic pain.
Electric Range - Effective, Safe Pain Control With Electricity
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