Pain management is big business in the U.S. especially for those who make and distribute pharmaceuticals. The use of drugs can be wonderful when the drugs help to alleviate the cause of the pain impulse for the patient, but it becomes a problem if the drug is only used to mask the brain's ability to perceive pain. This is one of the techniques that is used for pain management of the chronic pain patient however there are better options..
If a patient is in chronic pain due to an incurable disease such as cancer then by all means no one wants to see another human suffering needlessly and pain management by pharmaceuticals may be the best route for the physician to take. When the underlying conditon is not terminal and pharmaceuticals are used to mask the brain's ability to perceive then many other issues are involved. Often the masking does more than mask, it also diminishes the brain's ability to be alert and aware of the patient's surroundings and in extreme cases the patient may injure themselves without knowledge it has happened. This can be extremely dangerous if the patient is operating a vehicle, working on a project that requires concentration, or the patient's inability to be alert puts another person in danger of injury.
It is far too frequent in the U.S. that our first line of defense for chronic pain is the masking of the brain's ability to perceive pain. Part of the issue is lack of education about other treatment options. Medical schools are great labs for those who sell pharmaceuticals to instruct new physicians on the benefits of their products. One physician with a life ahead of practicing medicine can represent a gold mine to anyone who can get that physician to think of their product first when dealing with pain. Also with chronic pain patients that patient becomes a "failure" to many doctors simply because the underlying pain etiology can not be determined or can not be "cured". Over time the patient's return for treatment frustrates the physician and there is few things easier than what is considered "doping" the patient with mind altering drugs. This is the area that many chronic pain patients choose to depart from traditional medicine and look for alternatives to thier chronic state of living with pain.
A method to use when pain becomes chronic is to block the transmission of the pain impulse to the brain. When the impulse is blocked then there can be no pain. For many years the method of doing this is the use of electrotherapy via tens, interferential, microamperage or high volt units. These units interfere with the pain message transmitted over the pain nerves going to the spinal cord. This is called the Melzack/Wall Gate Control Theory of Pain ( def) .
Melzack/Wall Gate Control Theory of Pain
A good comparison of this is to look at an emergency room where you have many patients entering that would not be considered "emergencies". The staff has to adjust who they will see based upon the likelihood of survival, severity of the condition, and overall staff to deliver the services to those most in need. The staff makes those determinations and then chooses who is to be seen first.
Our spinal cord also has a limited number of pathways to the brain yet it is being bombarded by many messages that the body is sending to the spinal cord to transmit to the brain. There are more messages coming in than transmission lines to the brain so the spinal cord basically chooses which messages are most important. The message of pain is generally considered a higher priority and in most situations that message gets transmitted. In chronic pain it is basically a perpetual message so the patient's brain is being constantly reminded of pain in a certain area. With chronic pain though this repetition can actually harm the patient due to disuse atrophy, poor blood flow and loss of elasticity in the cells, muscles etc. By activating other non-pain messages the pain message is not transmitted to the brain and the patient feels better , is alert to their surroundings and able to do somethng simple enhancing their lives suck as playing with grandkids, going on vacations with family, or simply being able to perform household tasks without pain.
Of course the problem then becomes what if the patient does something to cause pain to themselves and can not feel it such as touching a hot surface and burning themselves. The pain device does not mask new pain, it simply deals with the existing pain so a new impulse is not affected by the stimulus from the device. In this situation the patient would feel the new pain, burn, and the brain would then instruct the muscles to withdraw the painful area from hot area.
Melzack and Wall basically defined the process as the closing of the gate in the spinal column so it could not be transmitted to the brain.
The Sjolund study later identified the production of opioid peptides, the body's natural pain killers, as another theory of operation of how electrotherapy devices stopped pain but in practice the Melzack/Wall seems to be more efficient and has outlasted other pain theories.