The Opioid Crisis in Central Pain

The Opioid Crisis in Central Pain

Central pain (denoted here as CP) is pain of an unusual, unfamiliar quality of sensation following an injury to the central nervous system, typically cord injury or stroke. Most patients have severe impact on the motor apparatus and would seem to the observer to have an unexpected focus on their pain compared to less focus on their quadriparesis (weakness or other muscle dysfunction) or quadriplegia (total loss of muscle function given the devastation which follows injury to the motor system of the body, where one might assume loss of movement to be a greater problem than pain).(Our heart goes out to someone we see in a wheelchair, but do we have similar feelings when we see someone in shorts or a tanktop?)

One might assume that an interruption of the pain pathway would lead to DECREASED pain. Central pain does involve decreased sensation (major or minor) as to most touch phenomenon, but both spontaneous CP and evoked CP pain from little or no stimulus appears to a disabling degree. This paradox (known as Boivie’s Paradox) as well as the unusual, unfamiliar quality of the pain (a variant of burning) cause serious problems in communication with family and all others, including caregivers unfamiliar with central pain. Because the patient regards the pain as the most severe problem and requests relief from opioids or other pain meds, they not uncommonly are mistaken for having addictive tendencies.

Dr. Ron Melzack in Canada has shown that patients with severe CP pain do NOT necessarily become addicted to opiates, although they may use them for sedation while not receiving actualy pain relief. (see “The Textbook of Pain” by Patrick Wall and Ron Melzack, eds.). Unfortunately the shelter of sedation does not help them find a suitable treatment. The pain remains.

The opioid crisis has received a great deal of attention of late, almost entirely regarding its addictive potential; and the subsequent harm to the health of Americans. A separate crisis exists as to the treatment of central pain viz. that opioids do not work in Central Pain. The torture remains. Those with the condition generally report no real analgesia, although some sedation is commonly noted. It is not clear how liable to addiction people with severe pain may as compared to those with less severe pain, but it seems likely that addiction is a threat to anyone who consumes opiates or any of the related opioids
As always, there is a problem with definitions of central pain states. There seem to be roughly four categories. In fully elaborated central pain, which co-author Ron Tasker (a famous investigator of neuropathic pain and neurosurgeon in Toronto) has called the most severe pain state known to man.

The CP victim has severe pain from light touch (paradoxical), or even with no touch (the pain often focused in the skin or just beneath ii, as well as punishing pain in the muscles (whether or not the muscle is under a load).

Some investigators (such as S.Weir Mitchell of Johns Hopkins fame) refer exclusively to fully elaborated Central Pain when the term is used. Such pain can reach the level of complete paralysis and the nature of such pain is not like any experienced prior to the injury, generally becoming more severe as one goes distally from the nerve supply from the brain (ie outward on the extremities or elsewhere on the skin surface).

Ephapses, common in CP, or pain NEAR an area which happens to be touched or stimulated are nearly always present. This causes havoc if clothing is donned which contacts the skin. Pain from cold stimulus is generally more pronounced than warmth, although both may cause pain. CP sufferers nearly always must wear abbreviated clothing and avoid muscle loading. Based on responses to questioning, the patient typically sees this as describing the stimuli which evoke bizarre burning, but they see their condition as more or less a unity, even if certain subjects include various aspects as being present. Four categories of related conditions may apply

 

Category 1 refers mainly to unclassified, possible types of central pain, not clearly neuropathic. Ah example might be a spastic bladder in someone with cord injury. 

.Category 2 CP can be thought of as those who can endure the touch of clothing and also maintain mobility, but with significant disability due to pain from muscle loading.

Category 3 includes those with any bizarre musculoskeletal pain following stroke, spinal cord, or other brain injury.

Category 4 refers to those whose pain has followed insult to the central nervous system, but may not include an unusual (ie dysesthetic) quality. This category may include some who do not actually have central pain.

This shows that the categories are not strictly ranks of severity. Pain quality is also an important part of the differentiation. One may be quite severe, as with central pain in the muscles (from muscle loading) and not respond readily to a question about dysesthesia, since burning in the muscles (which would be category 4) while severe, is not as unfamiliar in pain quality as is skin dysesthesia. How would you describe the taste of salt to someone who has only tasted sugar? We may not appreciate how it feel to be cheated if we have only known fidelity, but how much more in the dark would we be if we did not know that cheating even exists. Mankind is uncertain about the nature or reality of Hell, but the literature on the subject provides better descriptors for Central Pain than much of the medical literature on pain generally or what is termed nociceptive ie. “normal pain” by the medical literature.

When we go to the doctor and give a pain history, how is it that he (she) understands what we are saying since the doctor does not have the illness which the patient is describing. The comprehension is due to the fact the doctor may have experienced a similar pain episode himself (through voluntary self-injection of capsaicin to duplicate the pain), or at least has spoken to a sufficient number of other people who have the pain to make it understandable and believable that the patient is talking about something real. This background is utterly lacking with central pain. The doctor may speak to zero other people with central pain in a lifetime of practice and therefore miss the fact that this is something entirely novel. The history will be re-characterized into something else, OR the patient may be thought to be hysterical or confabulating, almost certainly exaggerating. People who have had ordinary pain, ,know or think they know what pain is like and will reclassify what is being related to them into dimensions that make sense, given the context of their having had pain..

Correspondingly, all pain is bad and possibly quite bad. But severity is NOT solely what makes up the disability of Central Pain. CP often blankets the bodies skin surface or else large portions of the skin are affected. A fifty percent burn feeling over the entire body can be more distressing than a 90% burn over a smaller portion of it.

The doctor should, but usually does not, inquire into how the patient’s life is being impacted. If the patient says they cannot stand the touch of clothing, this should register as indicating something very severe since the  social consequences of not wearing clothing would be overwhelming in our society. I remember discussing central pain with a female artist of some repute who, after acquiring central pain, found it necessary to acquire remote ranch land and go without clothing most of the time. She could have her art work taken into public society while she herself had to remain hidden, isolated and alone. This massive change in lifestyle should signal to the clinician that a closer look at the pain is warranted, but instead the tendency is to assume the patient is catastrophizing. Add in an unsympathetic examiner for Social Security disabiilty or a skeptical examiner for an insurance company and you find a patient who is turned away from any financial assistance at all.

If the use of any muscles and every muscle is painful, the spouse must be a model of humanity not to question what the central pain subject claims they cannot do. If the doctor as well as the disability examiner refuses to acknowledge any disability what is the spouse likely to do? Sometimes the most vital role of the doctor is to back the patient in any confrontation with a social security disability review. Who is to support the spouse? It takes a sturdy personality indeed to soldier on through this predicament. Thus, the patient is often thrust into psychological isolation and this may be reflected in many aspects of life, not the least of which is financial survival.

“Burning cold” (like the touch of dry ice), while an authentically accurate descriptor of dysesthetic CP, is not likely to find a sympathetic listener anywhere outside a top flight pain center. It just sounds too alien. The patient is truly alone and none of us do well in such a circumstance when attempting to withstand suffering.

Making matters worse, a patient with ordinary (ie nociceptive) pain may erroneously conclude they have central pain, when in fact they do not. When pseudo central pain responds to opioids, the doctor then makes a second mistake of thinking that central pain DOES respond to opiates. It may be necessary to refer the doctor to the bulletins on central pain from the National Institutes of Health to persuade the doctor that something beyond opiates should be tried.It is not totally hopeless. Some few of the pain specialists can come to the correct conclusions about whether the patient ha s central pain because of the large numbers of patients which have been seen by them prior. A consistent picture of burning pain in an area of decreased sensation is the giveaway. Experienced clinicians are much less likely to be misled, although it can be a problem even for top neurologists, to distinguish true central pain from what may seem similar because patients must use very similar vocabulary to describe what is actually ordinary pain. Like someone drowning who reaches out to grab whatever is at hand, pain patients may adopt the vague terminology of central pain as they attempt to get help for their pain. Unfortunately, this situation creates confusion in the mind of the examiner, although true CP is actually rather simple to diagnose for an experienced physician. 

The following descriptor is usually sufficient: “Bizarre burning pain following injury to the central nervous system in an area of decreased sensation”.   

Examples of world class CP clinicians include men such as Ron Tasker, George Riddoch, the great French doctor Dejerine, and S. Weir Mitchell. Even today, the vocabulary of S. Weir Mitchell is instantly recognized as accurate by the central pain patient who hears it spoken. Mitchell actually helped found Johns Hopkins Medical School after finding that soldiers who developed central pain after neck injuries in the Civil War needed a place to go for treatment and evaluation. What is amazing is that there have been ANY who recognize central pain. Such doctors can often help the patient to understand what is happening to them. The patient is generally as bad as anyone in being a poor historian, ie. using terminology belonging to ordinary pain to grossly describe central pain. What other words can they use than the conventional terms for pain?

Without a vocabulary as a scaffold for the medical history, who is to blame the patient for giving an inadequate and misleading medical history to cloud the issue for the clinician taking a medical history. Still, it is a burden lifted for the patient to finally see that they are being believed, even if the doctor must inform them that no satisfactory treatment is known. This is better than undergoing surgery which fails to improve the situation. Psychological support can sometimes help the patient survive.

NOT treating is difficult for the doctor, but at least recognition of the verity of the patients’ story can lift quite a burden. Psychological help is not what is ordinarily considered adequate therapy for an organic malady, but it is better than ineffective surgery or quack remedies. And it is definitely better than shaming, a common response to CP by the ignorant physician. The doctor, who submits a bill, is assumed to be expanding the patients database of understanding. When this is not happening, the doctor may feel uncomfortable with simply listening and learning.

If one is truly incapacitated, it helps if others are not disgusted by the disability and do not think the patient is making things up. A spouse who is able to accept the inability of the affected spouse to wear clothing is in a much better position to be understanding and to a limited extent be helpful than one whose spouse has been told they are malingering. Throw in all the hopefulness with subsequent failure of surgery and one has a perfect situation for inducement to divorce or at least becoming VERY non-supportive and unhelpful. This is a tough place to be in for the patient with severe central pain and not only divorce or estrangement from family and society, but suicide finds a fertile ground for development.

If one awakes at night in a very dark room, objects in the room lose their definition. A state close to blindness occurs. If one were to ask a person in that condition about what is in the room, it is likely that the response would not be clear, would not be explicit, and would not be satisfactory for a sighted person. The reason is that there is no light to illuminate the situation. And light is what gives definition to the environment. Something similar occurs in central pain. Words are the light of our intellectual world. If we are deprived of words, how do we proceed to describe something. And what are words. They are constructs created to describe. Without them, it is hard to start the show.Since only those with central pain (ie. the dysesthetic aspects of central pain) perceive the alien sensations of central pain, their experience is not really accessible to others. This includes clinicians who treat such patients. And yet, there is remarkable success in describing central pain by some few experts.

The experience of CP is also available to some degree by the subcutaneous injection of capsaicin. Those with central pain experience MANY types of pain but we can at least be aware that the researchers who have injected capsaicin have very similar sensations to our dysesthetic burning (sometimes paradoxically described as a “cold burn), which is the most important aspect. Dysesthetic burning is after all the most severe and perhaps the defining aspect of central nerve injury pain for most who have it, as well as the other central pains.

The descriptive efforts of men like S. Weir Mitchell are remarkably descriptive of what patients with central pain dysesthesia are experiencing, even though Mitchell did NOT have central pain, although he had extensive experience with soldiers wounded in the neck who subsequently developed central pain.

This indicates Mitchell had a very highly developed ability to LISTEN, a skill not typically so well developed in many doctors. Students in the Physical Diagnosis lectures at Johns Hopkins Medical School are told “If you listen to the patient long enough, he will tell you what is wrong with him” Today, some doctors faced with inadequate attempts by patients to describe something without an adequate vocabulary to do so, have preferred to speak of central pain syndrome. How did we get to SYNDROME? Why not simply central pain. For many years, since Dejerine and others had begun to explore this condition. “central pain”, there was no need felt to tack on “syndrome”. One definition of “syndrome” is a “characteristic combination of opinions” or a characteristic group of symptoms or signs which occur together”. We must wonder if central pain is plural or singular. For many years scientists, sometimes calling it “thalamic pain” did not think they were speaking of something plural; rather, they saw a single illness with multiple aspects. The singular sufficed for many years and it does not yet appear that the plural is helpful in understanding. Perhaps preference for “syndrome” is really just an indicator of how difficult it is to nail down in words a condition for which no accurate words exist. In such a case CP is not a syndrome, but rather it is a condition, a specific condition with an identity.

The Wall/McHenry database consists of nearly 330 subjects who had been diagnosed at pain clinics with central pain, who answered a questionaire over the internet. Over ninety percent felt the signal characteristic was “bizarre burning under the skin follow injury to the central nervous system.” It seems reasonable to conclude that this bizarre burning is the most important aspect for patients. This gathering of responses seems to justify our feeling that the original describers of central pain as an identity were justified. The word syndrome may have crept in because some were lumped in with the condition, whose entry was permitted because of the vagueness in speech or by the trouble examiners had in understanding who really fit into this category. The danger here is that certain people may be included who do not actually have central pain. The foregoing not withstanding, NIH itself is now using the term central pain SYNDROME, so we are likely in the minority at this time, but we feel fairly certain that when the underlying cause of CP is known, it will once again be termed central pain and not a syndrome, not that it matters much, unless it leads to a cessation of investigative research for a single cause, such as failure of a nucleus of cells in the thalamus.

For most patients with central pain, when they speak of central pain, they are referring to the dysesthetic burning, although if pressed can actually give better descriptions of the nondysesthetic nerve injury pains which are part of the condition, but are typically, not as impactful. This is not always the case however. Some with muscle pains have very severe, disabling impact. What is also remarkable is that many patients with central pain additionally have severe motor impairment, such as quadriparesis or quadriplegia, but nevertheless regard their central pain as more disabling. The clinician or examiner may unnerve the patient by focusing almost entirely on the quadriparesis while the patient’s concern and hope for help may be centered on the central pain. Thus, the patient feels inadequate to describe the central pains and in fact IS inadequate with the result that the patient does not feel his illness has been adequately evaluated.

Since there is no satisfactory treatment for central pain (according to the National Institutes of Health), the doctor, but not the patient, may prefer to focus on what he or she has which CAN  be treated. This further leads to frustration on the part of the patient, who is so sick that they feel frustrated in trying to convince the doctor that they are very ill, and need help with meeting the pain,  even if they cannot describe it. Even poor historians are usually very good at describing pain, a vivid medical symptom. The doctor expects this precision in vocabulary, but they too often they are unprepared for a patient alleging severe distress with a near total inability to describe their pain. There is after all, no good vocabulary and the patient must often borrow from ordinary pain (called by doctors “nociceptive or noxious pain”) to describe their “neuropathic or nerve injury pain”) ie. pain carried in an injured or dysfunctional set of nerves or a dis-integrated nervous system (presumably one where the thalamus cannot do its job of integrating sensory signals coming up through the nervous system).

It helps if the doctor will read S.Weir Mitchell, who speaks the medical lingo (giving such dimension to descriptors as can be given, but that is only a start. The best approach is to listen very carefully to the patient and attempt to understand what the patient is trying to say AND be willing to listen for a sufficient amount of time for the patient to feel he/she has been able to give some adequate expression, poor and indistinct though it may be. The patient usually assumes the doctor knows what central pain feels like. Sometimes it is the patient who must be willing to devote sufficient time for the doctor’s understanding to develop. Frequently, this may be the doctors first exposure to central pain, although this should not be the case; for example, for a neurologist who works in a spine hospital where central pain is a common occurrence.