Brain Reorganization with Severe Pain: New Understanding and Challenges
As we enter the late stage of the year of the “Decade of Pain,” it is clear that the greatest clinical realization of the year, if not the decade, is that the brain reorganizes itself if severe pain is not immediately controlled after an injury or insult. The process of brain reorganization is called “neural plasticity.” In this case, the neural plasticity can only be described as negative or even malignant.
There are now a plethora of well-done and varied studies which elucidate the mechanism and outcome of what is neuroplasticity “gone bad.”1-5 If a painful, peripheral injury site occurs and fails to heal in a critical time period, the wound—which contains damaged nerves, blood, and lymph vessels—will not transmit electrical impulses down the nerve in a normal outflow pattern. The static or retained electricity at the pain site will go retrograde and, in simple terms, over-stimulate the dorsal horn of the spinal cord and some brain structures—including the amydyla and hippocampus.1-3 The end result is a permanent memory of pain imbedded in reorganized circuitry. This is basically the physiologic mechanism of phantom limb pain. Loss of gray matter and receptor sites occurs.1-3 Typically, the pain is perceived as severe, sympathetic discharge is prevalent, hormonal abnormalities occur, and high dosages of opioids may be required to control the pain.
The Clinical Problem
The problem for physicians is that we must clinically segregate the reorganized brain patient from the moderate and mild chronic pain case who only has a peripheral pain site problem. Not only do these categories of patients require different treatments, they have very different outcomes. Clearly the mild, moderate, and reorganized brain patients are different folks who need different strokes. A key question is “Is it simply enough to call the chronic pain cases mild, moderate, and severe?” I submit that we must immediately begin to identify and profile the patients with brain reorganization for the reasons I outline here:
1. Many, if not most, of the brain-rearranged patients legitimately require high opioid dosages for pain control. Patients, physicians, families, and regulatory agencies must recognize that these are tragic patients who must be vigorously treated.
2. Health insurance plans need a way to identify these needy patients who admittedly may require extraordinary expense.
3. Acknowledgement that this sub-group of pain patients exists will foster research, understanding, and strategies that may prevent the mental and physical deterioration that is becoming all too obvious in these patients.1-3
The Semantic Problem
What name should we apply to these patients? A few names for this condition have been cropping up. Names such as “persistent” sound trite. Central sensitization syndrome is a term now being categorically used to describe fibromyalgia, irritable bowel syndrome, and interstitial cystitis. Some physicians refer to these patients as having neuroplasticity. But the term neuroplasticity simply means that nervous tissue is pliable and can change for good or worse. In this case, it is neuroplasticity “gone bad.” Some physicians are calling this condition “Chronic Pain Syndrome” or “Intractable Pain Syndrome.” The term syndrome always makes the point that multiple disease processes are simultaneously present. For the moment I’m going to personally use the term “Central Brain Syndrome” and note this diagnosis as a secondary diagnosis on patient’s charts. This old term is simply defined in 50 year-old medical dictionaries as “a pain which results from a brain abnormality.” It has classically been used in pain patients who had a brain disease such as a stroke, multiple sclerosis, or myesthenia gravis.
The Key Issue
Even more important than the name or names that various physicians may apply to this condition is its recognition. This malady needs to be diagnosed by clinical signs, symptoms, and historical information like any other disease. We can’t rely on magnetic resonance imaging (MRI)—not only is it expensive, but the neuroplastic changes are cellular and may not show on an MRI. This editor wants to immediately hear from any physician who has a name suggestion and/or a check list of signs, symptoms, and historical data to help us profile and identify these patients from among the general pain population. We will publish our first shot at this in our next issue. Admittedly, we’re early in this pursuit and we won’t be initially perfect, but we must start identifying these patients and developing therapeutic strategies to help them.