Head Trauma: More Than A Headache
The common belief of most pain practitioners is that head trauma produces a severe headache that may require specialized pain treatment—no argument here. New clinical and scientific observations, however, tell us that the headache may just be the tip of the iceberg. The name usually applied to a head injury today is traumatic brain injury, or TBI.1 It is one of the most common human afflictions and also one of the most poorly understood.
According to the Centers for Disease Control and Prevention, at least 1.4 million people sustain a TBI each year in the United States. Of these, about 50,000 die, 235,000 are hospitalized, and 1.1 million are treated and released from an emergency room department. Falls are the leading cause of TBIs, noted the agency, with fall rates highest for children ages 0 to 4 years and for adults aged 75 years or older.2
By definition, TBI is an injury to the brain that comes from an outside mechanical force (such as a blow, whiplash, blast waves, or projectile), which impairs brain function. When this happens, especially with loss of consciousness or bodily functions, a patient is said to be concussed.3 What is rarely understood is that a concussion is more than a "ding," and far more than "getting your bell rung."
TBIs, in fact, cause a wide variety of symptoms ranging from memory loss and confusion to mood swings; reading, speaking or reasoning problems; as well as problems understanding what is being said, learning new things, or dealing with old familiar things like time, numbers, or money. There may be severe difficulty sleeping, abnormally low body temperature, weight gain, confusion, explosive behavior, or terrible fatigue. Loss of interest in hobbies, friends, and sex are also common. It may be enormously difficult or impossible to organize and prioritize, to sequence events, or to do more than one thing at a time (multitasking). Watching movies or sports may be physically and mentally painful. Being in noisy or brightly lit places can be intolerable. Social skills may deteriorate. In children, they may fail to develop. Table 1 outlines many TBI manifestations.
Besides the abnormal behavior that TBIs may cause, there are three sequelae that may confound pain diagnosis and management. The first is hypothalamic-pituitary dysfunction.4 Any number of deficiencies including adrenal, gonadal, and thyroid may result. Second, pain, besides headache, may occur and it usually presents like fibromyalgia.1 In fact, I've been referred patients with a diagnosis of fibromyalgia who really had centralized pain secondary to TBI. Most of these patients complain of pain "all over" that is muscular in nature. The third sequela is that head trauma may induce an autoimmune inflammatory disorder. One working theory, in addition to hypothalamic-pituitary dysfunction, is that damaged brain tissue leaks through the blood-brain barrier into the general circulation and becomes, in fact, an antigen just like a virus or allergen. Antibodies are formed against brain tissue that may become "auto" and start to attack various tissues including the brain itself. Regardless, an autoimmune inflammatory disorder may develop after head trauma and not only cause joint and muscle pain but attack other organs such as the eye, lung, heart, liver, intestine, and kidney—just like any autoimmune inflammatory condition.
Interest in TBI has grown recently, partly because of improved recognition and reporting of the disorder—especially among high-profile contact sports athletes and returning soldiers from Iraq and Afghanistan. In the 1920s, the neurological deterioration in "punch drunk" boxers who fought with bare hands was called "dementia pugilistica"—the madness of fighters. Today, it is often called chronic traumatic encephalopathy. Research has shown that degeneration of brain tissue may occur and accumulate an abnormal protein designated as "tau."
Recently, I surveyed—with a short, written questionnaire—50 of my patients during a couple of routine clinic days. Much to my surprise, about 25% claimed that head, neck, or face trauma had either started or worsened their current pain problem. I now believe that we must all start taking a history of head trauma, if for no other reason than to explain some of the odd behavioral manifestations that we see in some pain patients. For more on TBIs, please see a review article by John Claude Krusz, PhD, MD, and Lawrence Robbins, MD, on the treatment of postconcussional migraines and headaches as well as case reports of US active duty soldiers with polytrauma presented by David X. Cifu, MD, and colleagues.