PART 1 CONCUSSION/MILD TRAUMATIC BRAIN INJURY: AN OVERVIEW INTRODUCTION Lynn, a 26-year-old dental hygienist, was driving to work one morning when her car was rear-ended at a red light. The fifteen-mile-per-hour impact caused no damage to either vehicle, and the seat belt kept Lynn's body in place. Only her head moved, quickly snapping forward and back. Lynn felt momentarily disoriented, but the feeling passed, and she went on her way without giving the matter much thought. By lunchtime, Lynn had a severe headache. By evening, she also felt nauseated and extremely tired. At first, Lynn suspected a virus. But as the days passed, her headaches escalated and her fatigue increased. She also began to have problems sleeping, concentrating, expressing herself, and making decisions. To others, Lynn seemed uncharacteristically short-tempered and forgetful, and this led the puzzled young woman to see her physician. The eventual diagnosis? A concussion, also referred to as a mild traumatic brain injury (mTBI), a result of the now months-ago incident at the traffic light. • • • LYNN'S STORY is not at all unusual. In fact, each year millions of people worldwide are seen in hospitals, suffering from concussions. Many more visit doctors' offices and walk-in clinics, or may not even report the event, which is why concussion has come to be called "the Silent Epidemic." The principal causes of TBI are falls, motor vehicle accidents, blows, assaults, sports injuries, blast injuries, and violent movements such as whiplash. Like Lynn, a significant number of those who incur a concussion suffer debilitating aftereffects-- post concussion syndrome (PCS)--for months or years afterward despite what is usually a perfectly normal outward appearance. Part 1 of this book will help you better understand this phenomenon by providing a detailed look at the brain and brain function as well as the causes, significance, and evaluation of concussion. CHAPTER 1 WHAT IS A CONCUSSION/MILD TRAUMATIC BRAIN INJURY? In the course of everyday life, you have little reason to think about the workings of your brain, even with television ads and magazine articles presenting the relationships between eating, sleeping, and brain health. However, if you have suffered a concussion, also called mild traumatic brain injury (mTBI), or know someone who has, the subject takes on sudden importance. As with almost any injury, knowledge about the affected organ--the brain, in this case--will help you and your family to better understand your symptoms and maintain a sense of control over the recovery process. It is likely that you've attempted an Internet search for answers to your questions about your injury, symptoms, and treatment, only to feel overwhelmed by the quantity of information available. If so, you have probably wondered where you can find information that is accurate and leads to the answers you need. This book is intended to provide just that: the most recent research, verified by experts and presented in a concise, easy-to-use format. A LOOK AT THE BRAIN The human brain weighs about three pounds and is the most complex of organs--an intricate network of some 200 billion nerve cells and a trillion supporting cells. It is nourished by a vast network of blood vessels that supply the oxygen and glucose needed to fuel the brain. Your diet, quality of sleep, degree of stress, hormonal factors, and general quality of life directly affect your brain function, impacting all bodily activity from heart rate and movement to emotion and learning. The brain's complex components include veins, arteries, capillaries, threadlike nerve fibers, connective networks, neurotransmitters, neuromodulators, and hormones, which are involuntarily reactive to both internal and external events. Only a small portion of the brain operates in a voluntary, responsive manner; thus, brain function determines a person's abilities, personality, and state of health, all the while creating a capacity for thinking, feeling, imagining, and planning. While the human skull is hard and bony, the brain within has been likened to custard in a bowl--soft, pliable, and slippery (Figure 1.1). Directly beneath the skull are three thin membranes called meninges that hold pockets of air and about a coffee-cupful of cerebrospinal fluid (CSF), which cushion the brain and its circulatory network. Figure 1.1. A cross-section of the brain. This network, composed of arteries and veins (Figure 1.2), nourishes the brain, with each heartbeat providing oxygen and important nutrients as fuel. The countless small branches off the arteries and veins are called capillaries (Figure 1.3). Figure 1.2. The brain and its arteries. Figure 1.3. The brain and its veins and capillaries. Directly beneath the meninges is the brain's wrinkled gray and white matter, made up of four distinct areas of brain functioning. These include the brain stem , midbrain , limbic system , and cerebral cortex . Of the four areas, the frontal area of the cerebral cortex is the most voluntary (responsive) to internal and external events. The cerebral cortex, sometimes called the cerebrum , is the top layer of the brain and is its largest and most advanced part. It controls problem-solving, planning, and judgment, as well as movement and sensory activity. This area is divided into two halves, or hemispheres--the left and the right. One curious fact about brain function is that the right hemisphere, or the right side of the brain, controls the left side of the body, while the left hemisphere controls the right side of the body. In addition, the right hemisphere governs aspects of creativity, intuition, and nonverbal communication--gestures, facial expressions, and the like--and is referred to as the nonlinear mind. The left hemisphere, called the linear mind, is responsible for logical thinking, mathematics, and verbal and written expression. Both of the hemispheres are subdivided into parts called lobes, each of which controls specific body functions (Figure 1.4). The frontal lobe , located closest to the forehead, controls emotions and behaviors, social and motor skills, abstract thinking, reasoning, planning, judgment, and memory. Broca's area , situated at the base of the frontal lobe, helps to govern speech. This area of the brain, especially the prefrontal area, is the area that governs voluntary responsiveness. It is similar to a symphony conductor, instructing areas of the brain that are voluntary and reactive. Figure 1.4. A look at the cerebrum. The parietal lobe is located halfway between the front and back of the skull. This area is responsible for sensory and spatial awareness, giving feedback from and understanding of eye, hand, and arm movements during complex operations such as reading, writing, and numerical calculations. At the center of the parietal lobe is the angular gyrus , a fold in the surface of the brain where visual messages, such as words that are read, are matched with the sounds of spoken words. At the back of the head, behind the parietal lobe, is the occipital lobe , which controls vision and recognition. The temporal lobe is located beneath the frontal and parietal lobes and has an influence on emotions. The temporal lobe plays a part in smelling, tasting, remembering information, noticing things, comprehending music, and categorizing objects. It also plays a role in aggressiveness and sexual behavior. At the back of the left temporal lobe is Wernicke's area , which is responsible for hearing and interpreting language. Beneath the cerebrum are a number of internal brain structures (Figure 1.5). The thalamus acts as a nerve-impulse relay station for information coming into the brain, passing it to the cerebrum to be prioritized and transmitted throughout the body. The hypothalamus is located beneath the thalamus and influences sex drive, sleep, long-term memory, and the expression of emotion perceived by the brain, passing information to the pituitary gland that helps regulate and stabilize various hormones in your body--part of your neuroendocrine system . Figure 1.5. The inner structures of the brain. The limbic system and components such as the amygdala are the source of involuntary survival reactions to perceived danger. Other components include the endocrine and autonomic nervous systems, which reactively control your breathing, heart rate, and digestive and intestinal systems (Figure 1.6). The limbic system is the link between the cerebral cortex, midbrain, and brain stem. Its components help the hypothalamus prioritize incoming information and also play a vital part in controlling memory, pain, and emotions. Figure 1.6. The limbic system. At the central rear of the brain is the brain stem, which contains the midbrain, the pons , and the medulla oblongata . These structures control breathing and heartbeat and serve as a relay station for all motion and sensation. The cerebellum, a part of the brain situated in a cupped position slightly above the brain stem, oversees movement and balance, while the hippocampus , centrally located next to the temporal lobe near the base of the brain, is a key area in the creation of new memories and the transition of short-term memory to long-term. Each part of the brain is highly specialized and is able to do its job only because of a vast network of nerve connections through the white matter (Figure 1.7), which includes specific neurotransmitters, neuromodulators (chemical messengers), and neuroconnective hubs (electrical connectors) for clearly defined tasks, functions, and processing. Figure 1.7. The white matter. It is the electrical system of the brain that allows communication between the various parts of the brain. The brain contains over 100 billion neurons , or nerve cells. Each neuron consists of a cell body and conducting fibers called branches (Figure 1.8), similar to the vast network of roads that enable us to travel from one place to another. These branches can be as short as a fraction of an inch or as long as several feet and connect to a trillion other branches through specific hubs. As a comparison, consider a dirt road that leads to a cul de sac, or a superhighway that can take us across the country. The electrical impulse travels toward the end of a nerve fiber, also called the axon. Between the ends or along the sides of each branch are tiny gaps called synapses (Figure 1.9). Most synapses are at the end of a nerve, though there are additional types (Figure 1.10). Figure 1.8. The neurons and branches. Figure 1.9. A synapse. Figure 1.10. Additional types of synapses. When working properly, a neuron transmits electrical impulses to adjacent nerve cells at speeds of up to several hundred miles an hour. The electrical signal that is formed pulses at differing rates of speed, creating a push/pull effect similar to the ebb and flow of the ocean. These electrical signals are called brain waves, and their speed is measured in electrical units called hertz (Hz). In 1940, W. Gray Walter was the first to identify that different brain waves have different effects on how we function. Table 1.3 shows different brain waves, their frequencies, and what they do. Individual brain waves work together as a team to send signals to different parts of the body, operating much as your car does when all the wheels are in alignment. The synapses play a critical role in how the brain enables us to function, similar to the activity at a busy toll plaza. The brain's nerves are not in direct contact with one another, and the synapse between each nerve regulates functioning through a burst of chemicals called neurotransmitters (Table 1.1) and neuromodulators (Table 1.2), each of which has a specific task. Neurotransmitters are similar to traffic lights that signal electrical impulses to stop (inhibit) or go (activate), controlling whether the impulses continue. Neuromodulators are similar to police officers controlling traffic at busy intersections, overseeing a gradual flow of traffic in all directions. Neurotransmitters are chemicals that allow the movement of information across the synapse, or gap, between one neuron and an adjacent neuron. A neurotransmitter functions similarly to a traffic light, or a driver putting a foot on either the accelerator or the brake in a car. NEUROTRANSMITTER BEHAVIOR PURPOSE Glutamate This chemical acts like a green light or a car's accelerator, telling the system to go. It permits the electrical signal and its purpose to communicate to the next nerve. Glutamate is called the excitatory neurotransmitter and . . . Is involved in most aspects of normal brain function including cognition, memory, and learning Mediates a good deal of information, including that which regulates brain development and that which determines cellular survival Gamma-Aminobutyric Acid (GABA) This chemical acts like a red light or a car's brakes, telling the system to stop. It stops the electrical signal from continuing to the next nerve. GABA is called the inhibitory neurotransmitter and . . . Contributes to motor control, vision, and many other cortical functions Regulates anxiety Helps stimulate relaxation and sleep Stabilizes the brain by preventing overexcitement Neuromodulators are chemicals that do not directly activate or inhibit; rather, they are similar to the police officer who regulates and coordinates traffic flow. Neuromodulators work together with neurotransmitters, enhancing the excitatory ("go," or "go with caution") or inhibitory ("stop," or "slow down") responses of the receptors. Each of the neuromodulators has specific functions, as seen below. NEUROMODULATOR FUNCTION Dopamine Regulates and limits cortical and subcortical signals to the brain Can either activate or inhibit Controls arousal levels in many parts of the brain Is vital to the provision of physical motivation Governs internal control of sustained attention Modulates attention to sensory input Serotonin Acts as a feel-good chemical Influences sustained arousal and electrical impulses in the brain, and controls the feeling of well-being Has multiple roles regarding sleep, temperature regulation, sexual behavior, appetite, learning, memory, anxiety, mood, and endocrine, muscular, and cardiovascular function Impacts the regulation of one's pain threshold Is not connected to sensory input Acetylcholine Activates motor neurons that control skeletal muscles Controls activity in the brain area connected with attention, learning, and memory Is involved in central nervous system responses, including wakefulness, attentiveness, anger, aggression, sexuality, and thirst Histamine Helps regulate and modulate the activation of electrical signals Is involved in the body's inflammatory response Noradrenaline (also called norepinephrine): Helps regulate and modulate the activation of electrical signals Is active in the startle response Enhances emotional memory Contributes to the modulation of mood and arousal Is critical to attentiveness, emotions, sleep, dreaming, and learning Is released as a hormone into the blood, where it causes contraction of blood vessels and increased heart rate Aspartate Helps regulate and modulate the activation of electrical signals Regulates the metabolism of amino acids for kidney and central nervous system function Glycine Helps regulate and modulate the inhibiting of electrical signals Helps regulate the central nervous system, especially the brain stem These electrical impulses combine with the chemicals to connect one branch to another, forming vast networks of neurons in the brain's white matter. These networks meet at specific hubs to enable particular brain functions. For example, there is a hub for attention, and another for memory (Figure 1.11). Figure 1.11. White matter with various hubs. Many factors influence the push-and-pull activity of brain waves, including the aforementioned blood flow, quality of the nerve fiber, and impact of neurotransmitters, neuromodulators, and hormones. In 1929, Hans Berger first identified and named Alpha and Beta waves, while E. D. Andria and Brian Matthew named Delta and Theta waves in 1930. Since then, many others have identified additional waves seen below. Figure 1.12 illustrates a brain wave and shows its height and cycle duration. The height is the quantity of the wave being produced, or the amplitude. The duration reflects the time the cycle takes to repeat itself. The wave's frequency, or number of cycles per second, is the inverse of the duration of one cycle in units of hertz. Figure 1.12. A brain wave. The brain and body systems are also strongly affected by hormones, chemicals that are released from cells and glands. These effects include: Stimulation or inhibition of growth Mood swings Sleep Induction or suppression of apoptosis , or programmed cell death Activation or inhibition of the immune system Regulation of metabolism Preparation of the body for mating, fighting, fleeing, and other responsive activity Preparation of the body for a new life phase, such as puberty, parenting, and menopause Control of the reproductive cycle Hunger cravings Sexual arousal BRAIN WAVE EFFECTS ON BRAIN FUNCTION Delta (0.5 to 4 Hz) Are predominant during sleep Should be low while awake Repair the brain Serve as emotional radar Are responsible for intuition and unconscious thought In abundance, can interfere with emotional or cognitive processing Theta (4 to 8 Hz) Present during pre-sleep or trance state Promote insight and meditation In abundance, can create inattentiveness, distractibility, and lack of focus Alpha (8 to 12 Hz) Promote relaxation Serve as gateway for restorative sleep In abundance, can make you spacey, unmotivated, inattentive, and depressed SMR (12 to 15 Hz) Are related to calm external attention Regulate impulsivity and hyperactivity Promote body awareness Help control anxiety and anger Promote the inhibition of movement Beta (15 to 20 Hz) Are related to active external attention Enhance cognitive processing Improve concentration, attentiveness, and focus High Beta (20 to 36 Hz) Are related to body tension Promote a high state of arousal Result in excitement, anxiety, and stress Related to post traumatic stress disorder (PTSD) Gamma (36 to 64 Hz) Are linked to intellectual comprehension Are related to creativity Promote integrative thinking For instance, melatonin is a chemical that helps you sleep at night. If your electrical system is working properly, it sends a message for this chemical to be released when it is dark and you are fatigued, thereby helping you sleep. As expected, there is ebb and flow present. If the electrical impulse can't reach the cell or the melatonin can't reach the proper area, the system doesn't work properly and sleep patterns are disturbed. Now that you know how the brain functions under normal circumstances, we can look at what happens when a concussion causes dysregulation in the brain. Whether structural damage to the brain's gray or white matter is apparent or not, the aftermath of a brain injury results in dysregulation in the function of the lobes, hormones, neurotransmitters, neuromodulators, or hub activity. This dysregulation is the underlying cause of the problems seen in post concussion syndrome (PCS) in areas such as mood, behavior, sleep, fatigue, or intellect. The following chapters explore the various causes of concussion and how the resulting dysregulation of the brain is diagnosed. In addition, information is provided on approaches to treating the symptoms of PCS. CHAPTER 2 SYMPTOMS OF CONCUSSION/MILD TRAUMATIC BRAIN INJURY As mentioned earlier, injury to the brain from an outside force is called a traumatic brain injury, or TBI. Most people who experience severe brain trauma display language, motor, or perceptual problems that can be traced to a particular incident or event that caused a specific type of brain damage. Mild traumatic brain injury (mTBI), also called concussion, is characterized by a loss of consciousness ranging from negligible up to an hour in length, along with a loss of memory of events before and/or after the time of injury. Concussion can occur from a variety of causes. Automobile accidents account for the majority of cases, followed by, in order of prevalence, falls, assaults and other violence (including physical abuse), sports- and recreation-related accidents, and blast injury. The last three causes weren't linked to TBI for years; thus, diagnosis and treatment have been almost completely overlooked until recently. Now it is clear that even a small dysregulation of the brain can have an enormous effect on one's life. Some people suffer no ill effects at all following a concussion, while others encounter persistent problems and feel the effects of their injury in every aspect of life. In addition to suffering from head or neck pain, many people feel disoriented and experience memory loss immediately after the blow. These complaints often resolve within a few minutes, but over the next several hours it is common to experience an onset of dizziness, nausea, headache, and fatigue. Depending on the number of concussions experienced by an individual and the location of the brain injury, symptoms are frequently misdiagnosed or missed altogether. However, a week or two later, as the person attempts to resume normal responsibilities at home, school, or work, he or she may encounter another group of symptoms that have collectively come to be called post concussion syndrome (PCS). These complaints include persistent headaches; fatigue; impaired attention, concentration, and decision-making ability; sleep disturbances; dizziness; gait imbalance; loss of taste and smell; loss of sex drive; intolerance for alcohol; reading and communication difficulties; and emotional or behavioral problems. These symptoms may appear alone or in any combination. A concise list of common concussion aftereffects is presented in Table 2.1. In 2009, the International Symposium on Concussion changed its labels of simple and complex concussion to acute concussion and post concussion syndrome. Despite the change in terms, the core features of these conditions remain the same. ACUTE CONCUSSION An acute concussion is a temporary disruption of brain function that results in an alteration or loss of consciousness, and one or more of the memory symptoms contained in Table 2.1. Acute concussions spontaneously resolve within a week or two with rest and proper diet. This occurs due to spontaneous healing, a re-regulation of brain and nerve tissue, or the formation of new nerve-cell pathways that bypass damaged circuits (which characterizes the brain's neuroplasticity, or ability to change itself). With this type of concussion, symptoms can be treated by your primary care physician (PCP) or by a certified athletic trainer or coach working in conjunction with your PCP. POST CONCUSSION SYNDROME (PCS) When concussion symptoms do not resolve within a week or two of disrupted brain function, the label post concussion syndrome (PCS) is applied. Along with the various symptoms contained in Table 2.1, PCS can also include convulsions. With this type of condition, it is important to be seen by a neurologist who has expertise in treating concussion. PHYSICAL DIFFICULTIES Fatigue Sleep disturbances Sensitivity to light and/or sound Headaches Falling asleep unexpectedly Dizziness Nightmares or flashbacks Nausea and vomiting Alertness upon waking, followed by exhaustion Blurred vision Hand or leg tremors Sexual dysfunction or loss of sex drive Gait imbalance Ringing in the ears Loss of taste and smell COGNITIVE (THINKING) PROBLEMS Distractibility Disorientation Temporary amnesia Long- or short-term memory problems Poor judgment Slow thinking Inability to focus attention Problems with speaking Word-finding problems Feelings of confusion EMOTIONAL DIFFICULTIES Depression Agitation Apathy Irritability Fear of "going crazy" Frustration or anger Guilt or shame Feelings of helplessness Anxiety Frequent mood changes BEHAVIORAL PROBLEMS Confrontational demeanor Explosive temper Fearfulness Impatience Thoughtlessness Hypervigilance MULTIPLE CONCUSSIONS When an individual has had multiple concussions due to repeated impact to the brain, natural and spontaneous healing and regulation are unlikely. This phenomenon affects nearly 90 percent of people who experience a concussion. Repeated brain injuries, including multiple concussions, can have severe or even fatal outcomes, especially when the second injury occurs soon after the first and before recovery from the first has taken place. Each repeated injury causes further dysregulation and exponential exacerbation of symptoms. This means that each injury is not simply an additional injury, as in 1 concussion + 1 concussion = 2 concussions. Instead, each injury is a multiple of the others. Thus, the effects of a third concussion are many times worse than those of the original concussion. That is why a slight blow to the head months after an initial injury can result in more, more severe, and longer-lasting symptoms than accompanied the first concussion. Multiple concussions can result from many causes that may seem subtle or incapable of injuring the brain. Multiple concussions are divided into two categories: second impact syndrome and chronic traumatic encephalopathy. SECOND IMPACT SYNDROME (SIS) Second impact syndrome, or SIS, has been reported when a second concussion occurs within hours, days, or weeks of a previous brain injury. This happens frequently in sports and recreation participation, when a player suffers a concussion and resumes physical activity days later, only to receive another such injury. Yet many players, parents, and coaches have long felt that a concussion need not restrict continued involvement in a sport. Fortunately, this belief has changed with better understanding of brain injury's long-term consequences, such as chronic headaches, fatigue, and difficulty concentrating. CHRONIC TRAUMATIC ENCEPHALOPATHY (CTE) Chronic traumatic encephalopathy , or CTE, is a progressive neurodegenerative brain disease that appears to be caused by brain trauma (Figure 2.1). CTE evolves slowly over decades. Research has shown that the protein tau, necessary to the integrity of nerve fibers, gradually falls apart and destroys both the white and gray matter of the brain. There are three stages of CTE: Stage 1. Includes changes in mood, behavior, and cognition. An individual may become moody, angry, or combative, while his or her thinking doesn't seem to make sense. Stage 2. Includes problems with maintaining social activity, erratic behavior, and memory loss, as well as symptoms of Parkinson's disease that include a mask-like look to the face and movement problems. Stage 3. Characterized by progressive deterioration into dementia. CTE is most prevalent in boxers and football players who have suffered repeated blows to the head over an extended time period. CTE is also seen in individuals who served in the military. An in-depth explanation of sports, recreational, and blast injuries will be presented in Chapter 4. Figure 2.1. A look at CTE. ADDITIONAL SYMPTOMS The various physical, emotional, and behavioral symptoms that can follow a concussion are likely to be compounded by social and psychological factors. Because post concussion problems are often invisible to the casual observer, the injured person often hears such comments as "You look wonderful!" or "Thank goodness it was only a concussion!" or even "It's great that you're already back in the swing of things!" Of course, the person isn't feeling wonderful at all and is painfully aware of not functioning as he or she used to. This causes many people with a concussion to feel anxiety and a loss of confidence, both of which can reveal themselves in out-of-character behavior such as self-involvement and extreme vulnerability to stress. Worse still is the fact that by the time concussion consequences begin to disrupt an individual's life, he or she may not even connect the symptoms to the accident that caused them. It is no wonder, then, that after weeks of seeing little or no improvement in their symptoms, many people with a concussion find themselves facing another roadblock: persistent depression and underlying grief from the loss of self. Perhaps the greatest impact of concussion is psychological. An unexpected, unexplained inability to function can shake you to the core. Consider the insurance agent who suddenly struggles to remember clients' names and navigate the office complex, or the student who can no longer stay focused on class work and note-taking, or the mechanic who can no longer reassemble an engine. None of these people look any different from before, but all are having difficulty at work or school and are quite likely also struggling to cope with everyday chores and concerns at home. Many people with PCS begin to second-guess their every move in an attempt to avoid failure and embarrassment. This sort of anxiety can easily initiate a vicious cycle, building to such proportions that it actually contributes to cognitive problems, which in turn make the anxiety worse, and so on. It is reassuring to know that there are methods of treatment that can help you recover from your symptoms. CHAPTER 3 TYPES OF CONCUSSION/MILD TRAUMATIC BRAIN INJURY There are two types of traumatic brain injury: injury accompanied by visible external damage, and injury without visible evidence. In what was formerly called an open head injury , the skull is penetrated. Brain damage takes the form of a focal injury --that is, injury to a specific area of the brain--such as that from a gunshot wound or severe external trauma that causes the brain to swell. In a concussion without visible evidence, once called a closed head injury , the skull is not penetrated. Brain damage occurs as a result of an external force that causes the brain to move within the skull, producing any combination of the following: focal (direct contact), diffuse, rotation, sound pressure, or generalized injury. The human skull and the underlying fluid-filled membranes rarely sustain damage during a concussion (also called mild traumatic brain injury , or mTBI). Any time the head is subjected to violent force, sound, or motion, however, the soft, floating brain is slammed against the skull's uneven interior. Sometimes it rotates in the process. When this happens, the brain's threadlike nerve cells are stretched, strained, and even torn at the point of impact (focal injury, or direct contact) or in a widely scattered fashion ( diffuse injury ) or both. Many times, such an accident causes both stretching and tearing of nerve fibers. While this nerve-cell damage is usually microscopic, the effect on the brain's neurological circuits is significant, causing dysregulation of specific areas or hubs or throughout the entire system. DIRECT CONTACT FORCE CONCUSSIONS Impact injuries, or direct contact force concussions , result in observable tissue damage in a particular area of the brain. One common type of direct contact force injury occurs during car accidents and sports collisions that involve acceleration followed by rapid deceleration--that is, when the forward-moving head comes to a sudden stop after striking a stationary object. When this happens, the brain keeps moving forward until it collides with the front of the skull.This acceleration/deceleration impact causes fronto-temporal lesions , or bruising of the frontal and/or temporal lobes of the brain, as shown in Figure 3.1. This type of injury generally affects a person's ability to memorize, plan, concentrate, and/or control behavior--skills that are largely regulated by the frontal and temporal lobes. You may have sudden difficulty storing and retrieving new information, be unable to organize your thoughts, be highly distractible, or have problems modulating your behavior. These impairments result from disruption of the nerve connections between the cerebrum and the inner brain, which is in effect a neurological short circuit. Figure 3.1. An acceleration/deceleration injury. A second type of direct contact force brain injury is the coup/contrecoup (literally, "blow/counterblow") injury. Generally, this trauma occurs when a moving object makes contact with the head, briefly denting the skull inward. The brain beneath is bruised first at the point of impact and then is thrown against the opposite side of the skull, where additional bruising takes place, as shown in Figure 3.2. In coup/contrecoup injuries, the site of bruising and the resulting impairments depend on where the initial blow landed. You may encounter one or more of a range of problems, including personality changes, perceptual and sensory problems, difficulty expressing yourself, and balance and motor problems. Figure 3.2. A coup/contrecoup injury. DIFFUSE AXONAL INJURY (DAI) A mild blow to the head that causes momentary alteration or loss of consciousness with no observable disruption of nerve impulses is called a diffuse axonal injury (DAI), shown in Figure 3.3. DAIs are commonly caused by whiplash injury. It was long believed that diffuse axonal injury caused only a brief short-circuiting within the brain. However, it is now known that the stretching of nerve cells due to brain movement in multiple directions simultaneously interferes with their ability to fire impulses, thereby causing dysregulation. This leads to alteration or loss of consciousness and in turn a general disruption of mental processes. People with DAIs process information slowly, have trouble splitting their attention between tasks, and often find themselves struggling to organize and sort the details of incoming information. Abstract thinking may be impaired, as may the ability to express thoughts accurately and clearly. DAIs can occur either alone or in conjunction with a direct contact force brain injury. Figure 3.3. A diffuse axonal injury caused by whiplash. ROTATION INJURY Sudden rotation of the brain in the absence of a direct blow or whiplash movement can cause symptoms of dysregulation of connections and circuitry known as rotation injury . This type of injury occurs from violent movement of the head with or without contact, commonly occurring during recreational activities or sports. Figure 3.4 illustrates rotation injury. Figure 3.4. A rotation injury. BLAST INJURY The explosion of a bomb or improvised explosive device produces a sound wave called a supersonic wave. The movement, amplitude, and duration of this sound wave result in sufficient pressure within the brain to cause actual tissue damage along with dysregulation of connectivity and brain waves. An individual does not have to be physically moving or in contact with the blast for the injury it causes to be enormous. This damage to the brain is called blast injury , illustrated in Figure 3.5. Figure 3.5. A blast injury. Most of the brain cells, branches, hubs, neurotransmitters, neuromodulators, and hormones affected by a concussion receive only minor damage and eventually return to normal functioning. It is the parts of the brain's neuroconnectivity that are damaged or destroyed by overstretching, tearing, bleeding, and/or swelling that ultimately shape an individual's post-injury experience, because the resultant dysregulation results in post concussion syndrome (PCS), as described in Chapter 2. If there are cumulative injuries, the effect of these minor blows, rotations, or falls becomes a foundation for ongoing symptoms and determines the severity and duration of recovery from PCS. Chapter 4 addresses the issue of multiple concussions in more detail. CHAPTER 4 LEADING CAUSES OF CONCUSSION/MILD TRAUMATIC BRAIN INJURY When considering the cause of a concussion, also called mild traumatic brain injury (mTBI), it is important to recognize the significance of age, gender, and the circumstances surrounding the injury, such as a motor vehicle accident, fall, assault or violent shaking, recreational activity, blast injury, or sports collision. Age and gender have a surprising effect on one's risk of concussion. Until the age of 15, males and females have an equal risk. Between the ages of 15 and 24, males are at higher risk of this type of injury. A male's risk remains slightly higher during the working years, due to the greater likelihood of participation in physical occupations. After age 64, the risk of concussion for males versus females is again equal. INFANCY AND CHILDHOOD In infancy, the number-one cause of concussion is shaken baby syndrome, followed by falls and motor vehicle accidents. In childhood, the leading causes of concussion are domestic violence, motor vehicle accidents (even when restrained in a safety seat), and being struck by a car while walking or riding a bicycle or scooter. Seemingly benign amusement park rides also increase a child's risk. The sudden acceleration and deceleration of roller coasters and other rides are known to cause concussion, particularly if this impact is preceded by other concussions. It is likely that concussions related to riding toys are underreported, because the parent or caregiver may focus on external injuries such as scrapes or bruises. It is easy to overlook a child's appearing dazed and shaken if her knee is bleeding or his arm is injured. Even when an injury is serious enough to warrant a trip to the emergency room, the focus tends to be on the visible. Medical personnel may overlook that a child seems to be dazed or not thinking clearly, which is why concussion is called "the Silent Epidemic." Increasing numbers of children now engage in sports activities at early ages when their brains are still developing. It is not uncommon to see 4- and 5-year-olds on skis or snowboards, horses, rock-climbing walls, or snowmobiles. In addition, small children are increasingly encouraged to participate in organized sports. Along with these pastimes is time spent in classic recreational settings such as playgrounds and climbing areas, all of which carry the risk of concussion from a fall that can occasionally happen despite supervision and safety precautions. By the age of 10, many children are involved in one or more organized sports, whether played on a court, rink, or field. Individual sports such as figure skating, gymnastics, dance, and karate are strongly in play by this age as well. A pre-teen's choice of recreational activity also impacts his or her risk of concussion, be it skateboarding, roller- or ice-skating, diving, or just wrestling with a friend. THE TEEN AND YOUNG ADULT YEARS Between the ages of 14 and 25, most athletes work at increasing their skill level in order to remain competitive with peers, making sports participation more risky. Along with this comes an increase in gym workouts and aggressive recreational activities such as trampoline, racquetball, and bungee jumping. Table 4.1 presents some of the leading recreational activities pursued by teenagers. During the teen years, nutrition frequently becomes worse as parental regulation decreases and the temptation increases to use energy drinks, bodybuilding supplements, alcohol, and drugs. All of this puts the developing brain at risk, because the connective myelin in the prefrontal lobe, which helps regulate how we think, behave, and feel, is just beginning to grow. Yet it is during this time of life that many youths are involved in hard-hitting or risky athletic pursuits. Because concussion is so often invisible before the age of 16, it is thought that most children suffer at least one concussion that is either never identified or is misdiagnosed. Parents, doctors, and coaches often dismiss the fact that a child cannot remember the score of a game or seems distracted. In fact, these symptoms of concussion are often seen as attention deficit disorder (ADD) or attention deficit/hyperactivity disorder (ADHD). Then, when there is an obvious knockout from an auto accident or sports injury and the child complains of seeing stars, hearing bells ring, or having a severe headache, a diagnosis of concussion is finally made and rest is recommended. Because everyone thinks this is the child's first concussion, however, they are puzzled when the symptoms of fatigue, confusion, chronic headache, and light and noise sensitivity persist weeks after a seemingly minor incident. In truth, the majority of most first-known and diagnosed concussions have been preceded by numerous others that have gone unnoticed, again characterizing "the Silent Epidemic." This is why a child's concussion symptoms may persist. As mentioned previously, males between the ages of 16 and 24 have historically had a higher incidence of concussion than females, most through participation in regular and extreme sports, recreational activities, auto accidents, and military duty. One of the symptoms of concussion is aggressive behavior, which, along with the male hormone testosterone, causes more risk-taking and aggressive behavior that in turn can result in additional concussions from blows to the head. Some examples are skateboarding without a helmet, and getting into physical fights in which punches are thrown to the face or head. A recent trend is toward females in this age bracket also being diagnosed with multiple concussions by the age of 24 through athletic participation and blast injuries incurred during military duty. Statistics show a higher incidence of drinking among teens and young adults, as compared with adults (35 to 65) and seniors (65 and older). The resulting impaired thinking leads to an increase of sports, recreational, and automobile accidents. It is following these incidents that a concussion is likely to be reported; however, the injury is usually seen as an initial concussion rather than the latest in a series. As with younger athletes, prior concussions may have been dismissed or minimized, either purposefully or because the person truly doesn't remember having been knocked out. Or there may have been a misdiagnosis on a medical professional's part. Chapter 5 addresses the various methods for accurately diagnosing and assessing concussion. Please note that the above list does not include recreational activities that can cause concussion but often do not involve a visit to a doctor's office or hospital. Also, activities and the frequency of related injury may vary according to recreational trends, locale, and time of year. 1. Cycling 2. Boxing 3. Football 4. Wrestling 5. Baseball and softball 6. Basketball 7. Water sports, including diving, scuba diving, surfing, swimming, water polo, waterskiing, and water tubing 8. Powered recreational vehicles, including ATVs, dune buggies, go-carts, gas-powered scooters, minibikes, and dirt bikes 9. Soccer 10. Skateboards and nonpowered scooters 11. Fitness, exercise, and health club participation 12. Winter sports, including skiing, sledding, snowboarding, and snowmobiling 13. Horseback riding 14. Gymnastics, dance, and cheerleading 15. Karate 16. Golf 17. Roller and ice hockey 18. Tennis 19. Racquetball 20. Other unspecified ball sports 21. Trampolines 22. Rugby and lacrosse 23. Roller- and inline skating 24. Ice-skating THE ADULT YEARS By the age of 24, all of a person's myelin connections are formed and connected to the frontal lobe, allowing for clear thought and optimum control of behavior and emotions, which leads to decreased impulsivity and recklessness. Of course, major illness and one or more concussions can play havoc with this balance in behavior. Between 24 and 64 years of age, engagement in contact and competitive sports decreases while the pursuit of recreational sports remains about the same. Auto accidents and falls are fewer in this age bracket as well, with the exception of occupational mishaps and incidents of domestic violence. The incidence of first-time concussion is lower; but, as previously mentioned, the probability of such an injury actually being a first-time event is smaller than most people think. The chapters that follow will demonstrate the importance of considering not only the number of concussions a person has had, but also how often and how close together they occurred. These factors are very important to eventual recovery. After the age of 64, the frequency of concussion from sports, occupational, and blast injuries naturally decreases. However, people in this age group face a greater risk of concussion from auto accidents, falls, illness, elder abuse, assault, improper use of medication, and substance abuse. SECONDARY CAUSES OF CONCUSSION Along with focal and diffuse nerve damage and rotation and blast injuries, the neuroconnective damage that characterizes a concussion can also result from factors that may be deemed secondary causes. These include: Anoxia, or a lack of oxygen Bypass surgery Substance abuse Diabetes Lyme disease Contusion, or a bruise that can go undetected during conventional testing Edema, or swelling due to an accumulation of fluid in brain tissue Hematoma, a localized brain swelling due to an accumulation of blood from a break in a blood vessel Hemorrhage, or bleeding, in which a torn vessel releases blood into the brain tissue The symptoms of post concussion syndrome (PCS) from secondary causes are often not observed or treated, because the medical specialist's focus is on the specific disease, such as diabetes or Lyme disease. The emphasis in these cases is on regulating the body's sugar levels or treating the bacterial infection, not on how the disease causes dysregulation to the brain. No matter how careful one may be, there are circumstances and pastimes in life that carry the risk of concussion. It is certainly beneficial to be aware of the physical consequences of such an injury and to understand the signs and symptoms to look out for. Chapter 5 provides important information about steps to take when you suspect a concussion has occurred. CHAPTER 5 DIAGNOSING AND ASSESSING CONCUSSION/MILD TRAUMATIC BRAIN INJURY AND POST CONCUSSION SYNDROME (PCS) This book is devoted to the proper diagnosis and treatment of concussion (also known as mild traumatic brain injury , or mTBI) and post concussion syndrome (PCS), as well as the consequences of multiple concussions. If you are just beginning the process of recovery from a concussion, please realize that it is common to feel afraid and to feel, perhaps, that you are losing your mind. After all, time has passed since your injury, you look just fine, and your diagnostic tests have all yielded normal results. Yet, clearly, all is not well. It will likely take a sympathetic doctor's referral and a neuropsychological workup--a diagnostic process designed to reveal problems with reasoning, memory, and other brain functions--to finally pinpoint the source or sources of your difficulties. Once that is accomplished, you will almost certainly feel an overwhelming sense of relief that someone understands what you have been going through. This affirmation, along with support from medical professionals, friends, and family, can help to head off many of the debilitating psychological responses to a concussion. Overall, the outlook for recovery from a concussion is brightest with the early diagnosis and treatment of symptoms. Optimally, you can hope for slow, steady progress toward normalcy in the months after injury. If it is determined that long-term or permanent cognitive, physical, or emotional deficits exist, you can best help yourself by understanding the nature of your problems, acknowledging your limitations, and making necessary accommodations at home, school, and work. The following two chapters will provide you with information about assessment techniques and the most successful approaches to lingering problems that can follow a concussion. Chapter 1 explained how the brain is composed of vast interconnectivity networks similar to the telecommunications or airline networks. In those industries, when a major hub is disrupted, it can result in chaos and shutdown in many areas. The disruption of a major hub can come from a single event, such as a workman flipping a wrong switch that eventually causes a blackout across all of southern California, or it can stem from multiple events (the domino effect). In either case, it is extremely important to discover the source of the disruption in order to be able to fix it. This is also the case with a concussion, whether caused by an automobile accident, assault, or sports injury, since most people appear quite normal within hours of the impact. Thus, even if symptoms are observed by a coach, trainer, or physician, rest and relaxation is often the initial suggestion. It is only when new or lingering symptoms occur that a person may be compelled to seek additional medical assistance. As discussed in Chapter 4, a concussion may not be your first, and the continued cluster of symptoms that follow, called post concussion syndrome (or, in some parts of the world, post concussion disorder), must be correctly diagnosed for accurate and appropriate treatment to follow. In the past, such a definitive diagnosis was elusive. However, in recent years, both the understanding of the workings of the brain and the technology used in brain imaging have advanced greatly. Where before only major damage to the gray matter or vascular system could be seen, today minute and subtle structural injuries can be seen in both the gray and white matter as well as the vascular network. In addition, there have been diagnostic advances in the area of brain functioning, including specific tests for evaluating the ability to perform in sports. Excerpted from Coping with Concussion and Mild Traumatic Brain Injury: A Guide to Living with the Challenges Associated with Post Concussion Syndrome and Brain Trauma by Diane Roberts Stoler, Barbara Albers Hill All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher.