What is Brain Trauma?

A traumatic brain injury is any injury sustained to the head that disrupts the functions of the brain. A mild form of brain trauma, such as a concussion, results in a temporary disruption of mental stability and may bring about a brief period of disorientation, dizziness, or loss of consciousness. Much more severe cases of brain trauma can result in extended periods of unconsciousness. Depending on the extent of the injury, a victim may lapse into a coma for days, months, or longer. Even after regaining consciousness, people who have experienced severe brain trauma may suffer from other long-term problems such as amnesia—the partial or complete loss of memory. Many find their cognitive and motor functions are impaired— they may be unable to communicate or think coherently, and the body’s normal reactions to stimuli may be confused.

“A tap on the head, and anything can go wrong,” says author and social worker Michael Paul Mason, who assists survivors of brain trauma:

Anything usually does go wrong. You may not remember how to swallow. Or you may look at food and perspire instead of salivate, or salivate when you hear your favorite song. You may not know your name, or you may think you’re someone different every hour. Everyone you know and will ever know could become a stranger, including the face in the mirror. ⁷

Doctors classify brain trauma in two categories: closed head injuries and open head injuries. As the names suggest, a closed head injury involves trauma in which the skull remains intact, while an open head injury involves a direct and forceful impact on the skull hard enough to break it open. Certainly, open head injuries are regarded as extremely serious, but closed head injuries can also be devastating.

Closed Head Injuries

The brain is the body’s most complicated organ. Its tissue is composed of billions of cells that work in concert to enable people to think, learn, speak, see, take steps, manipulate eating utensils and tools, and carry out hundreds of other functions. When the brain is damaged, it may no longer be able to provide the rest of the body with the instructions to perform even the simplest of tasks.

Several significant anatomical features have evolved to protect this most complex vital organ against injury. The most obvious is the bony skull that encases the brain; the average adult skull is from 6.5 to 7.1 millimeters thick, or a little more than a quarter-inch thick. Inside the skull, the brain is surrounded by the meninges—three layers of tissue and fluid that act as padding. The skull and meninges are tough and resilient, but they can’t ensure absolute protection. They can’t stop a bullet or glass shard from penetrating the brain. A significant blow to the head can cause a skull fracture. Even a fall off a bicycle can damage these protective layers and the brain within.

Brain cells, or neurons, communicate with one another through structures called axons and dendrites. The axon is a fiber that extends from the nucleus of the cell; it splits into a network of smaller fibers known as dendrites. The dendrites from one neuron do not quite connect to the dendrites of the next neuron; there is a tiny gap, or synapse, that is bridged by electrical impulses. When the head sustains a blow, parts of the brain may shift inside the skull while other parts remain stable. This movement tears, stretches, and twists the axons and dendrites. “Imagine that you have an electric cable made up of individual wires,” says Lance Trexler, director of rehabilitation neuropsychology at the Rehabilitation Hospital of Indiana. “If you hit that cable with a hammer, the wires would break.” ⁸

Those twisted and damaged axons and dendrites—a sort of biological “faulty wiring”—cause a brain trauma patient to exhibit a variety of symptoms, including blurry or double vision, difficulty concentrating, inability to swallow, dizziness, headache, poor coordination, lightheadedness, loss of balance, loss of memory, muscle stiffness or spasms, seizures, slurred or slow speech, tingling or numbness, pain, a sense of spinning known as vertigo, and muscle weakness in the limbs or other parts of the body.

Brain trauma patients typically experience these symptoms soon after the mishap that caused their injuries. If the injury occurs during a traffic accident or other public incident, the patient may be transported to a hospital emergency room. In such circumstances, paramedics, physicians, and nurses are trained to look for brain trauma symptoms immediately. However, if the mishap occurs at home, the victim may just shake off the injury, thinking it is not serious. Other, delayed symptoms may show up days or weeks later, including anxiety or nervousness, behavioral changes, depression, and insomnia.

Ignoring the Symptoms

The danger of ignoring the immediate symptoms of brain trauma is that, though it may not be obvious at first, severe damage may have occurred. Blood vessels in the brain can rupture, causing bleeding in the brain. That will make the brain tissue swell, building up pressure inside the skull. When the brain is under pressure, the supply of oxygen to the neurons may be cut off, killing brain cells. Also, the pressure may force the brain downward, destroying cells at the base of the brain.

Grading Concussions

Some sports-related concussions are more serious than others. To guide doctors who treat athletes, the American Academy of Neurology has categorized concussions as Grade 1 (minor), Grade 2 (moderate), and Grade 3 (severe).

In a Grade 1 concussion there is no loss of consciousness, but the athlete displays a degree of confusion that lasts less than fifteen minutes. Athletes who sustain Grade 1 concussions can return to the field, but if they suffer a second Grade 1 concussion during the game, they are typically pulled out of competition and benched until they have been symptom-free for a week.

In a Grade 2 concussion, there is no loss of consciousness, but the athlete displays confusion for more than fifteen minutes. Athletes who suffer a Grade 2 concussion are routinely taken out of the game and benched until they have been symptom-free for a week. If their symptoms persist for more than a week, they often undergo further tests.

In a Grade 3 concussion, the athlete has suffered a loss of consciousness. Grade 3 patients are taken out of the game and benched until symptom-free for a week if their unconsciousness spanned a few seconds, longer if they were out for a few minutes. If tests show brain swelling or other symptoms, the athlete commonly is benched for the season and urged to give up contact sports.

You would think that people would naturally seek medical treatment for severe headaches, dizziness, double vision, and the other symptoms of brain trauma, but ignoring such symptoms is actually quite common, especially in contact sports. For example, Willie Baun, a Manchester, Massachusetts, seventh-grader, took what seemed to be an ordinary hit while playing football. Feeling woozy, he came out of the game. Baun sat on the bench for two games, then played again—even though he was still experiencing headaches. During his first game back with the team, he sustained another blow to the head. Doctors later diagnosed both blows as concussions.

After a concussion, calcium builds up in brain cells as they chemically react to the trauma. Calcium is an essential mineral in the human body, a main part of the structure of bones and teeth. It can also be found in neurons, where it is a vital part of the electrical activity that transmits signals from neuron to neuron. However, a calcium buildup in the neurons can be toxic to the brain cells. When there is too much calcium in the brain cells, the neurons stop working properly. If the patient rests and avoids further trauma, his or her brain cells can eventually rid themselves of their excess calcium through the normal process of electrical transmission. But if the neurons undergo further trauma before they have recovered, there can be an even further buildup of calcium.

Studies have shown that people who have received one concussion are more likely to sustain a concussion in the future. Even when the symptoms of concussion have completely resolved between injuries, people who receive a series of minor head blows over time—such as boxers, football and hockey players, and young athletes—risk developing repetitive head injury syndrome, the slow decline of cognitive abilities.

The risk of serious impairment goes up if a person suffers a second concussion before the brain has recovered from an initial concussion. In rare cases, even a mild second concussion can cause rapid, out-of-control brain swelling, a life-threatening condition known as second-impact syndrome, or SIS. Half of SIS cases are fatal, and those who have survived SIS are severely disabled.

Though Willie Baun fortunately did not develop SIS, he suffered temporary amnesia—he had trouble recognizing his parents and friends, and could read and do math on a second- grade level only. It took eight months before Baun’s symptoms cleared up and he was able to perform again at a middle school level. Looking back, Baun says he was wrong to ignore the symptoms of his concussion. “Even people who know my story think it can’t happen to them,” he says. “They have to be honest with doctors and parents that maybe they’re having symptoms. Maybe they’re not all right.” ⁹

Blood Clots on the Brain

The concussion is the most common form of TBI. Of the 1.5 million cases of brain trauma that occur each year, about 75 percent are diagnosed as concussions. Simply a bruise to the brain, a concussion might involve a brief period of headache, nausea, fatigue, confusion, sleep disturbance, and memory lapses before the patient recovers. However, some patients continue to experience symptoms for several days or weeks before returning to normal. As the cases of Andre Waters and Willie Baun prove, more than one concussion can lead to more severe, long-term consequences.

There are many forms of closed head trauma that are far more serious than a concussion. Among them are an infarction, which is also known as a stroke. An infarction occurs when blood is cut off to the brain, preventing oxygen from reaching brain cells. Most strokes are suffered by elderly people or patients with heart conditions that cause a reduction in blood flow through the brain. However, TBI can also cause infarctions by compressing a blood vessel in the brain, cutting off vital blood supply. Depending on where in the brain it occurs, stroke can cause varying degrees of paralysis or speech and memory impairment, and a major stroke can rapidly lead to coma or death.

A blow to the head also could cause internal bleeding. This condition is known as a hemorrhage—bleeding in the brain that occurs when blood leaks from a damaged vessel. In most cases, bleeding occurs within minutes of the injury, but sometimes it may not start for several hours. The consequences of a brain hemorrhage are like those of a stroke.

Another form of bleeding caused by TBI is known as a subdural hematoma—bleeding inside the skull but not actually in the brain. Subdural hematomas increase pressure inside the skull to often dangerous levels. Also, when cranial bleeding dries it forms what is known as a clot, which is a mass of hardened blood. The clot itself exerts pressure on the sensitive brain tissue. Hematomas and clots can block blood vessels, leading to stroke, or damage brain cells by their own pressure, leading to permanent impairment of brain function.

That is what happened to lightweight boxing champ Leavander Johnson, who took a tremendous beating from his opponent while defending his title in a September 2005 nationally televised match. Johnson stayed on his feet despite punches to his head, but the referee finally stopped the fight in the eleventh round. Johnson returned to his dressing room under his own power, then complained of a headache and collapsed. Doctors diagnosed a cranial hematoma and clot; Johnson underwent emergency surgery to remove the clot and relieve the pressure inside his skull, but the damage was too severe. In a coma, his condition deteriorated and he died five days later after his family agreed to remove life support.

The Glasgow Coma Scale

When a brain injury patient arrives in the emergency room, a doctor will attempt to assess the degree of the trauma by asking the patient several questions, such as “What is your name?” and “What day is it?” and by asking the patient to perform a series of simple movements, such as wiggling toes or opening and closing eyes. The doctor pays close attention to the patient’s responses, rating the person’s consciousness on a commonly accepted numeric scale known as the Glasgow Coma Scale, or GCS.

For example, the patient’s ability to open his or her eyes is ranked from 1 to 4. A score of 4 means the patient spontaneously opens his or her eyes; opening the eyes in response to painful stimuli is scored as 2; no response at all is scored as 1. Similar assessments are made for verbal responses (on a scale of 1 to 5) and motor responses (on a scale of 1 to 6). If, for example, the patient can converse clearly and spontaneously, the doctor rates the patient a 5 on the verbal scale; if the patient replies with incomprehensible sounds, the doctor will give the patient a 2. If no response is given, the doctor will grade the patient with a 1.

Obviously, the patients who score the lowest on the GCS are suffering from the most severe forms of brain injury and are in need of immediate medical attention, such as surgery. A total score of 8 or below (out of a possible 15) indicates the patient is in a coma.

Observers believe Johnson may have survived had he not been so willing to take punishment in what was obviously a losing battle in the ring. “This kid’s courage was his downfall,” ¹⁰ said boxing promoter Lou DiBella.

Soon after Johnson’s death another boxer, heavyweight Joe Mesi, suffered a hematoma that kept him out of boxing for two years. Against the advice of doctors and fight experts, Mesi elected to fight again. Said boxing analyst Teddy Atlas, “I’m scared, that’s all I can say. Something of his brain has been compromised.” ¹¹

Open Head Injuries

Blows to the head like those sustained by Johnson and Mesi are serious, but the most severe brain injury occurs when a foreign object—a bullet, shrapnel from a bomb, or debris from a construction site—pierces the skull and lodges in the brain, causing an open head injury. In such cases, the patient not only suffers damage to brain cells, nerve fibers, and blood vessels but also is at high risk of developing a brain infection. Exposure to bacteria or other contamination can lead to many kinds of infection, with complications that can potentially increase brain swelling, delay recovery, and worsen the damaging effects of the injury. For instance, if a skull fracture involves tearing of the meninges, a potentially fatal infection known as meningitis can develop. Says Michael Paul Mason, “Open head injuries are a frightening mess, literally. Whether the insult comes from a bullet, a baseball bat, or a high-speed collision, the result is always chaotic and distressing. The scalp is so vascular [contains so many blood vessels] that blood pours liberally from any laceration. When bone is cracked or penetrated, shards invariably get lodged in the brain.” ¹²

Scanning the Brain for Trauma

When patients are brought to the emergency room with open head TBI, doctors can usually quickly determine the extent of the injury, and take the necessary steps to stabilize the wound and prepare the injured person for surgery. In the case of a suspected closed head TBI, physicians may have to do some detective work to diagnose the trauma.

First, vital signs—blood pressure, pulse, body temperature, and ability to breathe—will be checked and stabilized. Next, the doctor will ask the patient a series of questions that could indicate impaired cognitive abilities: What’s your name? Where are you? What day is it? The doctor may ask the patient to perform simple tasks, such as wiggling toes or holding up fingers. The doctor will ask the patient to open and close his or her eyes, move limbs, and speak.

While in the emergency room, the doctor may be able to make a quick assessment of the pressure on the brain by using an ophthalmoscope, an instrument that allows doctors to look at the back of the eyes for evidence that the brain is under pressure. After the initial examination in the emergency room, the doctor may order other tests and scans.

The doctor will likely order an X-ray screening of the patient’s skull. X-raying an injury is one of the most routine of all medical examinations, and physicians have used this technology for more than a century. X-ray scans are used to diagnose trauma to all bones, not just the skull. When shot through the human body, X-rays pass easily through soft objects such as skin and internal organs but are absorbed by bone and metal. In the hospital, the technician will record the X-rays on photographic film placed behind the traumatized body part. The whole process, from photographing to processing the film, can be accomplished in a few minutes.

X-rays are useful for detecting trauma to the skull but they do not give doctors a very clear picture of brain injuries— unless there is a foreign object such as a bullet or shard of glass lodged in the brain. However, whether or not the X-ray scan shows a skull fracture, if the doctor suspects that the brain has also sustained trauma, he or she will probably order additional examinations.

One of those is likely to be the computed tomography scan, or CT scan. The examination is also sometimes known as a computed axial tomography scan, or CAT scan. CT scans employ X-rays, but the screening is regarded as far more thorough than a simple X-ray image. A basic X-ray image gives the doctor a two-dimensional picture of the injury. During a CT scan, the patient lies inside a doughnut-shaped machine that employs special photographic equipment to encircle the body. As the X-rays enter the body from all angles, different tissues absorb different amounts of X-ray radiation. The CT scanner measures the radiation, converting it into electrical impulses. A computer then uses the electrical impulses to create a three-dimensional image of the injury that is displayed on a monitor. According to the American Association of Neurological Surgeons:

A computed tomography scan (CT or CAT scan) is the gold standard for the radiological assessment of a TBI patient. A CT scan is easy to perform and is an excellent test for detecting the presence of blood and fractures, which are the most crucial [injuries] to identify in medical trauma cases. Plain X-rays of the skull are recommended by some as a way to evaluate patients with only mild neurological dysfunction. However, most centers in the United States have readily available CT scanning, which is a more accurate test. ¹³

Another technology that is often employed to detect brain trauma is magnetic resonance imaging, or MRI. As with a CT scan, the MRI patient lies on a table inside a machine shaped like a doughnut. The MRI doughnut is actually a huge magnet that energizes certain atoms in human cells. During the screening procedure, the scanner broadcasts radio waves through the body that strike the energized cells and are translated into an image. An MRI scan can reveal far more about soft tissue than either an X-ray or CT scan can; therefore, MRI is regarded as a very valuable tool for detecting brain trauma. A drawback of the MRI scan is that it may take up to an hour or more to produce a series of images—much longer than X-rays or CT scans, which is why MRI scans are not typically used in emergency situations.

Another diagnostic test that is often used in nonemergency situations is the electroencephalogram, or EEG. The purpose of the EEG is to detect the amount of electrical activity in the brain, which drives the impulses transmitted by the axons and dendrites. In preparation for an EEG, up to twenty-five adhesive metal disks are placed on the patient’s skull. These disks are electrodes, which are connected by wires to the EEG machine. The electrodes transmit the electrical activity in the brain into the EEG machine, which displays the brain’s activity in the form of wavy lines that appear on a monitor. If brain trauma exists, the EEG may be able to pick up the region of the brain where the electrical activity has been interrupted by the injury. It can take two hours or more to perform an EEG test, which is why doctors may not order an EEG if the patient is in need of immediate treatment.

Before the development of CT and MRI technology in the 1970s, physicians often relied on angiograms to detect trauma to blood vessels inside the brain. When an angiogram is per- formed, a dye is first injected into the patient’s bloodstream. X-rays are then shot through the traumatized region of the head to detect leaks in blood vessels, which are highlighted by the dye. CT and MRI scans do a very good job of detecting trauma to blood vessels in the brain. However, angiograms may still be employed by the doctor to detect a tear, which is known as a dissection, in the carotid artery, which is located in the neck and supplies blood to the brain. A tear in the carotid artery can lead to a stroke.

If brain swelling is a concern, the doctor may order intracranial pressure, or ICP, monitoring. During ICP monitoring, a plastic tube is inserted into the brain through the skull via a hole drilled by a surgeon. The tube senses the pressure inside the skull and transmits measurements to a recording device. If necessary, the tube can also be used to draw out fluid and relieve pressure on brain tissue. This form of monitoring is usually reserved for critical trauma cases; typically, the patient is already unconscious when the physician makes the decision to drill through the skull.

Profound Impacts

Medical science has done a very good job of finding ways to detect TBI. If the trauma is mild, such as a concussion, chances are the condition will clear up on its own without further complications. Other cases, which may involve bleeding in the brain or trauma that results in open head wounds, are obviously far more serious and can have devastating consequences, such as amnesia, stroke, and cognitive impairments.