Brain Injuries Are Much More Common Than You Might Think

Brain Injuries Are Much More Common Than You Might Think

The link between football and Chronic Traumatic Encephalopathy (CTE) – recently admitted to by the NFL – has been has been well established for years, and a prevalent topic in the media of late. Many football players suffer hundreds or even thousands of concussions and sub-concussions by the time they conclude their professional careers. That professional football players are extremely likely to develop brain disorders (with estimates as high as 97% in all positions excepting kickers) is thus somewhat unsurprising, and the sheer number of concussions they receive might make it seem unlikely that just one or even a few concussions could cause serious brain injury.

Even One Concussion Can Cause Devastating Brain Dysfunction

It is true that a single concussion is unlikely to cause any long-term problems. In fact, numerous studies have shown that around 80-90% of people who suffer a concussion will have no post-concussive symptoms three months later. Studies led by the Centers for Disease Control, the National Institutes of Health, the World Health Organization, and many others demonstrate, however, that the other 10-20% who suffer even one concussion will have devastating symptoms out to six months, one year, and beyond. Some studies have found that there are Vietnam veterans continuing to suffer from concussions they sustained in their service to this day. These post-concussive symptoms can include impairments in memory and cognitive functioning, as well as personality changes and severe anxiety and depression. Studies have also shown that concussions are strongly linked to increased risk of suicide and the development of neurodegenerative diseases such as Alzheimer’s and ALS later in life. It has been scientifically proven that concussions are, for many people, far more serious than is generally believed by the public.

The Problem With The Word “Concussion”

Brain scientists are now largely in agreement that the word “concussion” should be abandoned by the medical profession. They argue that, not only is “concussion” associated with a minor injury that has no serious medical consequences, but the word itself is ill-defined and confusing. Concussions, in medical terminology, are in fact just one type of Traumatic Brain Injury (TBI). Concussions fall into the category of Mild Traumatic Brain Injuries (mTBI) – ones in which a blow to the head or a whiplash injury results in an “alteration of consciousness” (typically a state of confusion following a head injury), or loss of consciousness for 30 minutes or less.

A diagnosis of “concussion” after a patient is knocked unconscious for 30 minutes might lead him to believe that the injury was not serious and that he will have no long-term symptoms; especially after he is cleared by a CT scan of his head at the hospital – a scan that, in fact, is incapable of demonstrating the presence of a Mild Traumatic Brain Injury. What’s more, studies have found that emergency rooms in the U.S. fail to diagnose as many as 55% of Mild Traumatic Brain Injuries.

How Mild Traumatic Brain Injuries Cause Devastating Symptoms

Brain scientists have noted that the most common type of injury, and the most likely to occur with an mTBI, is known as Diffuse Axonal Injury, or DAI. DAI occurs when, as a result of a blow to the head or a whiplash injury, the brain is “rattled” against the inside of the skull. As the brain is bounced against the skull, different parts of the brain slide over one another. When this happens, the axons connecting various neurons (brain cells) can be pulled and broken, or “sheared.” When axons are sheared, three important things happen: (1) the neurons that those axons connect die, (2) the connection between those neurons (which could be important to any number of brain functions such as memory, cognition, executive function, and motor function) is lost, (3) a flood of chemicals known as neurotransmitters is released. This all serves to highlight the unpredictable nature of an mTBI, in that:

  1. The release of neurotransmitters, if it is significant enough, can and does result in anxiety, depression, and aggressive behavior
  2. Neurons and axons are “highly oriented,” meaning that they serve specific functions that are unique to each brain, and that a wide range of symptoms can result from axonal shearing
  3. Not only are the consequences of DAI impossible to accurately predict, the presence of the injury itself is almost always impossible to detect on brain scans like CT and MRI. Some newly developed imaging techniques have shown promise in detecting DAI – however, those imaging techniques are expensive and largely experimental.

Each mTBI Increases The Risk of Long-Term Symptoms

While, as noted above, only about 10-20% of people who suffer an mTBI will have symptoms beyond three months, that 10-20% risk is cumulative. That is, each time a person sustains an mTBI, her risk of having long-term, devastating symptoms goes up. That is because, when axonal connections are lost, other axons attempt to “make up for” the lost connections – and, typically, they do within a few months. With each subsequent mTBI, however, more and more connections are lost and more neurons die, making it increasingly difficult for the remaining neurons to catch up.

The Likelihood of mTBI

The CDC has reported that roughly 1.5 million Americans suffer a Traumatic Brain Injury each year – 75 percent of those are mTBI. It is worth noting again that hospitals in the US have been reported to miss more than half of mTBIs in the emergency room – making the CDC’s report likely to be an underestimation of the true incidence. Considering the potentially devastating consequences of mTBI, and the substantial likelihood of sustaining them, it is no surprise that research into the treatment of mTBI and the prevention of the symptoms that can result is widespread, well funded, and ongoing.

What to do after an mTBI

For the time being, however, the best steps that one can take following a blow to the head or whiplash injury are to:

  1. Visit an emergency room right away, if only to rule out the possibility of an injury that requires immediate medical intervention such as a subdural hematoma
  2. Follow up with a doctor if symptoms such as confusion, ringing in the ears, anxiety, depression, anger, and memory problems do not resolve within a few days following an mTBI
  3. If problems persist, visit a neurologist or neuropsychologist for a thorough evaluation and treatment options such as medication and neurocognitive rehabilitation.