Severe Brain Injuries Deserve Intense Study

by Guy McKhann, M.D.

October 10, 2007

I am a neurologist, so I spend time worrying about people’s brains. I guess I could focus on other “common” organs, such as the heart or the liver. But to me, those are just pieces of meat; the brain is special. Thus I am concerned about the situations in which the brain will be damaged—situations which are included in the generic term “traumatic brain injury,” or TBI.

In civilian life, head injuries are common in automobile accidents and falls, but athletic injuries lead the list of causes (see “A Chill Down the Spine,” Los Angeles Times). In recent months there has been increased focus on both the frequency and longterm effects of concussions in football players—a welcome shift away from the attitude that “having your bell rung” is just part of the game. This is also a move away from the ridiculous idea that just because a man is a big, well-trained athlete, somehow his brain is more resistant to injury or to the effects of repeated injuries.

Brain injuries are not limited to males, either. With the increasing participation of women in sports such as soccer and gymnastics, aftereffects such as headaches, poor concentration and lack of motivation are being recognized.

One of the characteristics of athletes, particularly younger participants, is that they deny symptoms and plan to compete even if they have their heads under their arms. Investigators at the University of Illinois are trying to estimate the forces involved in football injuries, as well as the consequences (“High School Footballers Wearing Special Helmets to Monitor Brain Injuries,” News Bureau, University of Illinois at Urbana-Champaign).

This is an interesting clinical experiment. One doesn’t know when a fall or auto accident may occur. But in certain contact sports, like football or boxing, it isn’t a question of “if” but of “when.” Furthermore, these investigators perform tests of cognition at the beginning of the season, and then can compare that baseline with performances after head injuries. Their intent is to obtain information about what really happens to the brain during impact and subsequent recovery.

The situation in the military is quite different. There is probably no civilian equivalent to the blast injuries that are occurring in Iraq. As mentioned in the USA Today article “Scientists: Brain Injuries from War Worse Than Thought,” traumatic brain injury is the “signature wound” of the Iraq war. A high percentage of these injuries are from roadside bombs, which release blasts of pressure.

Most civilian brain injuries occur because the moving brain slams against its covering box, the skull, as occurs in a car crash. A blast injury is different. First, a wave of pressure hits the body. Ear drums may burst, and hollow organs, such as the bowel, may rupture. The brain sustains damage to deeper structures, setting up a continuing cycle of brain cell death.

The clinical symptoms may be progressive, involving continuing problems with memory, mood, and concentration. The effects may be cumulative, that is, repeated exposure to blasts may cause increasing damage to the brain. No one knows what the threshold should be. If a soldier is exposed to a significant blast, what should be done? Should doctors act as if the injury were a typical concussion and rest the soldier until he or she returns to normal? What about a second or third exposure?

For those studying head injuries, this is a whole new ballgame. Animal models are being developed, the pathology is being determined and a number of drugs are being tried to stop the progression of injury. Perhaps the research in football helmets described above can be adapted to soldiers’ helmets, so that the amount of force one is exposed to can be monitored.

Military medicine has made remarkable improvements in saving lives. Now it is time to pay more attention to the surviving brain. We must not ignore the longer-term effects of traumatic brain injury. They are real, not imaginary.

We are going to be seeing an increasing number of young men and women who have had their brains scrambled in Iraq. We need to learn how to asses the damage, how to quantify the symptoms, and how to treat these persons both acutely and over the longer term. This is both a medical and moral obligation.

Guy McKhann, M.D., is professor of neurology and neuroscience at the Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore. He serves as scientific consultant for the Dana Foundation and scientific advisor for Brain in the News.