Bullet in the Head
It may be the title of your favorite Rage Against the Machine song, but it is also a grim reality in our society. Recently, the murder rate in many of our major cities has been on the decline. Yet, our 2nd Amendment rights preserve our “leadership” in the world in civilian gun violence. Even some of our smaller cities, like Compton in Los Angeles County, East Palo Alto, California, and even our capitol, Washington, D.C. have held the title of “Murder Capitol of the World” by having the highest annual number of murders per capita.
The “upside”(ha!) is that in times of “peace”, our military surgeons in training can go to our major trauma centers to get experience in treating “penetrating” trauma; experience they cannot otherwise obtain when there is no battlefield.
“Penetrating” trauma refers to gunshot and knife wounds. “Blunt” trauma refers to more common injuries like motor vehicle accidents and falls from heights. The distinct mechanical nature of these two types of injuries requires different treatment. Most severe trauma requires the expertise of specially trained surgeons who can find and control internal bleeding and resuscitate patients suffering from blood loss.
Gunshot wounds (GSW) to the head are sorrowfully on our minds with the news of the shootings of US Congresswoman, Gabriel Giffords, her staff, and others. Less newsworthy perhaps, but no less disturbing are the recent school shootings in Los Angeles during which a female student was struck in the head by a bullet fired, apparently by accident, from a gun carried in another student’s back pack.
My training as a neurosurgeon in Washington, DC and my work in Oakland, California in major “inner city” trauma centers gave me the opportunity to treat more than my fair share of penetrating head injuries. As I listened to the reporting on these two incidents, it occurred to me that most people had no idea what was going on regarding the treatment and conditions of our fellow citizens whose brains had been injured by projectiles from handguns.
Several things make GSW’s to the head different from striking one’s head on the windshield at 75 mph. The damaging energy transmitted through the head from hitting the windshield is distributed throughout the brain. On the other hand, “cavitation” is the problem with a bullet passing through the brain. Cavitation denotes the large column of damaging energy that surrounds the course of a much smaller missile traveling at a high velocity through solid matter. In fact, almost all GSW’s that cross the brain from the entry point to the opposite side of the head end in death. Naturally, high-velocity military grade weapons are even more devastating than the handguns that pollute our city streets. Even a “grazing” injury from an M16 can emit enough force through the brain to cause ultimate death.
Since the presence of a resting bullet in the brain seldom causes harm, removing the bullet is not the recommended surgical treatment and may result in more damage. The same is true of most bullets in the body and that is why a number of gunshot victims are walking around with bullets still inside. Instead, it is recommended for GSW’s to the head that the entry and exit points simply be debrided (“cleaned up”) and closed (“sewn up”). Bone fragments near the surface that can be easily removed should be, the dense covering of the brain, called the dura mater should be repaired to keep spinal fluid from leaking out, but anything more will not help the brain recover.
The similarity between penetrating and blunt brain trauma lies in the fact that destroyed brain cells cannot regenerate. While “stunned” brain cells, can recover function, there is no way to predict how much a person can improve after an injury. It takes generally 3 to 6 months to reach maximum improvement. Few treatments are available for brain injury and most of them have little effect on ultimate outcome.
Essentially nothing can be done about brain cells destroyed by the initial injury, so modern treatment focuses on salvaging those cells with the potential to recover. Another unique aspect of the brain that makes it more sensitive to the effects of trauma is that it is confined within a rigid box, the skull. All tissues swell when they are injured, but the brain has no room to swell. Instead, the pressure rises inside the head making it more difficult for blood to reach the brain; and if you think the normal brain is highly dependent on a continuous supply of oxygen and nutrients, then you might imagine that the injured brain is even more vulnerable to diminished blood flow.
Thus, the focus of acute brain injury treatment is on reducing the swelling or “intracranial pressure”, and maintaining enough blood supply to meet the demands of the healing tissue. A number of medical treatments is applied to these ends. The patient’s ventilator rate is increased to lower carbon dioxide (CO2) in the blood stream, which decreases the volume of blood vessels in the brain. Obviously, this must be done carefully to avoid restricting blood flow to the brain. Intravenous solutions of a drug called mannitol or highly concentrated salt solutions help reduce the swelling in the brain. The patient might also be placed in a “medical coma”, basically deep general anesthesia, for several days. This was done for Ms. Giffords. The idea is that if the brain is asleep, it need less oxygen and nutrients, and is thus less vulnerable if the blood flow is inadequate. In dire situations of brain swelling, one or both halves of the skull can be surgically removed temporarily to give the brain more room to swell until the swelling resolves on its own, which usually occurs by around one week after the injury.
Glaring absences occurred in the media reports about Ms. Gifford’s condition after her injury. It is what the doctors were not saying that concerned those of us “in the know”. The bullet reportedly struck “Gabby” in the left temple area and exited on the same side of her head more toward the forehead. The “good news” is that it did not cross through the center of the brain, which is typically fatal. The worst news is that the left temporal and frontal regions of the brain not only control movement on the right side of the body, in most of us they control our ability to speak and understand speech. So, while “being very strong on her left side” and “obeying simple commands” is better news than it might be, it does not reflect the true gravity of Ms. Gifford’s injuries.
Ms. Gifford was recently moved to a facility that will focus on her rehabilitation. She will receive intensive therapy from speech, occupational, and physical therapists, among other types of treatment. The goals will be to facilitate the recovery of use of her right arm and leg, and her ability to speak and understand speech. Sadly enough, full recovery of these functions is impossible. The entire country is hoping for the best for her. Our thoughts are with her and those injured or killed in the incident, and their families and loved ones.
by Thomas Chappell. MD