It has been four days now and the news cycle has spun away from the American Flight 311 crash just short of the Caribbean Sea in Jamaica. Even Google can’t seem to find anything current. One might thus assume that no one was seriously hurt and it was a Christmas miracle. We hope so. But what we know about concussion makes us pause.
Brain injury is a process not an event. Those words were probably first published by noted brain researcher, Thomas Gennarelli, M.D., probably in Greenfield’s Neuropathology. It is a theme I understood early in my career and have written about, advocated about and preached about since. I have a series of web pages devoted to it beginning with http://subtlebraininjury.com/tbiprocess1.html To simplify a very complicated neuropathological phenomenon, several different pathologies can make brain injury more significant at 24 or 48 hours than they are at the two to four hour time window when injured people are often seen in the Emergency Room.
One, the brain may swell or bleed, cutting off internal circulation to the blood vessels within the brain, causing secondary brain damage and even death. This is what happened to Natasha Richardson after her skiing accident.
Two, more likely in a concussion case, the initial injury to the axon in a shearing mechanism, will open up a defect in the insulation around the axon, allowing toxic where they don’t belong neurochemicals to attack the axon. Over next 72 hours, an injured but functioning axon may suffer additional injury. Over time that axon may die. While the brain has millions of axons and no single axon is critical for survival, when enough axons die in a given area, the brain’s internal communication abilities can become compromised. Now processing speed and the way in which the attention centers and the emotional centers of the brain are interconnected may be compromised.
While seeing the damage to any given axon is impossible short of an autopsy, the effect of the progress of brain damage can be measured, if the physician or other health care professionals ask the right questions in the week after injury. The brain that is likely to be permanently changed by a concussion, is the brain that isn’t working efficiently in those first few days. The best way to tell? Ask questions to determine whether there is amnesia for events after the injury. If the person doesn’t remember what happened yesterday, they must be given a much higher priority for brain injury evaluation and treatment.