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About 70% of car accidents have some element of head injury, so it’s a common occurrence. It is estimated that there are probably 200 or 300 per 100,000 population that suffers some form of head injuries and there are about half-a-million new cases each year in the country. About 50,000 die from head injuries. The speed of the vehicle, the alcohol intake, whether the person has seat belt, those are factors that really affect the outcome from head injuries. Especially the seat belt does have a significant role in determining the outcome from head injury from a car accident.
There are several types of injuries that have been described. I am sure you have heard about concussion, which is essentially means that it’s irreversible. Contusion, where there is bruising of the brain and if it’s in the functional area, there may be neurological deficits. Then you have a diffuse accident injury, and what diffuse accidental injury means is just that there is diffuse injury to the brain.
Then the other types of injuries that occur is edema, which is usually secondary to the injury. They’re usually cytotoxic type of edema where the brain cells themselves are damaged, rather than fluid in the interstitial space. Then you can get polar injuries, which is injuries to different poles in the brain, like the frontal pole or the temporal pole. This slide just shows you why you get polar injuries because if you look at the inner surface of the skull there are bony ridges.
This is anatomy and physiology. The skull is a rigid structure which actually protects the brain from a lot of injury than it normally should. Unfortunately the skull also has bony ridges so in some ways the skull does contribute to injury. Of course we are not supposed to be going at high speeds.
Then we classify different structures. The scalp: you can have a contusion, laceration or a hematoma formation under the scalp. The laceration can bleed and the easiest way to stop is to just put sutures through. Put pressure, I suppose. Usually, except for the superficial temporal artery or the occipital artery.
Then you come to the skull, the bone which can have a linear fracture, which is not very important by itself. The only thing is, if you do have a linear fracture then you’ve got to watch the patient because there is a possibility that you may get epidural hematoma, for example.
This is a fracture going to the frontal sinus. You’ve got air in the head. This here, if you look at it carefully is a double density, so that’s a depressed skull fracture. Sometimes the depressed skull fracture is over a short segment and seen better on a plain film x-ray if you see a double density. You can miss it on the CT.
Then we come to the intracranial clots, not the intracerebral. You have epidural, acute subdural, chronic subdural and intracerebral. The epidural clots come from fracture or tear in the vessels, the artery or the vein. Either one of them usually this is more common than the artery. The artery is tougher to break.
This shows you an epidural clot and it has a lens-shaped appearance because it has to strip the dura of the skull, so there’s a limiting factor and so that’s why you see a lens-shaped. Then you come to acute subdural and they’re usually associated with cerebral contusion.
Chronic subdural hematomas: Acute subdural hematomas can become chronic of course. Usually when a hematoma occurs in a patient that has just torn a little bridging vessel and there’s a lot of space in the head - like someone who’s got cerebral atrophy, because they got old, or they are very young and the brain.
Then we come to foreign bodies. This is the type of foreign body we usually don’t see over here, but can occur.
Evaluation and airway is the most important thing because once you get head injury and you get damaged brain, no one can fix brain. But you can certainly prevent further injury and so it’s important to make sure the airway is good, good perfusion, the blood pressure is okay. So it makes you treat shock. Then you go to the neuro exam.
This is just a slide showing the Glasgow Coma Scale and I hate it because you can have Glasgow Coma Scale of 1, 1, 1, 3 and you can be dead, so it doesn’t mean a thing. But some people use it because some people like rigid criteria, you know. "Who do you intubate? Which patient do you put ICP?"
Then there is this thing that you probably see a lot of, chronic problems. Especially post-concussion syndrome. What is post-concussion syndrome? It all depends. Essentially post-concussion syndrome means the patient had a head injury and now has some symptoms. The symptoms can be difficulty to concentrate, headaches, dizziness, those kinds of symptoms. Nothing definite. Some people also tell you they have problems with memory. How do you handle it? Number one, if the patient had the symptoms before they were dismissed, before they saw their lawyers, then it’s probably true. If they’ve seen it afterwards, a week later, then they come back and give you symptoms, then it’s probably not real. So that’s a good rule. So what can you do for them? I suppose, what I do is to get a scan.