Welcome back. In this and the next few lessons, we will be talking about specific injuries that can occur. You now have an understanding of what trauma is, the mechanics and energies involved, as well as some of the important considerations when dealing with a trauma patient. Now, what happens with specific traumatic injuries? We will cover trauma by organ system, isolating different parts of the body, and what injuries you should consider in these particular areas. Having an understanding of what injuries may be present can help you determine where your patient may need to go and how quickly you need to get them there. It will be helpful for each of these videos to renew the pertinent anatomy associated with the body system we are discussing. In this video, we will cover injuries to the head. Remember, the nervous system consists of the brain, cranial nerves, spinal cord, and spinal nerves. So, let's start at the top. The anatomy of the head includes the skull, the meninges, and the brain. The meninges are inside the skull and they are a layer that protects the surface of the brain. There are three layers, the dura mater, the arachnoid, and the pia mater. It is important that when you have an injury and possibly bleeding into the brain. The parts of the brain that are important include the cerebrum, the cerebellum, and the brain stem. Review your anatomy if needed. We will start with injuries that can occur to the outermost part of the head and work our way in. So, what's on the outside? That's right, the scalp. The scalp can be injured and just about any of the ways that we learned during the soft tissue injury section. Particularly, it can be lacerated, abraded, or avulsed. The scalp is a very very vascular part of the body, meaning there's a ton of blood supply to the scalp. So, a laceration to the scalp can in fact be life-threatening from bleeding. There can also be a hematoma or bleeding under the scalp that you may not see. The blood vessels in the scalp have a more difficult time constricting like other blood vessels, so they can bleed more significantly. You can have bleeding from your scalp or under the skin of your scalp. The next layer to discuss that can be injured is the skull. The skull is a bone and like any other bones in your body, it can be fractured. However, as you can imagine, a skull fracture can be a devastating injury because of its proximity to other important structures like the brain. There are different types of skull fractures. A linear skull fracture is as you would expect a line. It cannot be felt or palpated and it is diagnosed with advanced imaging in the hospital. A depressed skull fracture on the other hand is when the skull is indented towards the brain. You can usually feel this is your palpating the skull, and it can cause significant damage if the bone protrudes into the brain. A basilar skull fracture is a fracture that occurs to the base or the bottom portion of the skull. This can be concerning because it can cause CSF or cerebral spinal fluid to leak. If it is present, CSF appears from the nose or ears as a clear or slightly yellowish fluid. Because of the blood vessels that may be ruptured when these fractures occur, the patient may have blood coming from their ears, bruising around their eyes, or bruising behind their ears. As well as with all fractures, fractures of the skull may be open or closed. It's considered open if there is an open wound in the scalp that overlies the fracture and closed at the skin is intact. When there's trauma to the head, blood vessels can break. Where these blood vessels are located in relation to brain tissue in the meninges or dura, remember the coverings of the brain, are important in understanding the different types of what we call intracranial hemorrhage or bleeding in the brain. Any of these types of bleeding can be deadly within minutes. Remember, the brain tissue is in a rigid enclosed space. It's like a bottle. If you start bleeding a lot, there's not enough room for the blood in the brain and the skull, so it may start pushing on the brain. This can cause a phenomenon called herniation. Herniation is when brain tissue moves through the small area at the base of the skull called the foramen magnum. Think of it like the opening of the bottle. This movement can compress the brain stem, and the compression and movement quickly leads to death. Let's break down the different types of bleeding you can have in the brain. An epidural hematoma is as it sounds if you break the word down, outside of the dural or above the dural, epidural. This bleeding occurs between the dura mater and the skull. It usually involves the blood vessels that are outside the brain itself and is associated with a skull fracture. These patients may initially lose consciousness, then become conscious again, and then lose consciousness again. This in-between time when the patient is awake is called a lucid interval. If they follow this pattern, be concerned your patient may have an epidural hematoma. The next type of bleeding that can occur in the head with trauma is a subdural hematoma. This occurs beneath the dura, between the dura and the arachnoid. Normally, this type of bleeding is from a vein. So, it's often slower, and it could even be a slow chronic problem. However, if enough blood collects, it can start pushing on the brain and cause herniation. Subdural hematomas are the most common type of bleeding into the brain, and the older your patient the more likely they are to suffer from this kind of injury. These patients may or may not lose consciousness depending on the speed and amount of bleeding. Subarachnoid hemorrhage is bleeding that occurs beneath the arachnoid layer of the brain, but not in the brain tissue itself. The most common cause of subarachnoid bleeding is actually from rupture of an aneurysm or a blood vessel abnormality. You learned about this type of head bleed in course two. However, a patient may have this abnormality and never know it until they suffer a trauma and that blood vessel ruptures. These patients may or may not lose consciousness in this really, and often have a terrible headache. Finally, the brain tissue itself can bleed. This type of bleeding is essentially like a bruise to the brain tissue and is usually a small amount of blood from a blood vessel. However, depending on where in the brain it is, it can still be catastrophic because of the brain tissue that it affects. Now, let's discuss something much more common than bleeding into the brain, concussion. Many people think of concussions associated with sports. Think about the football player that takes a hard hit on the head or the soccer player who collides with another. A concussion can cause a wide range of symptoms. Usually, this happens when the brain moves in the skull, which can stretch, tear, or shear the brain tissue. Patients with a concussion can be mildly confused or completely unconscious on initial evaluation. However, they usually wake up after a few minutes at the most. The patient may have confusion, inability to recall the incident, or repeated questioning called perspiration. They may also have nausea and vomiting, and maybe agitated or aggressive. This leads us into discussing what the signs and symptoms of a patient that may clue you into the fact that they have a head injury, be it a concussion or bleeding into the brain. Let's review that now. What signs and symptoms may your patient have that could indicate a traumatic injury to the head? Well, first and foremost is their mental status. This sounds like what we just discussed with the signs and symptoms of concussion, but the brain responds in the same way to most injuries, and the changes can range from confusion to unconsciousness. The symptoms associated with head injury are headache, vision changes, nausea and vomiting, or neurologic deficits. Meaning they have numbness or the inability to move a part of their body. All of these things can indicate a head injury, and should clue you in that you need to transfer your patient to a hospital, and probably a trauma center depending on the rest of their situation. Now, what about the exam findings of a head injury? These patients may have unequal pupils, which is often a sign of impending herniation. As discussed with the basilar skull fracture, they may have bruising around their eyes or behind their ears. What about their vital signs? In severe brain bleeds, the patient may have abnormal respirations, and increased blood pressure, and a decreased heart rate. These three things together are known as cushing's triad. It is an indication of a severe head injury and possibly an impending herniation. Remember the combination of these findings: Head injury, severe hypertension, and bradycardia should always raise your concern. The other finding your patient may have is something called posturing. This is when the body has a somewhat involuntary response to painful stimuli. Flexion posturing known as decorticate posturing, the patients flex their arms across their chest. Extension posturing or decerebrate posturing is when they extend their arms and their legs. Both of these are considered non-purposeful responses to pain, and indicate a severe injury to the neurologic system. We will cover this more as we discussed the approach to examining in the treatment of the head injury patient in an upcoming video. Let's take a break. We will discuss the approach to the patient with a head injury shortly, but this is a lot of information to cover. Take a brain break, and we'll see you again soon.
