Approach to traumatic brain injury: Clinical sciences

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Introduction0:00–1:14

Traumatic brain injury, or TBI for short, is caused by a penetrating or blunt force to the head resulting in temporary or permanent impairment of brain function.
Common mechanisms of injury include direct head trauma from falls or being struck by an object, acceleration-deceleration or whiplash from motor vehicle crashes, or foreign body penetration like gunshot wounds.
The degree of injury ranges from mild to severe as classified by the Glasgow coma scale, or GCS. This scale measures eye-opening, verbal, and motor responses to stimuli on a scale from 3 to 15, with 3 representing a comatose state, and 15 being normal.
Traditionally, a GCS score of 13 to 15 represents mild TBI, 9 to 12 indicates moderate injury, and a score of 8 or below is considered to be severe.
Your first step in evaluating a patient presenting with TBI is to perform the primary survey by assessing their ABCDE. First, secure the Airway and consider endotracheal intubation or a surgical airway if the patient cannot protect or maintain their own airway.

Acute Management1:14–3:19

Be sure to immobilize the cervical spine and maintain immobilization during endotracheal intubation until cervical spine fracture has been ruled out.
Next, ensure adequate Breathing or ventilation. Then, assess Circulation and obtain 2 large bore IVs or IO access while continuously monitoring vitals.
Next, assess the patient’s Disability and neurologic status by calculating their GCS and assessing pupillary reflex. Keep in mind that the patient’s GCS can change rapidly.
Also, remember that a GCS of 8 means intubate if you haven’t already! Finally, Expose the patient and remove all clothing to assess for any other associated injuries, and then cover the patient with warm blankets to prevent hypothermia.Once these important steps are done, you can move on to a secondary survey, which includes history and physical exam.
Here are some important clinical pearls! First, if the patient is not lucid, family members, bystanders, or EMTs who brought them into the hospital might be able to give you important elements of history such as the mechanism of injury and when they lost consciousness.
Next, as part of your physical exam, perform a full neurologic examination. Finally, as you are doing your exam, keep in mind that even a mild head trauma can rapidly progress, so it’s important to be on your toes.Alright, let’s start with penetrating TBI.
History might reveal a gunshot or foreign body, like shrapnel, penetrating trauma with loss of consciousness, amnesia, post-traumatic seizures, headaches, nausea, or vomiting.

Penetrating TBI3:19–4:49

Upon examination, you’ll find an open wound with an exposed skull or brain matter. Neurologic exam shows altered mental status with GCS below 15 and dilated, unequal, non-responsive, or slowly reactive pupils with papilledema on ophthalmoscope.
You might also see focal neurologic deficits like sensory or motor deficits. Finally, if the patient is hypertensive, it could be from the Cushing reflex in response to high intracranial pressure.
So, consider a penetrating TBI and order a non-contrast CT of the head. Although imaging is not always needed, a CT can help you identify the foreign object and determine the extent of the injury including associated skull fractures, hematoma or intracranial bleeding, parenchymal edema, or even herniation.
With these findings, the diagnosis is penetrating TBI.Let’s move on to diffuse axonal injury. Patients typically present with blunt head trauma or acceleration-deceleration injury.

Diffuse axonal injury4:49–6:11

Additionally, history reveals a post-traumatic loss of consciousness, confusion, dizziness, seizures, headaches, nausea, and vomiting.
Examination might show signs of dysautonomia, such as diaphoresis, vasoplegia, hyperthermia, abnormal muscle tone, posturing, and labile vital signs.
Often, brainstem reflexes are intact but patients are in a comatose or vegetative state, so GCS is 3. These findings indicate severe diffuse parenchymal injury.
Next, get a CT or MRI of the brain. Imaging showing multiple, small, hyperdense, or attenuating punctate lesions along the gray-white matter junction, subcortical or deep white matter, corpus callosum, or brainstem confirms your diagnosis of diffuse axonal injury.
This condition is associated with poor prognosis.Moving on, let’s talk about intracranial hemorrhage, which can vary in severity from incidental and nonconsequential, to severe and imminently life-threatening.

Intracranial hemorrhage6:11–6:34

There are four main types: epidural, subdural, subarachnoid, and intraparenchymal bleeds.Epidural hematoma occurs with blunt trauma to the temporal bone, leading to fractures.

Epidural hematoma6:34–7:46

Because the middle meningeal artery is close to the temporal bone, sharp bone fragments or blunt trauma itself can injure it and cause bleeding into the epidural space.
It is more common in patients who are younger than 50 because, in older individuals, dura is firmly attached to the skull.
Typically, patients present with initial loss of consciousness, then a lucid period, after which their mental status deteriorates.
As the hematoma becomes larger, it presses on the oculomotor nerve, leading to ipsilateral pupil dilation on physical exam.
With these findings, suspect epidural hematoma and order a CT of the head. CT will show a biconvex hyperdense area between the brain and the skull.
Since dura is attached to the cranial sutures, epidural hematoma does not cross suture lines. So, if you see this, diagnose epidural hematoma.Now, subdural hematoma happens when the bridging veins within the subdural space are torn from blunt head trauma like a fall.

Subdural Hematoma7:46–8:55

Elderly patients and those with chronic alcohol use disorder may develop cerebral atrophy, leading to an increased space between the dural membrane and the cortical surface of the brain.
This in turn increases tension on bridging veins, making them more susceptible to subdural hematoma. Additionally, history will typically reveal a progressive loss of consciousness.If you suspect a subdural hematoma, obtain a CT of the head.
CT showing a classic crescent moon-shaped bleed in the subdural space that crosses the suture lines means that you are dealing with subdural hematoma.Here’s a clinical pearl!
A subdural hematoma can be acute or chronic. In acute ones, the bleeding is fresh, so it looks hyperdense on CT.
However, in the chronic one, bleeding becomes iso- or even hypodense.Next, subarachnoid hemorrhage might result from trauma, like a sudden acceleration-deceleration injury or severe head trauma.

Subarachnoid Hemorrhage8:55–9:50

Patients usually report severe headache, describing it as the worst one in their lives. Additionally, history might reveal photophobia and loss of consciousness.
As for the physical exam, you might find neck stiffness due to blood in the subarachnoid space. In this case, consider subarachnoid hemorrhage and order a CT of the head.
If you see hyperdense blood in the subarachnoid space and brain sulci and fissures, diagnose subarachnoid hemorrhage.Here’s another clinical pearl!
Next to trauma, an important cause of subarachnoid hemorrhage is the rupture of intracranial aneurysm! Lastly, intraparenchymal hemorrhage occurs when there is bleeding into the brain parenchyma.

Intraparenchymal Hemorrhage9:50–10:35

It is more common in patients who are on anticoagulation therapy. Intraparenchymal hemorrhage is seen more often with penetrating TBI but can occur in severe blunt head trauma as well.
History might reveal loss of consciousness, while the physical exam might show focal neurological deficit like hemiparesis.
With these findings, consider intraparenchymal hemorrhage and order a CT of the head. On CT, you’ll see a collection of blood in the brain parenchyma, which is enough to diagnose intraparenchymal hemorrhage.Okay, let’s talk about concussion or contusion.

Concussion or Contusion10:35–13:10

Concussion is the most common form of mild TBI especially in younger patients. Patients might report blunt head trauma from a fall, an object hitting their head, or collision injury from playing sports.
Additionally, history often reveals loss of consciousness, amnesia, confusion, post-traumatic seizures, headache, nausea, or vomiting.During the physical examination, you might find lethargy and altered mental status with normal pupils and no focal neurologic deficits.
If this is the case, consider a concussion and order a CT of the head. CT might show brain edema with a poorly demarcated contusion, which supports your diagnosis.
To clarify, concussion is a clinical diagnosis whereas a contusion is a radiologic finding and diagnosis. In reality, the two go hand in hand as a concussion is usually caused by a mild contusion, or bruising, of the brain but there may be no radiologic finding.
Another important fact to note is that not all patients with a concussion need a CT scan. It is often obtained for patients with moderate or severe signs and symptoms of concussion.Here’s a clinical pearl!
Recently, clinical tests for concussion have been used, called sideline tests, to assess sports injuries and the ability to go back to play and routine activities.
These include assessments of symptoms, balance, and normal functions like reading and memorizing. They can help triage patients who do or do not need to have limitations placed on activity.Okay, let’s end with a high-yield fact!
A special type of injury is called coup-contrecoup injury. Let’s say a head hits an object.
This accelerates the skull which hits the brain, causing the injury at the site of impact, known as coup injury. Now the brain and skull both travel in the same direction.
Once the skull stops, the brain inside is still traveling so it hits the skull on the opposite side of the injury. This is known as contrecoup injury.Alright, as a quick recap… Traumatic brain injury is commonly caused by blunt head trauma, penetrating injury, or an acceleration-deceleration mechanism.

Review13:10–13:30

Most patients with TBI should be assessed with a CT. As for your diagnoses, consider penetrating TBI, diffuse axonal injury,