Traumatic Brain Injury (TBI)

00:01 Welcome back.

00:02 Thanks for joining me on this discussion of traumatic brain injury under the section of trauma.

00:08 Let’s start with a clinical scenario.

00:10 Take a look at this picture.

00:12 The driver, a 25-year-old man, sustained a high-speed roll-over motor vehicle accident who now arrives in your trauma bay, is not responsive.

00:22 Do you know what to do next? I’ll give you a second to think about it.

00:28 Remember, back to our previous initial assessment and management discussion, always begin with the ABCs.

00:35 Now that you’ve ascertained an intact airway, a breathing patient and a patient who has intact circulation, we move to the D of disability where we ascertain a Glasgow Coma Scale.

00:46 The Glasgow Coma Scale has three components.

00:49 It’s a global assessment of the patient’s neurological status.

00:53 Take a look at this table.

00:55 You’ll notice that there are columns for eye, verbal, and motor examinations.

01:00 The coordinated effort of the patient who is able to open their eyes, speak to you, and move their extremities is one that is an oriented patient.

01:10 Glasgow Coma Scales are scored from a minimum of 1 to a maximum of 6 points.

01:16 We assign the best exam finding.

01:19 Remember, the best exam finding.

01:22 When presented on an examination of what is the GCS score, always look for the best exam finding.

01:28 The eye exam is listed from 1 to 4.

01:31 The verbal examination is listed from 1 to 5.

01:34 And the motor exam is listed from 1 to 6.

01:38 There is no precedence or importance of one exam over another, although it appears that motor is heavily weighted.

01:46 Important to remember that you just have to spend a few minutes looking at the slide and memorizing.

01:51 Unfortunately, I don’t have any simple ways of memorizing the GCS EVM scoring.

02:00 The patient does not open his eyes, respond verbally or move.

02:06 My question to you is, “What is this patient’s Glasgow Coma Scale?” Again, the patient doesn’t open eyes, has absolutely no verbal and is not moving at all.

02:19 This is a common trick question.

02:21 The minimum GCS is 3 because the lowest score is 1 on a 1 to 6 scale.

02:27 So, the minimum score GCS is 3 in this completely comatose patient.

02:33 As a side note, the placement of the ET tube, if that’s the only limiting factor for patient’s ability to speak, we assign a T for endotracheal tube at the end of the GCS score.

02:44 Let’s transition to a discussion of traumatic brain injury but first let’s discuss the anatomy.

02:52 On this image, you see the first layer as the skull and right underneath it is the superior sagittal sinus containing venous drainage blood.

02:59 The yellow outline suggests a subarachnoid space between 2 arachnoid and pia maters.

03:07 I’d like to start the discussion of specific traumatic brain injuries with a discussion of subdural hematomas.

03:13 Classically, subdural hematomas or any intracranial bleeding is associated with high impact to the skull.

03:20 They are traditionally associated with tearing of bridging veins between the brain surface to the dura sinus.

03:27 As you can see in this image, bleeding in the subdural space results in a semilunar or often called moon-shaped crescent hematoma.

03:37 The reason is because the blood separates the arachnoid away from the dura.

03:41 It is not, however, bound by the sagittal sinuses.

03:46 There may or may not be medial deviation or elevation of the intracranial pressure.

03:53 Remember, any space-occupying lesion in the brain may lead to elevations of intracranial pressure.

04:00 We will come back to this concept.

04:02 How do we manage subdurals? Based on the clinical status and the severity of the subdural, management is guided by midline shift, intracranial hypertension, clinical picture such as a comatose or worsening GCS patient or particularly large subdural hematomas as defined by bleeding hematomas greater than one centimeter in thickness.

04:26 If these findings are present, consider calling a neurosurgical colleague for surgical decompression of the hematoma.

04:33 Of course if the patient doesn’t have any of these significant findings, then our job as trauma surgeons is to prevent secondary injury.

04:41 What does it mean to prevent secondary injury? With any trauma, just like when you bang your knee, some swelling is bound to happen.

04:48 We want to decrease swelling and also prevent ischemia or low perfusion of your brain.

04:54 Let’s move on and discuss epidural hematomas.

04:59 Once again, epidural hematomas are associated with high impact to the skull.

05:04 Unlike subdurals which are associated with bridging veins, the epidurals are associated with middle meningeal artery.

05:13 In a clinical scenario, this often describe classic lucid interval where the patient immediately following the trauma may actually be lucid and after about 30 minutes to an hour has a second comatose episode.

05:26 I caution the viewer though that the classic lucid interval is much more discussed and seen in real life.

05:33 And seen on this CAT scan, you notice that the lenticular shape or biconvex shape which is limited by the suture line.

05:41 How do we manage an epidural hematoma? Most epidural hematomas, unlike subdural hematomas, require a surgical decompression.

05:53 If a clinical scenario is presented to you where a patient sustains high velocity or a high-impact brain trauma and they demonstrate a lucid interval, I encourage you to hold epidural hematomas high on your differential list and a list of surgical decompression.

06:11 Once again, like any traumatic brain injury, we want to try to prevent secondary injury.

06:17 Now, let's have a short view on tumor types bleeding in the brain.

06:22 First, there's a traumatic subarachnoid hemorrhage.

06:25 This is type, there is blood in the subarachoid space, so between the pia and the arachnoid mater.

06:31 A head trauma is the most common cause.

06:32 Possible symptoms are headache, nuchal rigidity, photophobia, focal neurologic deficits, and loss of consciousness.

06:39 For a diagnosis, you can use a head CT without contrast.

06:43 To treat such a hemorrhage, you can do a surgical clipping or an intravascular coiling.

06:48 On this slide, you can see two types of intracranial hemorrhage.

06:51 The CT scan on the left depects a case of intracerebral hemorrhage, whereas the slide on the right, shows a case of intraventricular hemorrhage.

06:59 Treatment is mainly supportive.

07:00 In severe cases, an external ventricular drain maybe required to evacuate the blood or even craniotomy.

07:06 Let’s discuss skull fractures.

07:11 Once again, skull fractures are associated with high-impact mechanisms such as an assault with a weapon.

07:18 It’s a classic scenario to have a patient undergo assault with a bat or a metal instrument direct blow to the head.

07:29 Remember that skull fractures are often associated with cervical spine injuries.

07:34 This likely has to be dissociation due to the high impact injury.

07:39 Some very important classic signs include the raccoon’s eyes which is a bruising around the eyes.

07:46 Remember, raccoon eyes and battle’s signs are signs of a basilar skull fracture.

07:52 Battle’s sign is bruising around the mastoid process.

07:55 Just to review, raccoon’s eyes is bleeding or bruising around the eyes and battle’s sign is bruising of the mastoid process just behind the ear.

08:04 And depending on the severity, the patient can have a CSF, cerebrospinal fluid leak.

08:11 Most skull fractures are largely managed non-operatively unless couple of caveat exists.

08:17 One, significant depression of the skull.

08:20 This may require elevation of the skull.

08:22 And most importantly, an open skull fracture uniformly requires exploration and elevation.

08:29 Earlier, I mentioned that one of the clinical signs to evaluate the patient for is intracranial pressure monitoring and to try to prevent intracranial hypertension for high ICPs.

08:42 A very useful and practical equation to remember is the cerebral perfusion pressure.

08:48 The cerebral perfusion pressure is a difference between the mean arterial pressure.

08:53 That’s the systemic circulation minus the intracranial pressure.

08:57 Again, the cerebral perfusion pressure is a difference between your MAPs and your ICPs.

09:04 In severe TBI patients where their GCS is less than 9 were considered comatose.

09:10 Intracranial pressure monitoring may help with diagnosis of further deterioration.

09:16 Remember, comatose patients will not likely participate in your neurological examination.

09:21 Patients in whom we cannot follow the examination, for example, a comatose patient or one who is on severe sedation or anesthesia may also require intracranial monitoring.