Traumatic brain injury

Question 1

What are 2 broad groups into which primary traumatic brain injury may be classed?

Answer 1

1. Focal: contusion/haematoma
2. Diffuse: diffuse axonal injury

Question 2

What is the cause of diffuse axonal injury?

Answer 2

occurs as a result of mechanical shearing following deceleration, causing disruption and tearing of axons

Question 3

What are 3 types of haematoma which represent a type of focal brain injury?

Answer 3

1. Extradural
2. Subdural
3. Intracerebral

Question 4

What are 2 types of contusions, which represent a form of focal primary brain injury?

Answer 4

1. Adjacent to the side of impact (coup)
2. Contralateral (contre-coup) to the side of impact

Question 5

What is secondary brain injury?

Answer 5

occurs when cerebral oedema, ischaemia, infection, tonsillar or tentorial herniation exacerbate the original injury

Question 6

What are 5 types of secondary brain injury which may exacerbate the original brain injury?

Answer 6

1. Cerebral oeddema
2. Ischaemia
3. Infection
4. Tonsillar herniation
5. Tentorial herniation

Question 7

Why is the brain susceptible to secondary brain injury following trauma?

Answer 7

the normal cerebral auto-regulatory processes are disrupted following trauma, rendering the brain more susceptible to blood flow changes and hypoxia

Question 8

What is the Cushing’s reflex?

Answer 8

hypertension and bradycardia (+ Cheyne Stokes (irregular) breathing - triad)

Question 9

When does the Cushings reflex typically occur following traumatic brain injury?

Answer 9

often occurs late - is usually a pre-terminal event

Question 10

What type of traumatic brain injury can cause extradural (epidural) haematoma?

Answer 10

acceleration-deceleration trauma, or blow to the side of the head

Question 11

Where do the majority of extradural haematomas occur?

Answer 11

temporal region where skull fractures cause a rupture of the middle meningeal artery

Question 12

What are 2 key clinical features of EDH?

Answer 12

1. Features of raised ICP (bradycardia, hypertension)
2. Lucid interval

Question 13

In which 2 lobes of the brain do subdural haemorrhages most commonly occur?

Answer 13

frontal and parietal lobes

Question 14

What are 3 risk factors for subdural haematomas?

Answer 14

1. Old age
2. Alcoholism
3. Anticoagulation

Question 15

How does the presentation of symptoms of a subdural haematoma differ from extradural haematoma?

Answer 15

1. Slower onset of symptoms with SDH than EDH
2. May be fluctuating confusion/consciousness with SDH but not a lucid interval

Question 16

What is the typical presentation of a subarachnoid haemorrhage?

Answer 16

classically causes a sudden occipital headache

Question 17

What is more commonly the cause of a subarachnoid haemorrhage?

Answer 17

ruptured berry aneurysms

Question 18

What is an intracerebral (or intraparenchymal) haemorrhage?

Answer 18

collection of blood within the substance of the brain

Question 19

What are 6 risk factors for intracerebral haemorrhage?

Answer 19

1. Hypertension
2. Vascular lesion e.g. aneurysm or arteriovenous malformation
3. Cerebral amyloid angiopathy
4. Trauma
5. Brain tumour
6. Infarct (esp. stroke patient undergoing thrombolysis)

Question 20

How will patients with an intracerebral haemorrhage typically present?

Answer 20

similarly to an ischaemic stroke - why crucial to obtain CT head in all stroke patients prior to thrombolysis

or decrease in consciousness

Question 21

What will CT imaging show in intracerebral haemorrhage?

Answer 21

hyperdensity (bright lesion) within the substance of the brain

Question 22

What is often the treatment of intracerebral haemorrhage?

Answer 22

often conservative under the care of stroke physicians

large clots in patients with impaired consciousness may warrant surgical evacuation

Question 23

What is the management of large intracerebral haemorrahge with impaired consciousness?

Answer 23

may warrant surgical evacuation

Question 24

What is the appearance of SAH on CT?

Answer 24

hyperdense (whiter) material seen filling the subarachnoid space - most commonly around circle of Willis (65% of berry aneurysms occur in this region) or in the Sylvian fissure (30%)

sometimes blood in interpeduncular fossa or within occipital horns of lateral ventricles