17) Head Trauma and Acute Intracranial Events

Question 1

How can primary head injuries be classified?

Answer 1

Focal or diffuse

Question 2

What are examples of focal head injuries?

Answer 2

Haematomas

Contusion

Question 3

What are examples of diffuse head injuries?

Answer 3

Concussion

Diffuse axonal injury

Question 4

What are the main causes of head injuries?

Answer 4

Assault, falls, surgeries, accidents

Question 5

What is cerebral contusion?

Answer 5

‘Bruising’ of the brain whereby blood mixes with cortical tissue due to micro-haemorrhages and small BV leaks

Question 6

What are the types of injury in cerebral contusion?

Answer 6

Coup - brain injured directly under site of impact

Contre-coup - brain injured on the side opposite the impact

Question 7

What are the complications of cerebral contusion?

Answer 7

Oedema, raised ICP, coma

Question 8

What is concussion?

Answer 8

Head injury with a temporary loss of brain function

Question 9

What is the pathophysiology behind concussion?

Answer 9

Trauma -> stretching and injury to axons -> impaired neurotransmission, ion regulation, reduction in cerebral blood flow -> temporary brain dysfunction

Question 10

What is post concussion syndrome and what are some features?

Answer 10

Set of symptoms that may continue for weeks or months after a concussion
Headaches, dizziness, sleeping abnormalities, cognitive signs

Question 11

What is diffuse axonal injury?

Answer 11

Shearing of interface between grey and white matter following traumatic acceleration/deceleration or rotational injuries to the brain

Question 12

What bones could be fractured in a basilar skull fracture?

Answer 12

Temporal, occipital, sphenoid, ethmoid or frontal

Question 13

What are the signs of a basilar skull fracture?

Answer 13

Raccoon eyes
CSF rhinorrhoea and otorrhoea
Battle sign
Haemotypanum

Question 14

How should a basilar skull fracture be managed?

Answer 14

ICP control
Treat complication
Elevation of depressed skull fractures
Surgery if persistent CSF leakage

Question 15

What are the criteria for an urgent head CT?

Answer 15

GCS<13, or <14 for >2hrs
Focal neurological deficit, seizure, LOC
Open/depressed skull fracture

Question 16

What is an extradural haemorrhage?

Answer 16

Collection of blood between inner surface of skull and perioestal dura mater

Question 17

What is the likely cause of an extradural haemorrhage and what population are they common in?

Answer 17

Trauma and/or skull fracture - bleeding from middle meningeal artery
Typically in younger patients

Question 18

How will a patient with an extradural haemorrhage present?

Answer 18

LOC due to impact
Transient recover with ongoing headache (lucid interval)
RICP = CN palsies and brain herniation

Question 19

What is the management for an extradural haemorrhage?

Answer 19

Craniotomy and clot evacuation

Question 20

What are the complications of an extradural haemorrhage?

Answer 20

Permanent brain damage, coma, seizures, weakness, more likely to bleed

Question 21

How does an extradural haemorrhage present on a CT scan?

Answer 21

Lentiform/biconvex haemtoma

Shift of midline

Question 22

What is a subdural haemorrhage?

Answer 22

Collection of blood between meningeal dura mater and arachnoid mater

Question 23

Why is there bleeding in a subdural haemorrhage?

Answer 23

Due to shearing forces on cortical bridging veins

Question 24

What is the likely cause of a subdural haemorrhage and what population are they common in?

Answer 24

Acute SDH - head trauma (acceleration/deceleration)

Subacute/chronic SDH - minor head trauma, more common in elderly

Question 25

How will a patient with an subdural haemorrhage present?

Answer 25

Gradually increasing headache, confusion and cognitive decline

Question 26

How does an subdural haemorrhage present on a CT scan?

Answer 26

Crescent/sickle shaped bleed | Midline shift, loss of cerebral architecture

Question 27

How do acute bleeds differ from longer term bleeds on a CT, and why?

Answer 27

Acute bleeds appear hyperdense | Darken over time (hypodense) due to clot breakdown and liquefying

Question 28

What is the management for a subdural haemorrhage?

Answer 28

Small, chronic evaluated with serial imaging Acute - neurosurgical intervention to relieve RICP Subacute/chronic - burr holes

Question 29

What is a subarachnoid haemorrhage, and its most common cause?

Answer 29

Collection of blood between arachnoid and pia mater | Rupture berry aneurysm

Question 30

What population are subarachnoid haemorrhages common in?

Answer 30

Middle aged patients, <60

Question 31

How would a patient with a subarachnoid haemorrhage present?

Answer 31

Sudden onset, thunderclap headache Meningism Vomiting Fever

Question 32

How does a subarachnoid haemorrhage present on a CT scan?

Answer 32

Collection of blood in basal cisterns | Blood and CSF mixing giving slightly white colour

Question 33

What is the management for a subarachnoid haemorrhage?

Answer 33

``` Lumbar puncture - if no RICP Stabilise Treat cerebral vasospasm Lower systolic BP May need surgical removal of blood ```

Question 34

What are the complications of a subarachnoid haemorrhage?

Answer 34

Hydrocephalus, coma, seizures, cognitive decline, headaches, hypopituitarism

Question 35

What can be done to prevent rupture in high risk berry aneurysms?

Answer 35

Surgical clipping and endovascular coiling

Question 36

What are some risk factors for berry aneurysms?

Answer 36

FH, HTN, heavy alcohol consumption, ADPKD

Question 37

Where are the common sites of berry aneurysms?

Answer 37

ACA, MCA, anterior choroidal artery