Head injury

Question 1

What are the clinical aspects of head injury?

Answer 1

Non missile vs missile
Focal vs diffuse
Primary vs secondary

Question 2

What are the types of head injury?

Answer 2

Scalp injuries
Skull fractures
Intracranial haemorrhage- EDH, SDH, SAH
Intrinsic brain injury- oedema, contusions, lacerations, herniation
Diffuse traumatic axonal injury

Question 3

What are the types of scalp injuries?

Answer 3

Abrasions
Bruises
Lacerations
Incisions
Burns

Question 4

What are the types of skull fractures?

Answer 4

Linear
Depressed
Comminuted
Ring
Contre-coup
Diastatic

Question 5

What is linear skull fracture?

Answer 5

Commonly temporo-parietal from blow or fall onto side or top of head

Question 6

What is depressed skull fracture?

Answer 6

Focal impact which may push fragments inwards to damage the meninges, blood vessels and brain
Force over small area

Question 7

What is comminuted skull fracture?

Answer 7

Fragmented skull
AKA mosaic fracture
Force over large area

Question 8

What is ring skull fracture?

Answer 8

Fracture line encircling foramen magnum
Skull base and cervical spine forced together

Question 9

What is contre-coup fracture?

Answer 9

A fracture of the cranial vault occurring at a site approximately opposite the point of impact

Question 10

What is diastatic fracture?

Answer 10

Follows suture lines
Children

Question 11

What is EDH?

Answer 11

Extradural haemorrhage
Accumulation of high-pressure arterial blood strips dura off inner surface of skull
Egg shaped haematoma that accumulates over a few hours

Question 12

What causes the majority of EDHs?

Answer 12

Fracture of squamous temporal bone
Causes tear in middle meningeal artery

Question 13

What is SDH?

Answer 13

Subdural haemorrhage
Accumulation of low- pressure venous blood from bridging veins
Crescent shaped haematoma

Question 14

When does acute SDH become chronic?

Answer 14

> 2 weeks
Soft jelly consistency of haematoma is broken down into serous fluid
Membrane of granulation tissue forms

Question 15

What causes SDHs?

Answer 15

Any motion which causes rotational/shearing forces can cause the veins to stretch and tear

Question 16

What is SAH?

Answer 16

Subarachnoid haemorrhage
Rapid collapse and quick death
Associated with cerebral contusions
Sudden onset of worst ever headache

Question 17

What is the most common cause of SAH?

Answer 17

Rupture of cerebral artery -> berry aneurysm

Question 18

What is xanthochromia?

Answer 18

The yellowish appearance of cerebrospinal fluid that occurs several hours after bleeding into the subarachnoid space

Question 19

What is the management of SAH?

Answer 19

Coiling
Surgical clipping
Nimodipine to reduce vasospasm (calcium channel blocker)
Insertion of extra ventricular drains of hydrocephalus occurs

Question 20

Why is surgical clipping not first line intervention?

Answer 20

Involves craniotomy is is a more invasive procedure than coiling

Question 21

What are the 2 types of brain contusions?

Answer 21

Coup contusions
Contre-coup contusions

Question 22

What are the types of brain herniation?

Answer 22

Subfalcine herniations
Central herniation
Transtentorial uncal herniation
Cerebellar tonsillar herniation

Question 23

What is transtentorial uncal herniation?

Answer 23

Also known as coning
Transforaminal herniation of brainstem and cerebellar tonsils through foramen magnum

Question 24

What is diffuse traumatic axonal injury?

Answer 24

Tearing of axons in white matter
Due to high force rotation acceleration-deceleration injury

Question 25

What areas of the brain are susceptible to diffuse traumatic axonal injury?

Answer 25

- Corpus callosum - Para-sagittal white matter - Posterior internal capsule - Dorsolateral aspects of rostral brainstem - Cerebellar peduncles

Question 26

What biochemical changes in the brain can cause injury?

Answer 26

Head injury triggers cascade of biochemical changes: - Glutamate causes massive calcium influx which has a neurotoxic effect - Nitrous oxide has a neurotoxic effect

Question 27

What pathology is associated with head injury alongside long bone fractures?

Answer 27

Fat embolism Lodges in lungs and cranial blood vessels Multiple petechial haemorrhages in white matter

Question 28

What is the management of head injury?

Answer 28

Stabilise cervical spine ABC Intubation and ventilation if GCS<8 (Glasgow coma scale) Treat raised ICP Cranial imaging Neuro observation

Question 29

What is involved in treatment of raised ICP?

Answer 29

- Surgery to relieve pressure - Osmotic diuretics e.g. mannitol - Reduce pain - Maintain good PO2, reduce PCO2 - Reduce metabolism- reduce temperature, barbiturates - Sit up patient - Avoid neck compression