Lecture 26 Pathology of Head Injury

Question 1

Commonest cause of head injury

Answer 1

• Road traffic accidents
• Alcohol-related incidents
• Assaults

Question 2

Name an example of Primary insult

Answer 2

• Focal and/or diffuse brain trauma

Question 3

Name examples of Secondary Insults

Answer 3

• Hypotension – low arterial BP
• Hypoxia – low blood oxygen
• Infection
• Haematoma

Question 4

How do you initially asses head injury

Answer 4

GCS

Question 5

GCS 13-15

Answer 5

Mild injury

Question 6

GCS 912

Answer 6

Moderate injury

Question 7

GCS 3-8

Answer 7

Severe injury

Question 8

Significant complication of head injury

Answer 8

1. Permanent physical disability
2. Post traumatic epilepsy
3. Intracranial infection
4. Psychiatric illness
5. Chronic subdural haemorrhage
6. ‘Punch-drunk’ dementia
7. Fatal outcome (uncommon)

Question 9

Forensic wise how can head injuries arise

Answer 9

Accidental
Homicidal
Suicidal
Natural diseases leading to collapse

Question 10

Name the layers of the head

Answer 10

Skin
Connective Tissue (dense)
Aponeurosis Fascia
Loose Connective Tissue
Pericranium

Question 11

Outer and inner tables of compact bone are separated y what

Answer 11

Spongy bone (diploe)

Question 12

Where are the brainstem and cerebellum located

Answer 12

Hindbrain in posterior cranial fossa

Question 13

What is the function of the brainstem

Answer 13

Part of the brain which contains vital centres providing neurological control of respiration (breathing) and heart function

Question 14

Where in the head is a common site for laceration and why

Answer 14

Scalp, because it is closely applied to the skull

Question 15

Are adult or child skulls more able to deal with force of trauma

Answer 15

Child

Question 16

What are the 2 elements of the skull

Answer 16

i) skull vault (upper part) which includes frontal bone, squamous temporal bones and occipital bone, separated by sutures
ii) skull base (upon which the brain rests) which can be divided into the anterior, middle and posterior cranial fossae

Question 17

What is a common skull fracture

Answer 17

• Linear: commonly temporo-parietal from blow or fall onto side or top of the head and may continue onto the skull base; “hinge” fracture

Question 18

Whats a depressed skull fracture

Answer 18

focal impact which may push fragments inwards to damage the meninges, blood vessels and the brain; risk of meningitis and post-traumatic epilepsy

Question 19

What is a Comminuted fracture

Answer 19

Fragmented skull

Question 20

What is a ring fracture

Answer 20

fracture line encircling the foramen magnum caused by a fall from height, usually landing on the feet, but sometimes the head, leading to the skull base and cervical spine being forced together

Question 21

What is a Contre-coup fracture

Answer 21

fracturing of the orbital plates (anterior fossa) caused by a fall onto the back of the head

Question 22

What types of intracranial haemorrhage are there

Answer 22

Extradural
Subdural
Subarachnoid

Question 23

What is the consequence of Intracranial haemorrhage

Answer 23

Accumulation of blood increases intracranial pressure and results in compression of the brain leadings to reduction in conscious level

Question 24

Why does ICP increase lead to death

Answer 24

Compression of the brainstem due to herniation of the cerebellar tonsils into the Forman magnum

Question 25

Extradural haemorrhage is classical caused by what

Answer 25

Bleeding from middle meningeal artery due to fracture of the squamous temporal bone

Question 26

Define Lucid interval

Answer 26

Victim of injury initially seems to be okay, without neurological symptoms, but can deteriorate catastrophically later, which can be a source of difficulty for clinical staff who may be accused of being negligent if they fail to recognise the possibility of intracranial bleeding

Question 27

What typically causes subdural haemorrhage

Answer 27

Bleeding from bridging veins which pass from the surface of the brain to drain into the large venous channels within the dura. Motion that causes rotational shearing forces can cause veins to be stretched and torn

Question 28

What is the most common cause of Subarachnoid haemorrhage

Answer 28

Bleeding beneath the arachnoid membrane
Natural disaster- rupture of cerebral artery aneurysm
Cerebral contusions (bruising to the brain)

Question 29

Define Traumatic Basal SAH

Answer 29

Result of a forceful impact to the upper part of the side of the neck causing abrupt rotational movement of the head leading to rupture of the vertebra-basilar circulation

Question 30

Causes of intrinsic brain injury

Answer 30

Cerebral oedema
Cerebral contusion and laceration
Coup contusion
Cotre coup

Question 31

Define a contre coup contusion

Answer 31

caused by a moving head striking a fixed object or unyielding surface - contusions are found diametrically opposite the site of head impact, e.g. a fall onto the back of the head would result in contusions on the frontal and temporal poles and on the undersurface of the frontal lobes

Question 32

What is Diffuse Traumatic Axonal injury

Answer 32

serious rotational forces applied to the brain tissue causing shearing of axons such as vehicular collisions and falls from heights

Question 33

What areas are susceptible to tDAI

Answer 33

corpus callosum, para-sagittal white matter, posterior internal capsule and dorsolateral aspects of the rostral brainstem, as well as the cerebellar peduncles

Question 34

How are victims clinically who are experiencing tDAI

Answer 34

Comatose