head injury and trauma

Question 1

which type of head injury is associated with lucid intervals?

Answer 1

extradural haematoma

Question 2

what are primary head injuries?

Answer 2

1. focal
   - contusions (bruising)
   - haematoma - can be extradural or subdural
2. diffuse
   - diffuse axonal injury

Question 3

which artery has most likely ruptured during a extradural haemorrhage?

Answer 3

middle meningeal artery

Question 4

what are risk factors for subdural haematoma?

Answer 4

old age, alcoholism and anticoagulation.

Question 5

what types of headaches do subarachnoid haemorrhages classically cause?

Answer 5

sudden occipital headache. Usually occurs spontaneously in the context of a ruptured cerebral aneurysm

Question 6

why may you get pupillary dilation with a head injury?

Answer 6

– occulomotor 3rd nerve compression

- the eye may also look down and out

Question 7

why might you get muscle weakness with a head injury?

Answer 7

– corticospinal tract compression

Question 8

where is the middle meningeal artery found?

Answer 8

the pterion

Question 9

what structures are responsible for subdural haematomomas?

Answer 9

bridging veins- these are vulnerable to rapid acceleration and deceleration

Question 10

why do extradural haematomas cause a rapid rise in intracranial pressure?

Answer 10

build of blood trapped between the dura mater and skull.
dura mater is attached tightly to the sutures of the skull, so the blood can’t cross these sutures and is trapped with nowhere to go.

This means the intracranial pressure can increase rapidly.

Question 11

where does blood collect in subdural haematoma?

Answer 11

blood collects between the dura mater (the outer layer of the meninges) and arachnoid mater, which is the middle layer of the meninges.

Question 12

why is subdural haematoma more common in elderly and alcoholics?

Answer 12

because of brain atrophy the riding veins are stretched out and so are more vulnerable to rupture

Question 13

why are the effects of subdural haematomas slow?

Answer 13

• veins rather than arteries bleed out slowly

- bleeding isn’t restricted by suture so it can spread out and pressure won’t build up

Question 14

what is the equation for working out cerebral perfussion pressure?

Answer 14

CPP= mean arterial pressure- intracranial pressure

Question 15

what is a subacute subdural heamatoma?

Answer 15

2 days- 2 weeks

Question 16

What is an acute subdural heamatoma?

Answer 16

<2 days

Question 17

what is a chronic subdural haematoma?

Answer 17

> 2 weeks

Question 18

what is the most common cause of subarachnoid haemorrhage?

Answer 18

head trauma

Question 19

which genetic factors can predispose an individual to a cerebral anneyurism?

Answer 19

• marfans
• elhers danklos syndrome
• polycystic kidney disease

Question 20

lumbar puncture for spontaneous vs dramatic subarachnoid haemorrhage?

Answer 20

spontaneous:
- can do a lumbar puncture and it will show xanthocromia
traumatic:
- contraindicated due to increase intracranial pressure-> it may cause herniation

Question 21

what are indications for head CT?

Answer 21

amnesia for >30 minutes prior to event
age >65
dangerous mechanism of injury

Question 22

how does hydrocephalus appear on CT?

Answer 22

ventricular dilatation

Question 23

what can diffuse axonal injury lead to?

Answer 23

• post traumatic coma lasting > 6hrs

Question 24

which type of herniation is the most dangerous?

Answer 24

• tonsil herniation as this can push down on the brain stem

- this is a type of infratentorial herniation

Question 25

what wish cushing’s triad?

Answer 25

hypertension
irregular breathing
bradycardia.
represent a physiological response of the central nervous system to increased intracranial pressure

Question 26

what is the most sensitive test for diffuse axonal injury?

Answer 26

MRI

Question 27

what is something that can happen in road traffic accidents in people wearing seatbelts?

Answer 27

carotid artery laceration

Question 28

what happens to pupils when the intracranial pressure is increased?

Answer 28

pupillary dilation because there will b compression of the 3rd- oculomotor nerve