Head Trauma & AIE

Question 1

Describe the typical events leading to an extradural haemorrhage

Answer 1

Arterial - MMA, between skull and periosteal layer of dura mater
Typically presents following contact sport or high energy motor vehicle accidents (high impact trauma)
Following injury they regain a normal level of consciousness but gradually deteriorate over next few hours
Younger patients (dura more adherent to periosteum and less likely to split in older patients)

Question 2

Describe the typical events leading to a subdural haemorrhage

Answer 2

Venous - emissery veins, between the dura and arachnoid mater
Acute/subacute (3-7 days)/chronic (2-3 weeks)
Elderly (weaker veins) although all ages
*crescent shape on CT

Question 3

Describe the typical events leading to a subarachnoid haemorrhage

Answer 3

Arterial - circle of willis berry aneurysms, between the pia and arachnoid mater
Traumatic or spontaneous e.g. aneurysm, arteriovenous malformation
Classically presents with thunderclap headache at back of head, neck stiffness, vomiting, photophobia

Question 4

Describe the typical events leading to an intracerebral haemorrhage

Answer 4

Haemorrhagic stroke, bleeding within brain tissue
Trauma (spontaneous)
Signs and symptoms correspond to area of brain affected by bleed

Question 5

Describe diffuse axonal injury

Answer 5

Acceleration/deceleration causes brain to move within skull –> shearing and injury to axons at the grey-white matter junction
Instantaneous loss of consciousness –> persistent vegetative state

Question 6

How can fluid be tested to confirm it is CSF?

Answer 6

On filter paper - halo/ring sign
Urine dipstick - + glucose
Beta-2 transferrin levels

Question 7

Describe the clinical signs of a basal skull fracture

Answer 7

Periorbital ecchymosis (raccoon’s eyes)
Mastoid ecchymosis (battle’s sign)
CSF rhinorrhoea
CSF otorrhoea

Question 8

Define the term ‘intracranial pressure’ and when it is raised

Answer 8

Pressure within the cranial cavity, usually 5-15mmHg

Raised = sustained >20mmHg for >5 minutes

Question 9

List symptoms typical of a raised ICP headache

Answer 9

Generalised/bilateral, ache, no radiation, nausea and vomiting, transient uniocular loss of vision, altered mental state, worse first thing in morning, when lying down, bending forward, coughing, relieved by sitting/standing up

Question 10

List signs typical of a raised ICP

Answer 10

Papilloedema (impaired axoplasmic flow)
Oculomotor nerve palsy (uncal herniation)
Abducens nerve palsy (thin nerve, long course through cranium)
Loss of vestibule-ocular reflex (brainstem death
Confusion/irritability
Reduced GCS
Decorticate/decerebrate positioning

Question 11

Define the term ‘hydrocephalus’

Answer 11

Excess CSF volume due to excess CSF production or disruption of CSF flow through the ventricles or disruption of absorption at arachnoid granulations