1. Yi Sia Surgical HMO The Royal Melbourne Hospital
Head Trauma
Yi Sia
Surgical HMO
The Royal Melbourne Hospital

2. Overview of Anatomy

3. Meninges
Blood Supply to Dura

4. Brain
Circle of Willis

5. Venous Drainage
Ventricular System

6. Physiology Intracranial pressure Pressure within the cranial cavity
Cranial cavity is encased by a skull which is a rigid cavity
80% brain, 10% CSF, 10% blood
Normal ICP < 15mmHg or < 20cmH2O

7. Monro-Kellie Doctrine

8. Cerebral Blood Flow = 50-55ml/100g of brain tissue per minute
Severely elevated ICP can cause decreased CBF and brain ischaemia
CBF depends on cerebral perfusion pressure (CPP)
CPP = MAP – ICP
Autoregulation can compensate for modest reductions in CPP, leading to relatively stable CBF

9. Classifications of Head Trauma
Mechanism
Blunt
High velocity (MVA) vs low velocity (fall, assault)
Penetrating
Gunshot wounds, other penetrating injuries
Morphology
Intracranial lesions
Primary brain injuries
Immediate result of trauma
Secondary brain injuries
Develop later as a result of complications
Skull fractures
Vault
Linear vs stellate, depressed/non-depressed, open/closed
Basilar
With/without CSF leak
Severity
Minor
GCS 13-15
Moderate
GCS 9-12
Severe
GCS 3-8

10. Traumatic Brain Injury
An acquired brain injury caused by a blow to the head or by the head being forced to move rapidly forward or backward, usually with some loss of consciousness
~150 people admitted to hospital with TBI per 100,000 population per year
The leading causes are
Falls (42%)
MVA (29%)
Assault (14%)
Other unintentional injuries
Males > females
Peak incidence is in the age group years

11. Primary Brain Injuries
Concussion
Diffuse axonal injury (intracerebral shearing)
Focal brain injury
Cerebral contusion
Haemorrhage/haematoma

12. Secondary Brain Injury
Cerebral ischaemia/hypoxia
Cerebral swelling/oedema
Hydrocephalus (obstructive, communicating)
Infection
Intracranial bleeding
Extradural haemorrhage
Subdural haematoma
Subarachnoid haemorrhage
Intracerebral haemorrhage

13. Extradural Haemorrhage
Between skull and dura
Injury to middle meningeal artery or one of its branches
Characteristic biconvex shape
May present as decreased consciousness or following a lucid internal

14. Subdural haematoma Between dura and arachnoid
Ruptured communicating veins
Common in elderly
Can be acute, subacute, or chronic

15. SAH and Contusions
SAH
Increased attenuation in CSF spaces – filling of the sulci over cerebral hemispheres
Intracerebral bleed/haemorrhagic contusion
Inferior frontal and anterior temporal lobes are common sites

16. Skull Fractures Indicates severe impact Simple #s – linear or stellate
Depressed #s
Compound #s
Base of skull #s
Anterior cranial fossa – periorbital haematomas (“panda eyes”), subconjunctival haemorrhage, CSF rhinorrhoea
Middle cranial fossa, involving petrous temporal bone – CSF otorrhoea, bruising over mastoid area (“Battle’s sign”)

17. Clinical Assessment Primary survey and resuscitation
A – Airway, C-spine protection
B – Maintain adequate oxygenation (hypoxia causes vasodilatation and raised ICP)
C – Ensure adequate BP (ischaemia results in secondary brain injury)
D – GCS, pupils
Eye Opening
Verbal Response
Motor Response
Spontaneous 4
Oriented 5
Obeys commands 6
To speech 3
Confused
Localises pain
To pain 2
Inappropriate words
Withdraws
None 1
Incomprehensible sounds
Decorticate
Decerebrate

18. Secondary Survey Take an AMPLE history
Fully assess head and neck for injury including
Examination of skull vault
Signs of BOS #s (panda eyes, Battle’s sign, CSF rhinorrhoea/otorrhoea)
Repeat vital signs
Repeat GCS
Neurological examination
General examination for other injuries

19. Signs and Symptoms Common signs and symptoms of raised ICP Headache
Altered mental state, especially irritability and depressed level of alertness and attention
Nausea and vomiting
Papilloedema
Visual loss
Diplopia
Cushing’s triad: HTN, bradycardia, irregular respirations

20. Imaging in Head Trauma
Indications for CT scanning (Canadian CT Head Rule)
CTB is required for patients with minor head injuries (i.e. witnessed LOC, definite amnesia, or witnessed disorientation in a pt with GCS and any one of the following:
High risk for neurosurgical intervention
Moderate risk for brain injury on CT
GCS <15 at 2/24 post injury
Suspected open or depressed skull #
Any sign of BOS #
Vomiting (>2 episodes)
Age >65yo
Amnesia before impact (>30 min)
Dangerous mechanism (e.g. ped vs car, occupant ejected from vehicle, fall from height >3 feet or 5 stairs

21. Medical Management Intravenous fluids Hyperventilation Mannitol
Aim is to maintain normovolaemia
Hyperventilation
Normocarbia is preferred
Mannitol
Acute neurological deterioration in a normotensive pt is a strong indication for administering mannitol
Anticonvulsants
Prophylactic phenytoin reduces the incidence of seizures in the first week of injury

22. Surgical Management Scalp wounds Depressed scalp #s
Intracranial mass lesions (EDH, SDH, intracerebral haematoma)
Decompressive craniotomy/craniectomy
ICP monitor

23. Summary Head trauma causes significant morbidity and mortality
The primary focus of treatment is to prevent secondary brain injury