Head Injury

Question 1

What is a primary insult?

Answer 1

Focal and/or diffuse brain trauma

Question 2

What is a secondary insult?

Answer 2

Hypotension - low arterial BP
Hypoxia - low blood oxygen
Infection
Haematoma - bleeding in/ around brain

Question 3

What is used for initial assessment of head injury?

Answer 3

Conscious level assessed using GCS
Scored out of 15
Correlates with severity of head injury
13-15 is mild, 9-12 moderate, 3-8 is severe

Question 4

What can be the clinical consequences of head injury?

Answer 4

Permanent physical disability, post traumatic epilepsy, intracranial infection, psychiatric illness, chronic subdural haemorrhage, punch drunk dementia and fatal outcome

Question 5

What does the brainstem and cerebellum form?

Answer 5

Hindbrain
Positioned in posterior cranial fossa

Question 6

What does the brainstem contain?

Answer 6

Vital centres providing neurological control of respiration and heart function

Question 7

Describe some scalp injuries

Answer 7

Similar to skin - abrasions, bruises, lacerations and incisions
Common is laceration
Blunt force injury may not be visible on the scalp and hair can obscure the sizable injuries
May only have bleeding/bruising in deeper layers of scalp

Question 8

Is adult or infant skull more able to cope with distortion?

Answer 8

Infant as their skulls are not fully fused yet

Question 9

What is a linear skull fracture?

Answer 9

Commonly temporo-parietal from blow or fall onto side or top of head and my continue to skull base - hinge fracture

Question 10

What is the depressed skull fracture?

Answer 10

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

Question 11

What is a comminuted skull fracture?

Answer 11

Mosaic
Fragmented skull - fracture radiates from point of impact

Question 12

What is a ring skull fracture?

Answer 12

Fracture line encircling the foramen magnum caused by fall from height, usually landing on feet or head
Leading to skull base and cervical spine being forced together

Question 13

What is a contre-coup fracture?

Answer 13

Fracturing of orbital planes in anterior fossa caused by a fall onto back of head
Oppisite side to injury

Question 14

Describe intracranial haemorrhage

Answer 14

Can be extradural, subdural and subarachnoid haemorrhage
Accumulation of blood within rigid skull so increase ICP and compression of brain - LOC

Question 15

What can happen if ICP increases?

Answer 15

Without innervation then ultimately death will occur by compression of brainstem as herniation of cerebellar tonsils into foramen magnum

Question 16

Describe an extradural haemorrhage

Answer 16

Bleeding occurring between dura and skull - strips dura off inner surface of skull
Under high pressure as arterial bleeding

Question 17

What is a common cause of extradural haemorrhage?

Answer 17

Bleeding from middle meningeal artery where it crosses the inner aspect of squamous temporal bone, due to fracture with secondary damage to artery

Question 18

Describe the lucid interval in EDH

Answer 18

Victim of injury seems okay, without neurological symptoms but can deteriorate quickly after

Question 19

Describe a subdural haemorrhage

Answer 19

Bleeding underneath the dura and above the arachnoid
Usually caused by bleeding from bridging veins which pass from surface of brain to drain large channels within dura

Question 20

How does subdural haemorrhage happen?

Answer 20

Rotational or shearing forces cause bridging veins to stretch and tare
Frequently occurs without skull fracture
Small brain at more risk as greater compacity for movement

Question 21

What can chronic subdural haemorrhage lead to?

Answer 21

Chronic confusion - may be mistaken for dementia
Particularly in the elderly

Question 22

Describe subarachnoid haemorrhage

Answer 22

Bleeding beneath arachnoid membrane
Common cause is natural disease - rupture of cerebral artery (berry) aneurysm
Also seen in association with cerebral contusions

Question 23

Describe traumatic basal SAH

Answer 23

Typically result of a forceful impact to upper part of side of neck causing abrupt rotational movement of head leading to rupture of vestibulo-basilar circulation - collapse and rapid death

Question 24

What are intrinsic brain injury?

Answer 24

Cerebral oedema - brain swelling with raised ICP
Cerebral contusion and laceration - direct mechanical damage to brain substance

Question 25

What is coup contusion?

Answer 25

When head is struck with heavy blow - found directly under site of impact

Question 26

Describe diffuse traumatic axonal injury

Answer 26

Not just caused by trauma
Diagnosis can only be made microscopy of brain tissue but may get concomitant damage to small blood vessels within brain

Question 27

What areas are particularly susceptible to displaying tDAI?

Answer 27

Corpus collosum, para sagittal white matter, posterior internal capsule and dorsolateral aspects of rostral brainstem and cerebral peduncles