Traumatic Brain Injury

Question 1

Are CT’s contrast or non-contrast in head injury?

Answer 1

Non-contrast

Question 2

Steps in CT interpretation?

Answer 2

1) Name & DOB

2) When was scan done?

3) Previous CTs to compare?

4) Is falx cerebri (line in middle) in a straight line?

5) What do ventricles look like?

Question 3

Black vs white on CT?

Answer 3

Black - low density (air)

White - high density (blood, bone)

Question 4

Acute vs chronic bleediong?

Answer 4

Acute - hyperdense (white)

Chronic - hypodense (dark grey)

Question 5

What are the 2 overall types of intracranial haemorrhages?

Answer 5

1) Extra-axial:
- extradural
- subdural
- subarachnoid

2) Intra-axial:
- intraparenchymal
- intraventricular

Question 6

Location of extradural haemorrhage?

Answer 6

Collection of blood between skull and dura mater

Question 7

Typical cause of extradural haemorrhage?

Answer 7

Low impact trauma, typically to temporal region (pterion).

Rupture of middle meningeal artery.

Question 8

Presentation of extradural

Answer 8

1) General: headache, N&V, progressive drowsiness

2) Lucid interval

3) Fixed dilated pupil (due to CN III palsy)

Question 9

CT findings in extradural haemorrhage?

Answer 9

• Hyperdense = acute
• Mass effect possible (shift of midline)
• Biconvex/lentiform shape
• Limited by suture lines of skull

Question 10

Mx of extradural haemorrhage?

Answer 10

Neurosurgical opinion –> conservative or surgical

Question 11

Location of subdural haemorrhage?

Answer 11

Deep to the dura mater of the meninges and superficial to the arachnoid mater.

Question 12

Acute vs chronic subdural haemorrhage?

Answer 12

Acute: develops within 48h of injury

Chronic: develops over 3 weeks

Question 13

What are some behavioural features seen in subdural haemorrhage?

Answer 13

Memory loss, personality changes, cognitive impairment.

Can mimic dementia.

Fluctuating over weeks/months.

Question 14

Mechanism of injury in acute subdural haemorrage?

Answer 14

High impact trauma

Question 15

CT findings in acute subdural haemorrhage?

Answer 15

• HYPERdense (acute bleed)
• Mass effect possible
• Crescent shaped collection
• NOT limited by suture lines

Question 16

Important to consider in patient history with any head injury?

Answer 16

Are they on any anticoagulants?

Question 17

Cause of chronic subdural haemorrage?

Answer 17

Rupture of small bridging veins (between venous sinus & cortex)

Question 18

Risk factors for chronic subdural haemorrhage?

Answer 18

Eldery, alcohol abuse

Question 19

CT findings in chronic subdural haemorrhage?

Answer 19

• HYPODense
• Midline shift possible
• Crescent shaped collection
• Not limited by suture lines

Question 20

CT findings in acute on chronic subdural haemorrhage?

Answer 20

• Hypodense
• Hyperdense
• Midline shift possible
• Crescent shaped collection
• Not limited by suture lines

i.e. both

Question 21

Mx step in all traumatic brain injuries?

Answer 21

Referral to neurosurgery

Question 22

What is the most important initial treatment in SAH?

Answer 22

Nimodipine

Question 23

Role of nimodipine in SAH?

Answer 23

Prevent vasospasm (can lead to ischaemia)

Question 24

Location of SAH?

Answer 24

Between pia and arachnoid membranes

Question 25

What is the subarachnoid space normally occupied by?

Answer 25

CSF

Question 26

What is most common cause of spontaneous SAH?

Answer 26

Saccular (berry) aneurysm

Question 27

Risk factors for berry aneurysms?

Answer 27

- FHx - Female - African descent - PKD - Connective tissue disorders

Question 28

3 key ECG findings in SAH?

Answer 28

1) Tall peaked T waves 2) ST depression 3) Prolonged QT

Question 29

CT findings in SAH?

Answer 29

- Hyperdense - Distributed in cisterns and sulci - Intraventricular involvement

Question 30

Stepwise investigations in SAH?

Answer 30

1) Non-contrast CT head a) If positive --> diagnose SAH b) If negative <6h after bleed --> think about other diagnoses c) If negative >6h after bleed --> consider LP 2) LP at least 12 hours after symptoms onset: a) If negative --> thhink about other diagnoses b) if positive (elevated bilirubin/xanthochroma) --> diagnose SAH 3) Get CT angiography of head

Question 31

Mx of vasospasm in SAH?

Answer 31

Nimodipine

Question 32

What electrolyte abnormality is common in SAH?

Answer 32

Hyponatraemia

Question 33

Mx of seizures in SAH?

Answer 33

Prophylactic levetiracetam

Question 34

Mx of hydrocephalus in SAH?

Answer 34

Drain/shunt

Question 35

Mx of re-bleeding in SAH?

Answer 35

Regular neuro obs Repeat CT

Question 36

Head injury rules: CT <1 hour?

Answer 36

1) GCS <13 on initial assessment 2) GCS <15 2 hours post-injury 3) Suspected open or depressed fracture 4) Basal skull fracture 5) Post-traumatic seizure 6) Focal neuro deficit 7) >1 episode of vomiting

Question 37

Head injury rules: CT <8 hours?

Answer 37

1) Warfarinised 2) LOC/amnesia + - 65+ years - bleeding/clotting disorder (or anticoagulants) - dangerous mechanism of injury - >30 mins retrograde amnesia