Ch. 4 - Head injuries Flashcards Preview

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Flashcards in Ch. 4 - Head injuries Deck (29)
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1

Minimum criteria for concussion (according to text)

Period of amnesia

2

Which CN is easily damaged by torsion or herniation of brain?

CN6 - causes diplopia 2/2 unopposed action of medial rectus muscle

3

GCS score indicating severe brain injury

8 or less

4

Decerebrate posturing

Upper limbs adducted and internally rotated but extended at elbow; suggests upper brainstem injury

5

Indications for CT

- loss of consciousness >10 min
- persistent drowsiness
- persistent nausea
- lateralizing neurologic signs
- skull fracture
- CSF rhinorrhea
- injuries necessitating ventilation
- ALWAYS get plain film or CT of cervical spine

6

How long should you observe person with a head injury?

At least 4 hours

7

Why control temperature after head injury?

Elevated temps can increase ICP

8

If concerned about increased ICP, what is PaCO2 goal?

PaCO2 of 30-35

9

Signs of anterior fossa fracture

Subconjunctival hemorrhage extending to posterior limits of sclera (raccoon eyes are just subgaleal), anosmia, nasal tip parasthesia

10

Describe a ‘contre-coup’ injury

Sudden acceleration/deceleration force resulting in opposite ‘poles’ of brain being jammed against cranial vault

11

A concussion is regarded as being severe when the amnesia following the head injury lasts how long?

More than 1 day

12

Causes of traumatic mydriasis

Uncal herniation OR direct trauma

13

Describe difference between simple, depressed, and compound skull fractures

Simple – linear fracture of vault
Depressed – bone fragments depressed beneath vault
Compound – direct communication with external environment

14

What is the first sign of a depressed conscious state?

DROWSINESS

15

What does the term ‘coma’ refer to?

Patient who shows no response to external stimuli, does not obey commands, is unable to utter comprehensible words, and does not open eyes

16

With frontal lobe lesion, gaze will deviate to which side?

Ipsilateral to side of lesion

17

With pontine lesion, gaze will deviate to which side?

Contralateral to side of lesion

18

GCS parameters

Eye opening, best verbal response, best motor response to painful stimulus

19

Decorticate posturing

Upper limbs adducted and internally rotated and flexed at elbow; suggests cerebral white matter and basal ganglia injury

20

Pyrexia is common after head injury. What does pyrexia lasting >2 days suggest?

Traumatic subarachnoid hemorrhage or severe brainstem injury

21

What electrolyte abnormalities can be expected after head trauma?

Retention of sodium and water leading to mild hyponatremia + excretion of potassium

22

Most common sites of infection after head injury

Respiratory and urinary tracts!

23

What should cerebral perfusion pressure be maintained at?

Above 70 mmHg

24

What is the risk of epilepsy following a depressed skull fracture?

15%; continue prophylactic anticonvulsant medication for 1 year if dura was penetrated

25

Signs of middle fossa fracture involving petrous temporal bone

CSF otorrhea (or rhinorrhea) via Eustachian tube, deafness 2/2 CN8 or ossicular injury, hemotympanum, Battle’s sign (bruising over mastoid bone), CN7 palsy

26

Major concern of dural fistula

Infection; tx possible fistula with prophylactic abx (penicillin to cover Streptococcus - most common organism)

27

Indications for surgery in anterior cranial fossa injuries and possible dural fistula

- CSF leakage >5 days
- intracranial aerocele
- episode of meningitis

28

Describe tangential vs. penetrating vs. through-and-through missile injuries

Tangential - does not enter cranium but causes depressed skull fracture
Penetrating - enters cranium resulting in deposition within brain
Through-and-through - enters and exits cranium

29

Doubles mortality in TBI

Hypotension or hypoxia