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
