Neurotrauma

Question 1

What are Tier 1 therapies in TBI management

Answer 1

Head of bed 30 degrees
Avoid restrictive compression around neck 
Avoid hypotension
Avoid hypoxia 
CPP 60-70
PaCO2 35-40 
Avoid hyperthermia
Maintain euglycemia 
Sedation 
EVD
Seizure prophylaxis

Question 2

What are Tier II therapies in TBI management

Answer 2

Neuromuscular blockade
Osmotic therapy
Mild hypothermia (to 35 degrees)

Question 3

What are Tier III therapies in TBI management

Answer 3

Mod hypothermia (to 34 degrees)
Consider surgical decompression
Barbituate coma

Question 4

What are the 3 gradings in diffuse axonal injury

Answer 4

Grade I: grey-white matter interfaces
Grade II: additionally involves corpus callosum
Grade III: additionally involves brainstem

Question 5

What is the clinical hallmark of DAI

Answer 5

decreased level of consciousness

Question 6

What is the mechanism of diffuse axonal injury

Answer 6

shearing forces on neurons - disrupt neurotransmission
Often occur at grey-white matter junctions
Usually by rotational forces or deceleration

Question 7

What percentage of ruptured aneurysmal SAH die? Have good outcome?

Answer 7

10% die

1/3 have good outcome

Question 8

What are 5 risk factors for cerebral aneurysms

Answer 8

Connective tissue disease - Ehlers Danlos
Polycystic kidney disease
Moyamoya
Familial aneurysms
Cigarette smoking
Hypertension 
Coarctation of the aorta

Question 9

When does vasospasm occur after aneurysmal SAH?

Answer 9

no earlier than day 3

peaks at days 7-8

Question 10

List 5 associated conditions with Posterior Reversible Leukoencephalopathy Syndrome (PRES)

Answer 10

Hypertensive encephalopathy
Pre-eclampsia
Acute/Chronic renal failure
MAHA
Vasculitis (SLE)
Chemo/immunosupression drugs
Contrast media exposure
Blood transfusion

Question 11

What are 4 clinical manifestations of PRES?

Answer 11

Headache
Visual disturbances (hemianopia, visual neglect, cortical blindess, auras)
Seizures (can be in status)
Altered consciousness

Question 12

What are typical neuroimaging findings in PRES?

Answer 12

symmetric white matter edema in posterior cerebral hemispheres
*parieto-occipital regions
May be seen on CT but best characterized on MRI

Question 13

What 2 clinical features are 100% specific for poor clinical outcome in brain injury

Answer 13

1. Absent or extensor motor response on day 3

2. Absent pupillary or corneal responses on day 3

Question 14

What is the pathway of the corneal reflex?

Answer 14

Afferent CN V1

Efferent CN VII

Question 15

What is the pathway of the pupillary reflex

Answer 15

Afferent CN II

Efferent CN III

Question 16

Features of subfalcine herniation?

Answer 16

Midline shift on CT as cingulate gyrus herniates under the falx cerebri
May compress on circle of willis and cut off supply to ACA (motor leg)

Question 17

Features of transtentorial (uncal) hermiation?

Answer 17

*most common herniation syndrome
Brain compressed across tentorium, slips downwards towards brainstem
Ipsilateral culomotor nerve dysfunction - aniscoria, ptosis, fixed dilated pupil, downward and out (later finding) -
May have contralateral or ipsilateral (false localizing, Kernahan’s notch syndrome) hemiparesis from compression on corticospinal tracts
Progresses to decerebrate posturing and abnormal respiratory patterns

Question 18

Features of tonsillar herniation?

Answer 18

Cerebellar tonsils herniate through foramen magnum
Pinpoint pupils, flaccid quadriplegia from compression of bilateral corticospinal tracts
Compress medulla and cardiorespiratory centres