TBI, Edema, Hydrocephalus

Question 1

Focal head injuries include

Answer 1

coup/countercoup, hemorrhage, hematoma

Question 2

Diffuse head injuries include

Answer 2

concussion, diffuse axonal injuries (these are often rotational injuries)

Question 3

7 types of skull fractures

Answer 3

linear
comminuted
depressed
"ping pong"
open vs closed
fractures of the frontal sinus
growing fractures- leptomeningeal cyst

Question 4

What age groups are growth fractures found in

Answer 4

Infants

Question 5

What is the Monroe- Kellie Hypothesis

Answer 5

volume of the skull= brain + blood + CSF+ any mass if one is present

Question 6

Which one of the physiologic factors is the least important, why

Answer 6

brain grows slowly

CSF can move into the spinal canal

Question 7

Over what ICP do small increases in volume lead to huge changes of pressure

Answer 7

25 mmHg

Question 8

Cerebral Perfusion Pressure=

Answer 8

MAP- ICP= CPP

Question 9

what happens when ICP inc

Answer 9

when ICP increases CPP decreases
the body has two reactions–> increase systemic BP and dilate cerebral vessels.
Dilating the vessels further increases the ICP leading to a vicious cycle that culminates in cerebral ischemia leading to infraction

Question 10

What is the size of the volume change that over which a small inc in volume causes a large change in pressure

Answer 10

100 cc

Question 11

How can ICP be lowered

Answer 11

Hyperventilation –> CO2 is blown off and if it drops to 25 mmHg–> constriction of intracerebral vessels
mannitol diuresis, req large dose .25-1 g/kg
Neck postion can allow CSF movement
Sedation
Paralysis
Surgical: craniotomy or lobecomy
barbitutaes- lower metabolic demand

Question 12

Why are barbiturates problematic for treating inc ICP

Answer 12

while they lower metabolic demand they can cause hypotension, they make it hard to conduct a neurological exam, and may cause a coma

Question 13

Acute epidural hematoma- 
vessel
history
shape on CT
tx
speed

Answer 13

Middle meningeal artery
trauma to the side of the head- may lose and regain consciousness
lens shaped on CT
treated with craniotomy
fast bc it is arterial

Question 14

Acute Subdural hematoma
vessel
history
shape on CT
tx
speed

Answer 14

bridging veins
patient is old or alcoholic= dec brain mass
Crescent shaped on CT
craniotomy
slow b/c it is venous

Question 15

Chronic Subdural hematoma
complications
what cannot be used to tx this

Answer 15

may cause dementia

cannot drill a burr hole to tx this

Question 16

Order of mortality for chronic/ acute subudural hematomas and acute epidural hematoma

Answer 16

Acute subdural hematoma>acute epidural hematoma&raquo_space; properly managed chronic subdural hematoma

Question 17

What causes brain herniations

Answer 17

ICP gets too high

Question 18

3 types of herniations

Answer 18

Subfalcine
Uncal
Tonsilar

Question 19

Subfalcine herniation

Answer 19

CIngulate gyrus herniates beneath the falx cerebri

can cause compression of ACA and associated musuclar and sensory deficits

Question 20

Uncal herniation

Answer 20

Herniation of the medial temporal lobe (uncus) through the tentorium cerebelli
causes duret hemorhages in the midbrain, CN III compression –> ipsilateral eye will be- down, out, and dilated
PCA compression- occipital or occcipitoparietal infract
Kernohans notch- contralateral side of midbrain is compressed resulting in ipsilateral hemiparesis

Question 21

Tonsilar herniations

Answer 21

Cerebellar tonsils through the foramen magnum which compresses the medulla and causes respiratory depression

Question 22

Concussion

Answer 22

tramatically induced alteration of mental status but without a loss of consciousness
hallmark is CONFUSION AND AMNESIA
severity of concussion is indicated by the length of post-traumatic amnesia
Other signs- delayed response, slurred speech, vacant stare, disorientation

Question 23

Second impact syndrome

Answer 23

Post concussive syndrome
Potentially fatal condition where a second head injury is experienced within one week of the initial concussion.
the subclinical swelling still present from the original injury makes the brain more susceptible to the second injury b/c the first injury disturbs the normal auto regulatory mechanisms leading to vascular congestion and poor brain compliance.
The second injury casuses –> elevated ICP, dilated pupils, respiratory arrest, and death

Question 24

Management of Concussions

Answer 24

ABC’s
airway management avoids hypoxia
fluid resuscitation to avoid hypotension

Question 25

what imaging modality is used in diagnostic management of head injuries

Answer 25

CT