Pathophysiology Of TBI

Question 1

Which type of brain edema leads to extracellular edema and which leads to intracellular edema?

Answer 1

Vasogenic edema leads to extracellular edema

Cytogenic edema leads to intracellular edema

Question 2

What 2 neurotransmitters are involved in TBI that leads to excitotoxicity

Answer 2

Glutamate and potassium

Question 3

Vasogenic edema is due to…

Answer 3

Protein rich fluid leaving damaged blood vessels in the brain and causing fluid to accumulate extracellularly

Question 4

What do you see on MRI that indicates DAI

Answer 4

White matter petechial hemorrhages

Question 5

How is brain swelling seen on CT?

Answer 5

Collapse of ventricles and loss of CSF cisterns

Question 6

What causes the white matter changes characteristic of DAI?

Answer 6

Injury to axons with increased permeability of axons leading to calcium influx and cytoskeletal abnormalities

Question 7

When does secondary injury occur after TBI?

Answer 7

<24 hours to days

Question 8

Grade 1, 2 and 3 of DAI

Answer 8

Grade 1 = widespread damage with no focal findings.
Grade 2 = widespread damage with focal findings, most commonly the corpus callosum
Grade 3 = damage to brainstem

Question 9

When does primary injury occur after TBI

Answer 9

Minutes to hours after impact

Question 10

Plasticity occurs via 2 mechanisms

Answer 10

Collateral sprouting and functional reorganization/unmasking neural reorganization)
(PUN: Plasticity = Unmasking + Neuronal sprouting

Question 11

Epidural hematoma results from injury to what vessels

Answer 11

Middle meningeal artery or veins

Question 12

2 types of brain edema

Answer 12

Vasogenic and cytogenic

Question 13

What kind of shearing forces cause DAI

Answer 13

Acceleration-deceleration forces and rotational forces

Question 14

_____________ is the process by which neuronal damage occurs as a result of a massive surge in _______________

Answer 14

Excitotoxicity; Neurotransmitters

Question 15

Subarachnoid hemorrhage results from injury to what vessels

Answer 15

Ruptured aneurysms and AVMs

Question 16

Focal ischemia after TBI occurs secondary to…

Answer 16

Vasospasms

Question 17

3 most common locations for DAI in the brain

Answer 17

1. Corpus callosum
2. Central white matter
3. Midbrain

Question 18

Subdural hematoma results from injury to what vessels?

Answer 18

Bridging veins

Question 19

2 most common locations for brain contusions from a TBI

Answer 19

1. Inferior frontal lobe

2. Anterior temporal lobe

Question 20

Damage to one region of brain can produce altered function in other areas of the brain that were not severed

Answer 20

Diaschisis

Question 21

What chemical process directly causes cell death after TBI

Answer 21

Increase in calcium influx

Question 22

Brain swelling vs edema

Answer 22

Swelling = increase in blood volume; occurs within 24h
Edema = increase in brain water; occurs after swelling

Question 23

Is diffuse axonal injury considered primary or secondary injury?

Answer 23

Primary

Question 24

Most common cause of unconsciousness during and following the first 24 hours TBI

Answer 24

Diffuse axonal injury

Question 25

Subdural shape seen on CT

Answer 25

Concave/crescentic mass

Question 26

Capability of damaged brain to repair itself by means of morphological and physiologic responses

Answer 26

Plasticity

Question 27

Shape of Epidural hematoma seen on CT

Answer 27

BiConvex mass