Traumatic Brain Injury Part 3

Question 1

Why do subdural Hematoma’s happen?

Answer 1

The tearing or shearing of the bridging veins (veins that connect the brain to the dura)

Question 2

What is the typical mechanism that causes SDH

Answer 2

Acceleration deceleration injuries or rotational forces. This mechanism involves sudden stops causing the brain to shift rapidly resulting in the bridging veins to get torn

Question 3

Acute SDH vs Chronic SDH

Answer 3

Acute ; occurs soon after head injury, rapid onset of increased ICP
Chronic ; develop over days after minor trauma, seen in elderly patients or those on anti coagulation therapy

Question 4

Why is SDH often more insidious than EDH?

Answer 4

This is due to the venous bleeding in SDH. Because its venous bleeding its slower than the arterial bleeding in EDH (middle meningeal artery)

Question 5

What can shaken baby syndrome lead to? (4)

Answer 5

• hemorrhaging in the brain
• coup-countercoup injuries
• diffuse axonal injuries
• venous bleeding in the bridging veins

Question 6

Why are subderal hematomas referred to as the great imitator?

Answer 6

This is because they can present gradually due to the venous bleed and mimic other conditions. It also goes unnoticed for days and presents as a minor injury

Question 7

What are complications from subderal hematomas?

Answer 7

• blood stasis from the bleed could cause coagulation
• the clot might get dislodged and cause a rebleeding

Question 8

What is a hemorrhagic stroke?

Answer 8

A type of stroke caused by bleeding around the brain

Question 9

What causes hemorrhagic strokes?

Answer 9

• head trauma
• spontaneous rupture of blood vessels (often associated with medical condition and risk factors)

Question 10

What is an ischemic stroke?

Answer 10

This is a blockage to blood flow to the brain from a blood clot

Question 11

What are risk factors for hemorrhagic strokes?

Answer 11

• elderly
• debilitated individuals
• chronic alcoholics
• pts on anticoagulation therapy

Question 12

What is The inflammatory response of blood stasis

Answer 12

Macrophages and RBC come to the site to clean up the area but this increases solute concentration and osmolarity which causes a fluid shift and results in edema

Question 13

What is a sign of arterial brain bleeds?

Answer 13

• thunder clap headaches
• brief loss of consciousness
• vomiting
• neck stiffness

Question 14

What are the risk factors for arterial brain bleeds?

Answer 14

• over >50 yoa
• smoking
• hx of brain aneurysms
• chronic HTN
• use of sympathomimetic drugs

Question 15

What are sentinel bleeds?

Answer 15

A slow initial bleed that may present with transient neuro deficits

Question 16

What are non traumatic causes of interventricular hemorrhage and intra cerebral hemorrhage?

Answer 16

• Arteriovenous malformation (AVM)
• aneurysms
• brain tumours

Question 17

What are traumatic causes of intra cerebral hemorrhage?

Answer 17

• depressed skull fracture
• acceleration/deceleration injuries (less common)

Question 18

When would free radicals be released and what impact do they have?

Answer 18

Thy are released by WBC and leukocytes during inflammatory responses. They increase cellular damage and tissue destruction and cause further inflammation/edema

Question 19

During injury to the brain, there is an elevated metabolic rate and increased MVO2. However there is inefficient oxygen utilization due to ischemia, edema, ect. This causes the metabolic process to shift towards what?

Answer 19

Acidosis

Question 20

Hyperventilation is recommended for ICP management. Why?

Answer 20

It lowers arterial CO2 levels which leads to cerebral vasoconstriction thus reducing hydrostatic pressures within the vessels

Question 21

What is autophagy? what is the relation between autophagy and TBI

Answer 21

A cellular process responsible for maintaining homeostasis by degrading and recycling damaged cellular components. Hypoxia from TBI impairs Autophagy leading to a build up of these byproducts