Brain Injury

Question 0

What are the five types of brain injury?

Answer 0

1. Acquired brain injury
2. Anoxic injury (lack of oxygen to brain, carbon monoxide poisoning, or other types poisoning)
3. Toxic or metabolic injury (exposure to unsafe chemicals, such as lead, or a buildup of the body’s own chemicals, such as in kidney failure)
4. Encephalitis (usually a virus which causes infection of the brain)
5. Tumors (tumors occupy space and compress brain tissue)

Question 1

What are the types of acquired brain injury?

Answer 1

1. Concussion
2. Contusion
3. Hematoma
4. Diffuse axonal injury (DAI)

Question 3

What is a concussion?

Answer 3

Concussion - a reversible traumatic disruption of nervous function (loss of consciousness) that occurs immediately after an injury

The effects of a concussion can last a varied amount of time (second, minutes, hours, or longer)

Question 4

What is a contusion?

Answer 4

Contusion - bruising of the brain that causes a loss of consciousness

Question 5

What are the two types of contusions?

Answer 5

1. Coup lesion - bruising of brain beneath point of impact

2. Contrecoup lesion - lacerations and contusions on side opposite of impact (generally more severe than coup lesion)

Question 6

What is a hematoma?

Answer 6

Hematoma - collection of blood outside of blood vessels

Question 7

What are the three types of hematomas?

Answer 7

1. Epidural hematoma
2. Subdural hematoma
3. Intracranial hematoma

Question 8

What is a diffuse axonal injury (DAI)?

Answer 8

DAI - Shearing and stretching of white matter (axons) due to rotational acceleration of the head.

Question 9

At what level of the brainstem is diffuse axonal injury most severe?

Answer 9

DAI most severe at where the cerebral hemispheres rotate on the more fixed portion of the brainstem (midbrain-subthalamic level).

The reticular activating system of the brainstem (state of consciousness) is typically affected.

Question 10

What are the ways that tissue death can occur?

Answer 10

1. Acquired brain injury - the resulting force and mechanical disruption causes cell death in focal injury area
2. Hematoma - due to disruption of blood vessels
   2A. Ischemic cell death (due to disruption of blood flow)
3. Intercranial pressure
   3A. Physical compression of tissue
   3B. Ischemic death (due to compression of blood vessels)

Question 11

What is the penumbra?

Answer 11

Penumbra - the area around the focal injury consisting of the cells that did not die due to initial brain injury trauma, but which died due to ischemia, increased pressure, or apoptosis (programed cell death)