Cellular Mechanisms of Traumatic Brain Injury

Question 1

Primary injery

Answer 1

Direct contusion, shearing and stretching, vascular response

Cessation of blood flow and metabolism

Rupture of cellular and vascular membranes

Release of intracellular contents

Location and magnitude of damage reflect the characteristics injury

Preventative measures

Question 2

Diffuse Axonal Injury

Answer 2

Twisted and torn, broken axons…

Disease is more difficult to diagnose

Lots of damage

Question 3

SECONDARY INJURY

Answer 3

Delayed process: hours to days

Progressive deterioration

Interplay between ischemic, inflammatory, and cytotoxic processes promoting necrosis and apoptosis

Significantly contributes to post-traumatic neurological disability

Question 4

CELLULAR LEVEL

Answer 4

Apoptosis and necrotic cell death

Excitatory amino acid neurotransmitters
Glutamate and aspartate
Glutamate receptor activation

Influx of Ca 2+ (intracellular and extracellular)

Activation of intracellular proteases
Calpains, phospholipases, endonucleases

Free radicals
Superoxides, hydrogen peroxide, hydroxyl radicals, nitric oxide, peroxynitrite