Traumatic Brain Injury — Types and Mechanisms

What is the difference between an open and closed brain injury?

• Open injury

  • Penetration through skull into brain

• Closed injury

  • No penetration through skull

• Closed injuries can still cause severe brain damage

What is a primary brain injury?

• Damage occurring at the time of impact

• Examples:

  • Skull fracture

  • Penetrating injury

  • Contusion

  • Direct tissue injury

What is a secondary brain injury?

• Damage occurring after the initial injury

• Results from physiologic consequences

• Examples:

  • Hematoma

  • Hypoxia

  • Ischemia

  • Increased intracranial pressure

  • Post-traumatic epilepsy

What is the difference between a coup and contrecoup lesion?

• Coup

  • Injury directly under the point of impact

• Contrecoup

  • Injury on the opposite side of the brain

  • Caused by rebound of brain within skull

What is an epidural hematoma?

• Bleeding between:

  • Skull

  • Dura mater

• Often associated with traumatic vessel injury

What is a subdural hematoma?

• Bleeding between:

  • Dura

  • Arachnoid

• Commonly related to venous rupture