Physiological Psychology Lecture #7 Flashcards
Traumatic Brain Injury
“When a sudden, external, physical assault damages the brain”.
In the U.S.:
- 27,000 are hospitalized.
- 52,000 die from their injury.
Causes of traumatic brain injury
In adolescence and young adults:
- Motor vehicle collisions.
In older adults:
- Falls
TBI Sex and Age Breakdown
- Most common age: 15-24
- More common in men than women (at age 15-24), becomes more even as age progresses.
Closed Brain Injury
Non-penetrating injury to the brain-no break to the skull. Injury can result from:
- Rapid forward and backward movement of brain in the skull–tearing and bruising of brain tissue and blood vessels.
Coup
point of impact
Countercoup
Injury of opposite side
Diffuse Axonal Injury
Car crash, falls, sports, shaken baby syndrome.
Penetrating Brain Injury
Penetrating or open head injuries where there is a break in the skull. Injury results from:
- Penetrating objects, and skull bone fragments damaging brain tissue and blood vessels = deprivation of normal blood supply and accumulation of blood.
- Cognitive impairment tend to be more focal.
Ischemia
Deprivation of normal blood supply
Hemorrhage
Accumulation of blood.
Diffuse Axonal Injury (DAI)
“The shearing (tearing) of the brain’s long connected nerve fibers (axons) that happens when the brain is injured as it shifts and rotates inside the bony skull”.
- Damage to white matter.
- Changes are microscopic.
- Can lead to disorders of consciousness (persistent vegetative state, coma).
- Difficult to see on CT scan or MRI
- Can occur without other visible damage.
Grade 1 Axonal Injury
Mildest form of DAI
- Microscopic changes in the white matter of the cerebral cortex, corpus callosum, brain stem, and cerebellum.
Grade 2 Axonal Injury
Moderate form of DAI (diffuse axonal injury)
- Grossly evident focal lesions isolated to the corpus callosum.
Grade 3 Axonal Injury
Severe form of DAI
- Additional and severe focal lesions on the brainstem itself.
Primary Injury
- Skull lacerations
- Skull fractures
- Contusions
- Cerebral lacerations
- Intercranial hemorrhage
- Diffise axonal injury