Transcript Brain Damage & Neuroplasticity

Brain Damage & Neuroplasticity
Etiology of Brain Damage
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Traumatic Brain Injury (TBI)
Cerebrovascular Injury (CVI)
Tumors
Anoxia (e.g., near drowning, drug overdose)
Toxins (e.g., lead)
Diseases (e.g., Herpes, encephalitis)
Seizures
Traumatic Brain Injury
1. Open Head Injury (e.g., missile wound) –
focal damage and some diffuse damage
Classic Case: Phineas Gage
Phineas Gage:
Frontal Lobe
Injury
Rosenzweig et al., 2002
Prefrontal
Cortex:
Organizes
cognitions,
emotions and
behavior.
Blue – dorsolateral prefrontal
Green – orbitofrontal region
Rosenzweig et al., 2002
Prefrontal Cortex: Distinguishes Homo
Sapiens from other mammals
Rosenzweig et al., 2002
Behavioral Disruption Following
Prefrontal Lesions
(note: any type of brain damage can result in a Prefrontal Syndrome)
Rosenzweig et al., 2002
Traumatic Brain Injury (cont’d)
2. Closed Head Injury
- concussion (mild brain injury)
- moderate to severe brain injury: classification
dependent on the degree of post-traumatic
amnesia (or anterograde amnesia – deficits in
new learning)
- Pathophysiology of TBI
~ focal damage (coupe & contra-coupe)
~ diffuse damage (shearing & tearing of
axons referred to as diffuse axonal
injury)
Functional Changes:
• Depends on where the focal damage is:
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Frontal?
Parietal?
Occipital?
Temporal?
Limbic System?
Basal Ganglia?
Hypothalamus?
Brainstem?
Identify behaviors
associated with these
areas.
Focal damage can affect
specific behaviors and
impact related behaviors.
Diffuse damage will cause
widespread tissue loss.
Cerebrovascular Injury
• Stroke (Ischemia – loss or reduction of
blood circulation)
Thrombosis (large blockage)
Transient Ischemic Attack (TIA)
What causes the brain damage? (next slide)
Stroke: Source of Injury and Treatment
Rosenzweig et al., 2002
Behavioral
Disruption
following Right
Hemisphere
Stroke:
Hemispatial
Neglect
Rosenzweig et al., 2002
Other Causes of Brain Damage:
• Tumors – these can be small to large cyst-like
tumors or sticky, tentacle-like tumors
• Toxins – heavy metals such as lead cause damage.
Lead replaces the oxygen molecule, causing
widespread damage (sources: lead paint, leaded
gasoline fumes)
• Anoxia – loss of oxygen causes diffuse damage
• Diseases – numerous…
• Seizures – uncontrolled electrical activity cause
Glutamate Toxic Casacade (as occurs with stroke)
Did you know that…
• if you understand the functional
organization of the brain in a healthy
person, you will be able to understand
functional changes following brain damage?
AND (if you understand this)
• you will be able to understand problems
associated with psychiatric disorders?
Remember – There is always recovery
due to Neuroplasticity
Rosenzweig et al., 2002