Reasons for cerebral hypoxia
- Functional hypoxia (anemia, high altitude)
- Ischemia (transient or permanent)
Ischemic encephalopathy
The brain is highly dependent on blood supply.
- Neurons are far more sensitive than glial cells to ischemia
- Do not have glycogen stores
- Some regions of the brain are more sensitive
Morphology
- Swelling and cerebral edema are seen
- Red neurons -- dying neurons
- Liquefactive necrosis that is resolved within several weeks and replaced by gliosis
Types
- Global
- Focal
Global
Due to systemic hypotension (>50mmHg), seen in cardiac arrest and shock.
- If the ischemia is short-lasting, there will be a complete recovery
- If the ischemia is long-lasting, there will be widespread neuronal death
- "Brain death" refers to individuals who lost all of their voluntary and reflex brain function
- "Respirator brain" refers to the autolysis of the brain that requires a ventilator, since even the respiratory center is damaged
- The ventilator comes after the brain damage! It does not induce brain damage
- Watershed infarcts refer to infarcts formed in vulnerable regions, such as the border between