Cerebrovascular Diseases Flashcards
What three things can go wrong when you have cerebrovascular disease?
- Thrombosis (clot that forms in vessel at certain place)
- Embolism (implies movement- moves from somewhere else and lodges in a vessel, chunk of blood, fat, cholesterol)
- Hemorrhage
What are the two main disease processes with cerebrovascular disease?
- Lack of blood supply (plugged vessel)
2. Hemorrhage from ruptured vessels (too much blood flow)
What is the third leading cause of death in the US?
Cerebrovascular Disease:
- Global cerebral ischemia
- Focal cerebral ischemia
- Hypertensive cerebrovascular disease
- Intracranial hemorrhage
Global Cerebral Ischemia
(lack of blood flow to WHOLE BRAIN)
-Caused by hypotension
-Outcome depends on severity of hypotension
[from transient confusion -> persistent vegetative state or brain death]
-“Watershed” infarcts
What are the two main types of focal cerebral ischemia?
- Ischemic (pale) infarcts [due to thrombi, plaques]
2. Hemorrhagic (red) infarcts [tissue is dead but there is a lot of blood]
What is thrombosis?
- Due to atherosclerosis (most common)
- Usually leads to ischemic infarction
What is an embolism?
- Composed of blood clot (from heart or carotid) or of weird material (marrow - car accident, fat, tumor)
- May lead to hemorrhagic infarction; sometimes leads to ischemic infarction
What does the area look like in ischemic infarcts?
- First two days: white, wet, swollen
- 2-10 days: gelatinous, outlines of infarct visible
- 10-21 days: liquefaction and cavitation (gliosis can’t fill in everything)
Hemorrhagic Infarct appearance:
- Punctate hemorrhages or big hematoma
- Eventual resolution and cavitation
What microscopic changes occur after focal infarcts?
Early changes 1. Red neurons, edema, swollen astrocytes 2. LOTS OF NEUTROPHILS (mostly within first day or two) 3. Less neutrophils, more macrophages Later changes 4. Gliosis begins 5. Even more macrophages 6. Dense gliosis and new capillaries
What patients have Lacunar Infarcts?
Hypertensive patients
What is a lacunar infarct?
It happens when a tiny blood vessel traveling to deep brain becomes occluded.
What are slit hemorrhages?
- Hypertension causes rupture of little penetrating vessels
- Causes little hemorrhages
- Over time, hemorrhages resorb leaving a brownish, slit-like cavity
- See hemosiderin and lipid laden macrophages
What happens with acute hypertensive encephalopathy?
Arises in malignant hypertension
- Diffuse dysfunction: confusion, convulsions, coma
- Increased intracranial pressure
- Swollen brain with petechiae and fibrinoid necrosis of arterioles (tissue in vessel wall is dying)
What is intracranial hemorrhage?
- Can occur anywhere in/around brain
- Hemorrhage around brain (subdural/epidural) usually traumatic
- Hemorrhage in parenchyma or subarachnoid space usually as a result of underlying cerebrovascular disease
What is parenchymal hemorrhage?
- Peak age 60 - high mortality
- Most common cause: rupture of small intraparenchymal vessel
- Can be “ganglionic” or “lobar”
- Most common cause: rupture of small intraparenchymal vessel
What causes a berry aneurysm?
- Etiology unknown
- Smoking, hypertension present in half of patients
- Grow slowly; when > 1 cm, 50% risk of bleeding per year
- Her uncle had this with marfan syndrome - vessels can become weaker
- High mortality when ruptured
- More common art arterial branch points
- Thin walled sac with fragmented media/elastica
What are clinical findings in Subarachnoid hemorrhage?
“Worst headache of my life”
- Loss of consciousness in minutes
- Death in 25-50%
- If survive, regain consciousness
- At risk for vasospastic injury, communicating hydrocephalus -> due to fibrosis in the meninges from repair after hemorrhage
