Cerebrovascular Disease Flashcards
What are the two major causes of neurovascular disease, and what percent does each make up?
Ischemia (85%)
Hemorrhage (15%)
What are the two major types of ischemia?
Global and focal
What can cause global cerebral ischemia? (4)
- Low perfusion (atherosclerosis)
- Acute decrease in blood flow (shock)
- Chronic hypoxia (anemia)
- Repeated episodes of hypoglycemia
What characterizes mild global ischemia? What is an example of this?
Transient ischemia with no lasting damage– insulinoma causing transient hypoglycemia
What characterizes severe global ischemia?
Ischemia that leads to necrosis
Where are the infarcts characteristically located with moderate global ischemia? Why?
- Watershed areas
- are ends of the circulation
What, generally, are the watershed areas of the brain?
Areas of the brain that are fed by the end of a circulation
How many layers of the cortex are there? Which cells here are most vulnerable to damage?
6
-Pyramidal cells
Cortical laminar necrosis = damage to what layers of the cortex?
3, 5, 6
What are the three parts of the brain that are particularly susceptible to ischemia?
- 3,5,6 of cortex
- Pyramidal cells of the hippocampus
- Purkinje layer of the cerebellum
What is the definition of a TIA?
Regional Ischemia that lasts less than 24 hours
What is the defintion of an Ischemic stroke?
Regional Ischemia that lasts longer than 24 hours
What are the three majors ways of developing an ischemic stroke?
- Thrombotic
- Embolic
- Lacunar
Are thrombotic strokes red or pale infarctions? Why?
- Pale
- Thrombus occludes and stays there
Are embolic strokes red or ale infarctions? Why?
- Red
- Embolus is degraded after tissue dies, causing reperfusion, and thus a red infarct
What, generally, is the cause of a thrombotic stroke? Where in the circulation do these generally occur?
- Rupture of an atherosclerotic plaque
- Usually occur at branch points
What is the most common site of origin for embolic strokes? Which artery in the brain is usually involved?
- Left side of the heart
- Middle cerebral artery
What are lacunar strokes?
Strokes that are 2/2 hyaline arteriolosclerosis from HTN or DM
What are the arteries that are most commonly involved in a lacunar stroke?
Lenticulostriate vessels
What do the lenticulostriate vessels arise from? Supply?
- Middle cerebral
- Internal capsule and RF
What are the classical histological pattern seen with lacunar strokes?
“little lakes” in the deep structures of the brain
What are the histological changes that occur in the 12-48 hour timeframe after a stroke?
Red neurons
What are the histological changes that occur in the 24-72 hour timeframe after a stroke?
Necrosis + PMNs
What are the histological changes that occur in the 3-5 day timeframe after a stroke?
Macrophages
What are the histological changes that occur in the 1-2week timeframe after a stroke?
Reactive gliosis + vascular proliferation
What are the histological changes that occur in the more than 2 week timeframe after a stroke?
Glial scar
Match the timeframe following a stroke consistent with the following histological findings: Red neurons
12-48 hours
Match the timeframe following a stroke consistent with the following histological findings: Necrosis + PMNs
24-72 hours
Match the timeframe following a stroke consistent with the following histological findings: macrophages
3-5 days
Match the timeframe following a stroke consistent with the following histological findings: reactive gliosis + vascular proliferation
1-2 weeks
Match the timeframe following a stroke consistent with the following histological findings: glial scar
More than 2 weeks
What is the most common site in the brain for intracerebral hemorrhage from rupture of Charcot-Bouchard aneurysm?
Basal ganglia
What is the usual cause of intracerebral hemorrhage?
Rupture of Charcot-Bouchard microaneurysms
What are Charcot-Bouchard aneurysms?
Small vessel hemorrhages in the brain, 2/2 chronic HTN
What is the usual presentation of subarachnoid hemorrhages?
Sudden onset HA with nuchal rigidity
What will an LP show with a subarachnoid hemorrhage?
Xanthochromia (yellow d/t bili breakdown products)
Bleed on the bottom of the brain = what type of hemorrhage?
Subarachnoid
What is the most frequent cause of subarachnoid hemorrhages?
Rupture of a berry aneurysm
What are berry aneurysms?
Aneurysms that occur at the bifurcations in the circle of Willis
What is the renal disease associated with Berry aneurysms?
ADPKD
What are the two CT diseases associated with Berry aneurysms?
Marfans
Ehlers-Danlos
Where is the most common site of a Berry aneurysm?
Branch points of the anterior communicating artery
Why are berry aneurysms prone to rupture?
Lack a media layer
