Cerebrovascular Disorders Flashcards
What generally causes global ischemia?
Cardiopulmonary arrest or extreme hypotension in severe shock
What cell populations in the brain are especially susceptible to ischemia?
Large neurons in Somner section of Hippocampus, Purkinje cells of cerebellum, and neurons of layers 3 and 5 of the cerebral cortex
What is neuroexcitotoxicity?
Injury done to the brain caused by abnormally released neurotransmitters resulting in neuronal depolarization and depletion of energy reserves
A patient suffered prolonged anoxia during a cardiac arrhythmia and developed selective necrosis of layers in the cerebral cortex. Histological analysis showed marked macrophage infiltration. What is the Dx?
Laminar Necrosis
A patient experienced global hypoperfusion and expired. The post-mortem brain is shown below. What is your Dx? Describe the pathogenesis of the infarct.
Watershed (borderzone) infarction; The perfusion pressure drops, and the distal regions of overlapping arterial supply experience perfusion insufficiency.
What is the difference betwixt a hemorrhagic and bland cerebral infarct?
Those that are caused by emboli are hemorrhagic and those caused by thrombosis are bland.
Describe the pathogenesis of cerebral infarcts
- 6-24 hrs - shrunken eosinophilic “red neurons” w/ nuclear pyknosis are present in the infarct
- 24-72 hrs - tissue infiltration with neutrophils and tissue is soft and swollen
- 72-96 hours - neutrophils replaced with macros that clear debris; infarct is mush
- two weeks - astrocytes join macros and form dense fibrillary glial meshwork around dead tissue
What are the three disctinct clinical syndromes of localized ischemia?
Transient Ischemic attack (TIA), Stroke in evolution, Completed stroked
How long do TIAs normally last?
Less than 24 hrs, most last only several minutes
If an internal carotid artery is occluded, what vessel is depended on to supply circulation to the frontal lobe on the affected side?
The anterior communicating artery
An elderly patient sustains multiple minute infarcts and is experiencing cognitive decline. What is your diagnosis?
Multiple infarct dementia
Describe the pathogenesis of malignant hypertension leading to cerebrovascular events
Malignant hypertension causes fibrinoid necrosis of small arteries and arterioles causing minute petechial hemorrhages resulting in Hypertensive Encephalopathy
What are two frequent causes of microcirculation embolization?
Air and fat emboli
A patient sustains multiple bone fractures and expires. Show below is the post-mortem brain. What is your Dx?
Fat emboli
Below is a post-mortem brain of a patient who was pregnant and suffering from dehydration. What is your Dx? What other states could promote this condition?
Superior ssagittal sinus thrombosis; Sickle cell disease, infection or neoplasm causing hypercoagulable state
A patient with hypertension experienced weakening of the walls of cerebral arteries. What is this lesion? Where do they frequently occur?
Charcot-Bouchard aneurysm; Along the trunk of an arteriole
What is this lesion?
Intracerebral Hemorrhage
What is this lesion?
Intraventricular Hemorrhage
What is this lesion?
Pontine Hemorrhage
A patient experiences a lobar hemorrhage. What is the underlying pathology leading to this condition?
The patient likely has amyloid deposition leading to friable vessels and hemorrhage in the white matter of the brain
A patient with Polycystic kidney disease perishes. His cerebral circulation is shown. What is the Dx? Where do these lesions generally occur? What other conditions are associated with this
Rupture Berry Aneurysm; Where blood vessels bifurcate and have inadequate muscularis (congenital defect); aortic coarctation, Ehlers-Danlos syndrome
