Lectures 62-63: Cerebrovascular Disease Flashcards
Thromboembolus is often…why? Particularly what territory?
Hemorrhagic –> when the clot recedes, blood flows into damaged tissue; carotid
Thrombosis is different from thromboembolus how? Particularly in what territory?
Local (clot forms over local plaque); posterior circulation
Acute infarct: histological appearance; what it leads to that is dangerous; timeline for peak edema
Pallor, edema, early PMNs; can lead to swelling and herniation; 24 - 48 hours
Subacute infarct: cellular and tissue response; timeline
Macrophage infiltration, vascular proliferation; demarcation, organization, contraction; organization happens over days - months
Chronic/remote infarct forms what and this leads to what (proper name)
Cystic cavity and neural (Wallerian) degeneration
1 cm cubic infarct takes…to reabsorb
3 months to reabsorb
Axonal swelling manifests largely in what phase?
Subacute
What is a paradoxical finding sometime present in stroke?
Enlargement of LV due to blocked foramen, contributes to mass effect
Duret hemorrhage and outcome
Process of hemorrhage leading to small infarcts or bleeds in midline brainstem region due to downward displacement of brainstem; outcome generally fatal
Important sign of uncal herniation
Blown pupil
Subpial sparing is present in what kind of stroke? Differentiates what?
Small amount of spared tissue near pia present in a cerebral stroke; differentiates stroke from trauma
Most common causes of cerebral and meningeal hemorrhage (4)
Trauma, vascular malformation (berry aneurysm, malformation), blood dyscrasia, arterial changes (hypertension and amyloid angiopathy)
Blood dyscrasia is often seen in what setting and include what thing?
Hospital –> coagulation problem
Arterial changes are chronic/acute
Chronic
Vascular lipohyalinosis (def)
Weakened arterial wall due to long-term hypertension
Charcot Bouchard aneurysm (def). Most common location?
Small aneurysms that arise due to vascular lipohyalinosis; lenticulostriate vessels of basal ganglia
~70% of HT-related hemorrhages are in…
Deep gray matter of cerebral hemispheres
Congophilic angiopathy (def)
Abnormal deposition of amyloid in cortical/leptomeningeal arterioles
Where do we find congophilic angiopathy hemorrhages? What age?
“Lobar” hemorrhages = peripheral cerebral regions; older adults
Two complications of cerebral hemorrhage
- Rupture into ventricular system; 2. Vasopasm leading to secondary infarction
If neither complication happens, what is the resolution of a cerebral hemorrhage? This is unlike…
Slit-like (small) cavity; unlike an infarct, which leads to cystic cavities
Classifications of global brain hypoxia
Stagnant/hypoperfusion (reduced or no flow) or hypoxic/anoxic (reduced or no O2, such as due to CO poisoning)
Global brain hypoxia cause also be… (3)
Anemic (due to a bleed elsewhere), histotoxic (nitrogen “bends”), hypoglycemic
The most important thing to remember in regards to global event?
Selective vulnerability of cells
What cell is damaged most rapidly? Where in particular (3)?
Pyramidal cells; borderzone arterial territories, deep cortical layers (III, V, VI), hippocampus
Describe cellular selective vulnerability
Neurons > oligodendroglia > astrocytes
Brain death begins with…which does what? Then what? What happens to the tissue? Can you recover from brain death?
Diffuse cerebral edema; increased intracranial pressure; blood flow blocked; it begins autolysis (liquefaction); NO
What is the difference between persistent vegetative state and brain death?
Brain death has not happened because it never lost perfusion; vegetative state = spontaneous eye opening, sleep-wake cycles, maintain breathing
Three most common causes of stroke
Cardioembolic (embolism from heart), atherosclerotic, lacunar (small vessel stroke)
Risk factors (5)
Hypertension, heart disease, carotid bruit, diabetes, smoking
Best predictor of stroke
Previous stroke
Leading stroke risk factor for women and modifiable women-specific stroke risk factors
Migraine with aura; oral contraceptives
Ischemic stroke definition and typical cause
Low blood flow to focal part of the brain; thromboembolism
How much stroke is ischemic (%)
85%
Core of stroke…
Does not recover
What region of the stroke may be salvageable?
Penumbra around core; this is why we must treat quickly
What is the border of the stroke called?
Benign oligemia
ACA stroke (arm and leg)
Leg > arm
MCA gives rise to which important distribution? Where?
Lenticulostriate (internal capsule and basal ganglia)
MCA stroke (arm and leg)
Arm > leg
Left (dominant) cerebral hemisphere symptoms (4)
Aphasia, L graze preference (look at stroke), R visual field deficit, R hemiparesis/sensory loss
“Anterior circulation” stroke includes which two artery involvement?
ACA/MCA
Right (nondominant) cerebral hemisphere (4)
R gaze preference (look at stroke), L visual field deficit, L hemiparesis/sensory loss, NEGLECT (L hemi-inattention and anosagnosia)
What is an internal carotid artery occlusion typically preceded by and course of this? What other symptoms (aka, arteries)?
Amaurosis fugax: gray shade dropping over the eye; demonstrates that presence of carotid artery occlusion –> reduced retinal circulation –> blindness (retinal hypoxia); anterior = MCA and ACA symptoms
PCA syndrome (contralateral, dominant, and bilateral)
Contralateral = homonymous hemianopsia w/ macular sparing; Dominant = alexia w/out agraphia; Bilateral = Anton’s syndrome
Brainstem stroke can cause what kinds of paresis/sensory loss
Hemi- or quadri-
Emboli are more frequent in posterior or anterior vertebral circulation?
Anterior
Acute cerebellar infarction: presents as…but one important consideration
Often doesn’t look so bad on presentation; can develop life-threatening edema due to ventricular system/brainstem obstruction
Stroke where causes locked-in syndrome. What vessel?
Pons; basilar artery
Is a persistent vegetative state a coma?
Yes
Lacunar infarcts and locations (4)
Pure motor (posterior IC), pure sensory (thalamus), dysarthria/clumsy hand syndrome (pons), ataxic hemiparesis (plantar cerebellar/corticospinal)
Transient ischemic attack (TIA)
Reversible focal dysfunction defined as less than 24 hours; should initiate stroke therapy (linked to stroke in coming days)
Subarachnoid hemorrhage; symptoms (3)
Bleeding around brain, typically caused by aneurysm; “worst headache of the life,” N/V, neck stiffness
Types of aneurysms (3)
Berry, mycotic (due to infection), Charcot-Bouchard (micro-aneurysms usually in lenticulostriates associated with hypertension)
Berry aneurysms are most commonly found…%
At juncture between anterior communicating and ACA (40%)
Intracerebral hemorrhage most commonly caused by…
Chronic hypertension
Carotid dissection (def)
Two layers of carotid wall separate causing luminal narrowing + formation of blood clot
How to evaluate for tPA…can’t use in what situation? What about platelets?
Hemorrhage; if platelets are less than 100,000, no tPA
General principles of stroke treatment…
- 85% are ischemic, 2. Most caused by clot, 3. Ischemic penumbra = time is brain
tPA timeline
> 3 hours = IV tPA; 3-6 hours = IA tPA; >6 hours = endovascular intervention
Which, IV or IA, is better? IA requires what?
IV; IA requires angiogram
Aspirin is used to prevent…
Recurrent ischemic strokes
What’s a good pneumonic for remembering what limb ACA and MCA have a preference for?
Alma (like alma mater) = anterior leg, middle arm
