Cerebrovascular Flashcards
What level of cerebral blood flow causes an infarction almost regardless of its duration?
Below 10-12 ml/100g/min
What is the usual level of cerebral blood flow?
55ml/100mg/min
12-23 slow EEG
What molecular mechanisms lead to cell death in ischemia?
- Failure of ATP
- Free radical formation
- Excitatory neurotransmitters
- Failure of ATP production –> lactic acid accumulation
- Formation of free radicals –> peroxidation and disruption of the outer cell and mitochondrial membranes
- Glutamate and aspartate releaed by ischemic cells cause intracellular influx of Na and Ca
What are Hollenhorst plaques?
Crystalline cholesterol sloughed off from an atheromatous ulcer
What is the size range of the arteries occluded in lacunar strokes? And what is the size range of the cavities that they produce?
50-200 microns
3-15 mm in diameter
What are the 3 kinds of lacunar infarctions?
- Fibrohyaloid arteriolar sclerosis
- Atherosclerosis of a large trunk vessel that occludes the origin of these same vessels
- Emboli of small arteries
List the most common location of lacunes in descending order of frequency
- Putamen and Caudate nuclei
- Thalamus
- Basis pontis
- Internal capsule
- Deep in the central hemispheral white matter
Mnemonic: Going down then going up
COMPARE WITH MOST COMMON LOCATION FOR ICH:
- Putamen and adjacent internal capsule 50%!
- Lobar hemorrhage!!!!
- Thalamus
- Cerebellar hemisphere
- Pons
Mnemonic: Just going down
What locations are associated with the following lacunar stroke syndromes?
- Pure motor hemiplegia
- Pure sensory stroke
- Clumsy hand-dysarthria
- Ipsilateral hemiparesis-ataxia
- Internal capsule or adjacent corona radiata
- Lateral thalamus or adjacent parietal white matter
- Paramedian midpons on the opposite side of the clumsy hand
- Pons, midbrain, internal capsule
How to differentiate pontine lacune from supratentorial lacune?
Sparing of the face and the presence of ipsilateral paresis of the conjugate gaze
According to the NASCET and ECST what degree of stenosis necessitates carotid endarterectomy?
70-80%
What is the most common symptom of hyperperfusion syndrome from carotid endarterectomy?
Unilateral severe headache
Other: Headache, Focal deficits, Seizures, Brain edema, Brain hemorrhage
T or F: Asymptomatic carotid stenosis of more than 60-70% in men may benefit from sugery in terms of stroke reduction.
T
What percentage of embolic infarcts develop seizures?
10
What is AKA arteriosclerosis dementia?
Binswanger subcortical leukoencephalopathy
How much stroke is prevented by atorvastatin according to the SPARCL trial?
3%
What is the Raeder syndrome?
ICA dissection syndrome composed Ipsilateral Horner syndrome + Unilateral headache
What is the most common origin of vertebral artery dissection?
C1-C2 where it is mobile but tethered
What arterial dissection can cause SAH?
Vertebral artery
What are the two components of Moyamoya?
- Cerebral rete mirabile: small anastomotic vessels around and distal to the circle of Willis
- Segmental stenosis or occlusion of the terminal intracranial parts of both internal carotid arteries
What are the 3 main components of Binswanger disease?
Dementia, pseudobulbar state, gait disorder
What are the top differentials for ischemic stroke in the young?
Dissection
Drugs (Contraceptives and Shabu)
APAS
PFO
What is the hispathology of the thrombotic vessel in a patient with a stroke?
Nodular intimal hyperplasia of eccentric distribution with increased mucopolysaccharides and replication of the internal lamina
What percentage of primary intracerebral hemorrhages are multiple?
2%
What are the most common sites for hypertensive hemorrhages?
- Putamen and adjacent internal capsule 50%!
- Lobar hemorrhage!!!!
- Thalamus
- Cerebellar hemisphere
- Pons
COMPARE WITH MOST COMMON SITES FOR LACUNAR INFARCTION
- Putamen and Caudate nuclei
- Thalamus
- Basis pontis
- Internal capsule
- Deep in the central hemispheral white matter
What is the spot sign?
Appearance of contrast within the hemorrhage during the CT angiography, associated with a high rate of hematoma expansion
What part of the hematoma causes it to become bright on T1 and dark on T2?
Formation of deoxyhemoglobin and methemoglobin
What is the term used to describe the arteriolar wall in hypertensive patients with bleeds?
Segmental lipohyalinosis
Primary HTN hemorrhages are also associated with the flase aneurysm Charocot Bouchard
What is the risk of rupture for unruptured aneurysms?
25mm 10%
Identify which age period the following CVD occur:
- MELAS
- etat marbe: Cardiorespiratory failure and generalized ischemia
- Binswanger disease
- Unilateral cerebral infarction
- Infancy and childhood
- Perinatal and postnatal circulatory disorders
- Late Adult
- Prenatal
What component of the LP conferes the most risk for stroke?
LDL followed by TG
What are the top 3 sites for atheromatous plaques?
- ICA at the origin from the common carotid artery
- cervical part of the vertebral arteries at the junction to form the basilar
- in the stem or at the bifurcation of the MCA
- Proximal PCA
- Proximal ACA
What is a more common cause of stroke atherothrombosis or embolism?
Embolism
What is the critical residual lumen in the ICA before stroke occurs?
<2mm (Normal size is 5-10mm of the ICA)