022715 cerebrovascular dis

Question 1

primary motor cortex–homunculus

Answer 1

from medial to lateral: leg/foot, trunk, arm, hand, face

Question 2

primary visual cortex is supplied by what artery

Answer 2

PCA

Question 3

lenticulostriate arteries come off what main artery

Answer 3

MCA

Question 4

hypoxia

Answer 4

deprivation of O2
occurs through:
-low level of O2 in blood (respiratory arrest, near drowning, severe anemia, CO poisoning)
-low blood flow to tissue/ischemia (cardiac arrest, vessel obstruction, increased intracranial pressure)
-oxygen utilization by tissue is impaired (cyanide poison)

Question 5

ischemia

Answer 5

low blood flow

Question 6

global ischemia

Answer 6

systolic pressure under 50 mmHg

if ischemia is severe, can result in persistent vegetative state or brain death

Question 7

focal ischemia

Answer 7

infarction from obstruction of local blood supply (stroke)

Question 8

most vulnerable cells to hypoxia/ischemia in brain

Answer 8

in decreasing order: neurons, oligodendrocytes, astrocytes

Question 9

most vulnerable regions in brain to hypoxia/ischemia

Answer 9

in decreasing order: hippocampus, lamina 3 and 5 of cerebral cortex (laminar necrosis), Purkinje cells in cerebellum

Question 10

how do acutely hypoxic/ischemic neurons appear?

Answer 10

red cytoplasm

pyknotic cell with shrunken and dark nucleus, no nucleolus visible

Question 11

clinical symptoms of severe global ischemia

Answer 11

persistent vegetative state (unconscious, but w retention of sleep wake cycles, primitive orienting responses, brainstem and diencephalon reflexes)

brain death (diffuse irreversble cortical injury w brainstem injury-absence reflexes and respiratory drive)

Question 12

severe global ischemia–appearance?

Answer 12

non-perfused brain

gross: swollen brain, slit-like ventricles, often has hernations
micro: pallor, vacuolation of parenchyma, sparse eosinohpilic neurons

Question 13

most common sites of thrombosis in brain

Answer 13

carotid bifurcation
origin of MCA
origin or end of basilar artery

Question 14

embolic infarcts are more likely hemorrhagic: true or false

Answer 14

true

Question 15

focal ischemia-causes?

Answer 15

thrombosis
emboli
lacunar infarcts/slit hemorrhages

Question 16

sources of emboli?

Answer 16

cardiac-can throw shower into head 
mural thrombus (MI, valve dis, atrial fib)
endocarditis

non-cardiac:
atheroma
fat, neoplasm, air

Question 17

which artery is most frequently affected by emboli

Answer 17

MCA

Question 18

lacunar infarcts/slit hemorrhages

Answer 18

hyaline arteriolosclerosis caused by HTN and diabetes mellitus

causes lacunes (small ischemic strokes due to vessel narrowing in subcortical brain struc-basal ganglia, internal capsule, thalamus, white matter, pons that may be hemorrhagic)

Question 19

right face, arm, and leg plegia-classic for?

Answer 19

lacunar stroke

Question 20

less common causes of infarction

Answer 20

vasculitis
arterial dissec of carotid arteries
coagulation disorders
microvasculopathy
amyloid angiopathy
drug abuse

you would think of the above in young inddividuals w infarction

Question 21

infarct

Answer 21

lack of O2 due to an obstruction

Question 22

gross exam of infarct

Answer 22

acute (to 48 hrs): soft, swollen, gray-white distinctin blurred

subacute (to 2-3 wks): liquefactive necrosis

chronic (several months): CAVITATED, all dead tissue removed

Question 23

microscopic exam of infarct

Answer 23

acute (8-12 hrs): red neurons, pallor
acute (to 48 hrs): neurophils

subacute (48 hrs to 3 wks): macrophages, necrotic tissue, reactive astrocytes, vascular prolif

chronic (several months): cavity w GLIAL SCAR (astrocytes around edge)

Question 24

vascular dementia

Answer 24

stepwise progression usally from multiple strokes

Question 25

cerebral venous thrombosis

Answer 25

causes hemorrhagic infarcts | usually superior sagittal sinus or lateral sinuses

Question 26

spinal tap can assess for

Answer 26

pressure

Question 27

most common cause of intracerebral hemorrhage

Answer 27

HTN: - peak occurrence in 60s - abrupt onset of severe neuro dysfxn when hematoma is large - PUTAMEN, THALAMUS, PONS, CEREBELLUM - hyaline arteriolosclerosis

Question 28

causes of intracerebral hemorrhage

Answer 28

HTN (most common) vascular malformations amyloid angiopathy

Question 29

vascular malformations-the two most common?

Answer 29

arteriovenous malformation | cavernous angioma

Question 30

arteriovenous malformation

Answer 30

most common vascular malformation presentation btwn 10-30 yrs most often in MCA territory

Question 31

cavernous angioma

Answer 31

cerebellum, pons, white matter evidence of prior bleeding smaller bleed

Question 32

causes of lobar hemorrhage

Answer 32

``` neoplasms drug abse vasculitis hemorrhagic diathesis amyloid angiopathy ```

Question 33

amyloid angiopathy

Answer 33

in elderly, beta amyloid deposition in vessel wall weakens the vessel doesn't happen deep in brain. occurs in hemispheres usually recurrent

Question 34

subarachnoid hemorrhage-causes?

Answer 34

trauma (associated w contusions) | aneurysms (sacculary/berry, mycotic, fusiform)

Question 35

saccular/berry aneurysm

Answer 35

"worst headache ever" increased risk w HTN, smoking, AVM DEFECT IN MEDIA IS COGENITAL and aneurysm develops over time occur usually at branch points, 90% in anterior circulation

Question 36

types of hemorrhagic stroke

Answer 36

intracerebral | subarachnoid

Question 37

difference btwn hemorrhagic stroke and intracerebral hematoma?

Answer 37

hemorrhagic stroke has ischemic insult

Question 38

hemorrhagic infarct vs intracerebral hemorrhage?

Answer 38

in intracerebral hemorrhage, the ruptured blood vessel is the primary reason for bleeding in hemorrhagic infarct, there's a blockage of the blood vessels and then blood returns and goes into the space