Ucsf: Video E 41 Part 1 Stroke

Front 1

What are 5 early signs of an acute stroke

Back 1

loss of gray white matter diff (logwmd)
cortical (insular) ribbon sign- (logwmd)
basal ganglia edema (logwmd)
dense artery sign

Front 2

What is the cortical ribbon sign

Back 2

this is loss of grey white differentiation of the insular cortex (the insular ribbon)

Front 3

When does the cortical (insular) ribbon sign occur

Back 3

MCA infarct

Front 4

When does basal ganglia edema occur

Back 4

if the infarct is in the proximal segment of the MCA

Front 5

What does effacement mean

Back 5

there is edema and the cortical sulci are not well seen

Front 6

What does the insular (cortical) ribbon sign and the basal ganglia edema look like

What is the lentiform nucleus

Back 6

Edema of the basal ganglia and/or insular cortex. The involved lentiform nucleus will appear hypodense with indistinct lateral border. The insular cortex will appear swollen compared to the contralateral side and there will be loss of the grey white differentiation of the insular ribbon

putamen and the globus pallidus .

Front 7

What percent of MCA strokes have a dense artery sign

Back 7

30

Front 8

When does hypodensity start to appear following a cerebral infarct

Back 8

6h

Front 9

What MR sequence has similar timing to the non-contrast CT

Back 9

flair/T2

Front 10

What is the signal of infarct on flair imaging

Back 10

bright

Front 11

What is flair similar to

Back 11

T2 with out bright CSF

Front 12

What MR sequence will show infarct earliest

Back 12

DWI

Front 13

What are the 2 diffusion sequences

Back 13

DWI and ADC

Front 14

When there is bright signal on the DWI sequence what should be look at next

Back 14

the ADC for a dark signal in the same area if there is an acute stroke

Front 15

What does it mean if there is increased signal on the T2 and DWI but no dark signal on the ADC map

Back 15

T2 shine through

Front 16

What does T2 shine through indicate

Back 16

chronic changes

Front 17

Is the DWI (bright) and ADC (dark) maps useful to determine if a stroke is acute

Back 17

yes

Front 18

What MR sequences does the a non-contrast CT correspond with in terms of timing

Back 18

flair and T2 (become bright)

Front 19

What is the signal characteristic of decreased diffusion on DWI and ADC

Back 19

DWI- bright
ADC- dark

Front 20

What happens to the DWI beyond 2 weeks following an acurte stroke

Back 20

it becomes dark in that area indicating increased diffusion.

Note: ADC will become bright

Front 21

How does evaluation of a pneumbra work with MR

Back 21

DWI will show an area of bright signal representing infarcted area and a PWI will show an area of ischemic area which may be larger and if so; the area that they dont match the pneumobra

Front 22

When is the T1 with Gadolium useful for evaluating a stroke

Back 22

around 2 weeks because there is psuedo-normalization of DWI at that time as it moves from bright to dark

Front 23

What is typical of a subacute stroke in post-contrast CT

Back 23

cortical gyriform enhancement

Front 24

If the face or the arm is affected what is the likely location of the stroke

Back 24

MCA

Front 25

If only the leg is affected what is the most likely affected area

Back 25

ACA

Front 26

What if the face, the arm and the leg are affected

Back 26

look for a stroke in the internal capsule along the CST

Front 27

What segment of the MCA artery do lenticulostriate arteries arise

Back 27

the M1 segment

Front 28

What part of the brain is affected by the lenticulostriate arteries

Back 28

basal ganglia

Front 29

What part of cerebral circulation supplies the thalamus

Back 29

the posterior cerebral artery

Front 30

What does the posterior cerebral artery supply

Back 30

thalamus, mesotemporal lobe, occipital lobe

Front 31

Is any of the PCA terittory above the level of the ventricle

Back 31

no

Front 32

What may cause increase signal on DWI in the mesotemporal lobe but exclude the thalamus or any other part of the PCA territory. Note this can be confused with a stroke.

Back 32

herpes encephalitis

Front 33

What artery supplies the posterior fossa

Back 33

the basilar artery

Front 34

If there is a dense basilar artery sign what areas will be affected

Back 34

the bilateral cerebellum hemisphere and the pons

Front 35

Can a basilar artery occlusion cause infarct in parts of the occipital lobe

Back 35

yes

Front 36

Can the post contrast CT look normal if there is a dense artery sign.

Back 36

yes

Front 37

Why is a CTA able to detect a dense artery sign (as a filling defect) while the post contrast may miss this finding

Back 37

because concentration of the contrast is decreased because more time is allowed for the contrast in a post contrast to dilute and match the concentration of the clot so when you window the CT it is more difficult to see on post contrast CT. IN

Front 38

What 3 areas does the anterior choroidal artery supply

Back 38

the amygdala and the hippocampus (anterior to the PCA territory of the mesotemporal lobe)
internal capsule

Front 39

What level does the anterior choriodal artery go to

Back 39

not above the ventricle

Front 40

What is the artery involved when there is symptomology involving the face, arm and leg on one side

Back 40

anterior choroidal artery

Front 41

What is the time limit to decide weather or not to give TPA

Back 41

3h

Front 42

What is the maximum amount of brain that can be involved and still can give tpa

Back 42

up to 1/3rd of the brain

Front 43

What should be suspected if there are multiple bilateral infarcts

Back 43

an embolic orgin from the heart

Front 44

Where are the water shed areas below the level of the ventricle

Back 44

posteriorly at the junction of the MCA and PCA territory

Front 45

Where are the water shed areas above the level of the ventricle

Back 45

at the junction of the MCA and ACA

Front 46

What is the cause of watershed infarction

Back 46

decreased cardiac output

Front 47

What is the best MR sequence to analzye a carotid artery dissection

Back 47

axial T1 fat sat

Front 48

What is the sign for an arterial dissection on MR

Back 48

crescent sign

Front 49

What forms the peripheral part of the crescent sign

Back 49

methemeglobin in the wall which is bright, The flowing blood in the middle is dark bc of flow void

Front 50

Where is the distal type of carotid dissection located

Back 50

mid to distal ICA

Front 51

Is there a false lumen in the distal type of carotid dissection

Back 51

no

Front 52

Is the carotid bulb spared in the distal type of carotid dissectin

Back 52

yes, the carotid bulb is spared

Front 53

What is the cause of a distal type of carotid artery dissection

Back 53

subintimal hematoma

Front 54

Is the patient always symptomatic with the distal type of carotid artery dissection

Back 54

yes

Front 55

What are the characteristics of a distal type of carotid artery dissection
5

Back 55

mid to distal ICA which spares the carotid bulb
subintimal hematoma with no false lumen
pts will be symptomatic

Front 56

What are the 5 layers of the blood vessel

Back 56

tunica intima
internal elastic lamina
tunica media
external elastic lamina
tunica externa

Front 57

What are the 2 tyeps of carotid artery dissections

Back 57

distal and proximal

Front 58

What is the cause of a proximal carotid dissection

Back 58

progression of an aortic aneurysm

Front 59

What part of the carotid artery is affected by a proximal carotid dissection

Back 59

cca

Front 60

Is ICA extension common with proximal artery dissection

Back 60

no

Front 61

Can these patiens with proximal artery dissection be asymptomatic

Back 61

yes they may be symptomatic or asymptomatic

Front 62

Which one has a false lumen a proximal or distal carotid artery dissection

Back 62

proximal artery dissection has a false lumen

Front 63

What are 5 characteristics of a proximal carotid artery dissection

Back 63

progression of an aortic dissection in to the common carotid artery which usually spares the ICA.
False lumen
asymptomatic or symptomatic

Front 64

Does the false lumen ever fill with contrast in a proximal carotid artery dissection

Back 64

yes, sometimes

Front 65

When looking at an MR of the neck should you always look for filling defects of the arteries

Back 65

yes, if you see bright signal it may represent methemeglobin and a dissection (on T1)

Front 66

What does a superior sagital sinus thrombosis look like on CT

Back 66

a dense sinus

Front 67

What does a superior sagital sinsus thrombosis look like on a venogram/post contrast CT

Back 67

empty delta sign (corresponds with the clot causing a filling defect)

Front 68

Does a venous infarct typically cause areas of hemorrhage

Back 68

yes, patchy areas of hemorrhage, or ischemic stroke

Front 69

If the superior sinsus or cortical vein is thrombosed where do the infarcts typically occur

Back 69

the posterior parietal lobes

Front 70

If the straight sinus and internal cerebral veins are thrombosed where do the infarcts typically occur

Back 70

bilateral thalamus

Front 71

If the transverse sinus is thrombosed where do the infarcts typically occur

Back 71

temporal lobe

Front 72

What are 2 causes of a transverse sinus thrombosis

Back 72

trauma or otitis-mastoiditis

Front 73

What are the signs of cavernous sinus thrombosis

Back 73

same as a cc-fistula
proptosis, dilations of superior optic vein, convex appearance of cavernous sinus, enlargement of optic muscles

Front 74

What is the different findings of a cavernous sinus thrombosis and a cc-fisutula

Back 74

there will not be enhancement of the cavernous sinus