B7.059 Stroke

Question 1

incidence of stroke in the US

Answer 1

1 mil new cases yearly
#3 cause of death
6 mil stroke survivors at high risk of recurrence

Question 2

what is a stroke

Answer 2

sudden onset of focal brain deficits

usually from blockage or rupture of a cerebral blood vessel

Question 3

3 common causes of ischemic stroke

Answer 3

atherosclerosis (large vessels)
cardiogenic
small vessel disease (lacunes)

Question 4

types of strokes caused by atherosclerosis

Answer 4

artery to artery emboli

stenosis (less common)

Question 5

primary cause of cardiogenic emboli

Answer 5

a-fib

Question 6

small vessel disease processes

Answer 6

lipohyalinosis

microatheroma

Question 7

toast classification of stroke causes

Answer 7

85% infarction:
-20% cardiogenic
-25% atherosclerotic
-20% lacunes
-30% cryptogenic
-5% unusual
15% hemorrhage:
-intracerebral
-subarachnoid

Question 8

mechanism of cardiogenic emboli

Answer 8

emboli from heart become lodged in cerebral blood vessels

typically red clot

Question 9

diagnosis of cardiogenic stroke

Answer 9

identify source

• continuous EKG (look for a-fib)
• trans thoracic echo
• trans esophageal echo

Question 10

common sources of cardiogenic embolism

Answer 10

nonvalvular a-fib- 45%
acute MI- 15%
prosthetic valves- 10%
rheumatic heart disease- 10%
ventricular aneurysm- 10%
uncommon source- 10%

Question 11

treatment of cardiogenic ischemic strokes

Answer 11

aimed at prevention of future strokes

• anticoagulation
• watchman device
• exception: endocarditis, treat underlying cause w antibiotics (infective) or immunosuppressive agents (marantic)

Question 12

anticoagulation options for cardiogenic strokes

Answer 12

warfarin (INR 2-3 for a-fib)
monoclonal Abs
-apixaban
-edoxaban
-dabigatran
-rivaroxaban

Question 13

anticoagulation therapy in stroke prevention in a-fib

Answer 13

very effective

warfarin: 65% risk reduction
dabigatran: 75% risk reduction

Question 14

why choose dabigatran over warfarin?

Answer 14

easier

decreased risk of intracranial hemorrhage

Question 15

diagnosis of an atherosclerotic stroke

Answer 15

large vessel stroke plus:
1. evidence of atherosclerosis on imaging
OR
2. risk factors for atherosclerosis

Question 16

imaging for atherosclerosis

Answer 16

carotid duplex
CT angio
MR angio
catheter angio

Question 17

risk factors for atherosclerosis

Answer 17

in order of importance:

1. age
2. HTN
3. smoking
4. DM
5. hyperlipidemia

Question 18

secondary prevention for atherosclerotic stroke

Answer 18

risk factor control
antithrombotic (usually antiplatelet)
carotid artery stenting or endarterectomy

Question 19

speak to risk factor control for prevention of atherosclerotic stroke

Answer 19

most important are HTN and smoking
improvement of DM control does not decrease stroke risk, but is worthwhile for other causes
hyperlipidemia control more important for coronary artery disease

Question 20

lipids and stroke prevention

Answer 20

hyperlipidemia not well established risk factor

stroke risk decreased in patients with diabetes, CHD, and PVD treated with statins

Question 21

effect of DM on stroke risk

Answer 21

increases stroke risk 2-4x
synergistic with other risk factors (HTN, hyperlipids)
tight glucose control doesn’t have proven benefit for stroke

Question 22

antithrombotic agents for atherosclerotic stroke

Answer 22

1. aspirin
2. clopidogrel
3. dipyridamole
   - DO NOT use warfarin, similar effectiveness to aspirin with much higher bleeding risk
   - aspirin typically used

Question 23

does intracranial artery stenting work?

Answer 23

no, more damage than benefit

can dislodge additional emboli during procedure which can cause new strokes

Question 24

when should carotid endarterectomy. stenting be considered

Answer 24

symptomatic, high grade stenosis
risk of perioperative MI and stroke too high to justify surgery in most asymptomatic patients and patients with moderate stenosis

Question 25

mechanism of lacunar strokes

Answer 25

penetrating artery occlusion via lipohyalinosis or microatheroma

Question 26

lipohyalinosis

Answer 26

HTN and DM causes necrosis and hyalinization of small vessels that can lead to occlusion

Question 27

risk factors for small vessel disease

Answer 27

``` age HTN DM hyperlipidemia smoking ```

Question 28

diagnosis of lacunar infarcts

Answer 28

clinical syndrome: will see subcortical signs without cortical findings MRI confirmation (misses 25%) risk factors: HTN, DM

Question 29

pure motor hemiparesis lacunar syndrome

Answer 29

localization to the posterior limb of the internal capsule, basilar pons

Question 30

ataxia-hemiparesis lacunar syndrome

Answer 30

localization to the internal capsule, basilar pons

Question 31

dysarthria-clumsy hand lacunar syndrome

Answer 31

localization to the anterior limb of the internal capsule, basilar pons

Question 32

pure sensory lacunar syndrome

Answer 32

localization to the thalamus

Question 33

prevention of recurrence of lacunar strokes

Answer 33

poorly studied risk factor control: HTN. DM antiplatelets assumed to be effective NO operative intervention

Question 34

unusual causes of stroke

Answer 34

``` arterial dissection (spontaneous, traumatic) drugs of abuse (coke, meth) ```

Question 35

potential cryptogenic causes of stroke

Answer 35

hypercoagulable states patent foramen ovale monitor long term for a-fib

Question 36

why might patent foramen ovale cause stroke

Answer 36

fibrous adhesions fail to seal the atrial septum after birth (occurs in 25% of people) persistence of a potential shunt between the R and L atria paradoxical emboli

Question 37

acute treatment of ischemic stroke

Answer 37

IV alteplase (TPA) catheter thrombectomy must have excellent multidisciplinary system of care in place

Question 38

IV alteplase (TPA)

Answer 38

up to 4.5 hours after onset effect for all ischemic stroke subtypes intracerebral hemorrhage NNT8

Question 39

catheter thrombectomy

Answer 39

up to 24 hr after onset only effective in proximal large vessel occlusion intracerebral hemorrhage NNT 2

Question 40

2 types of spontaneous intracranial hemorrhage and their causes

Answer 40

1. intracerebral - hypertensive - amyloid angiopathy - coagulopathy 2. subarachnoid - ruptured berry aneurysm - thunderclap headache

Question 41

locations of intracerebral hemorrhage by subtype

Answer 41

hypertensive: subcortical -thalamus -cerebellum -pons -BG amyloid angiopathy: lobar

Question 42

2 types of vascular dementia

Answer 42

1. history of clinical strokes correlated with onset of cognitive deficits 2. no history of clinical strokes by diffuse subcortical vascular disease on imaging * * both have a subcortical dementia pattern aka abnormal elementary neuro exam