15. Ischemic Diagnosis and Management

Question 1

Ischemic stroke definition

Answer 1

Cerebral ischemia >24hrs or

Question 2

Transient ischemic attack

Answer 2

Complete recovery of transient ischemia with transiet episode of neurologic dysfunction. No evidence of infarction usually through MRI

Question 3

Cerebrovascular disease is the _____ leading cause of death in the US

Answer 3

CVD is 4th lading cause of death

Question 4

Which type of strokes are more common: Ischemic or hemorrhagic?

Answer 4

Ischemic

Question 5

Go through the circle of willis

Answer 5

Vertebral arteries give off anterior and posterior spinal arteries, and POSTERIOR INFERIOR CEREBELLAR A (PICA)
Vertebral a. combine to form the basilar a
Basilar gives off ANTERIOR INFERIOR CEREBELLAR A (AICA), pontine arteries, and SUPERIOR CEREBELLAR A.
Basilar a bifurcates into POSTERIOR CEREBRAL A (PCA)
PCA joins anterior circulation via POSTERIOR COMMUNICATING A
INTERNAL CAROTID bifurcates into ANTERIOR CEREBRAL A AND MIDDLE CEREBRAL A (ACA, MCA), (Internal carotid also gives off the opthalmic a and anterior choroidal a)

Question 6

Anterior cerebral artery infarct

Answer 6

Supplies the middle of hemispheres= hemiparesis and hemiparalysis of contralateral side –> legs, maybe arms, SPARES FACE

Question 7

Middle cerebral artery infarct

Answer 7

Supplies the lateral hemispheres and temporal regions = hemiparesis and hemiparalysis of contralateral side –> face, arms, spares legs usually
If on dominant hemisphere –> aphasia (speech and language)

Question 8

Posterior cerebral artery infarct

Answer 8

Supplies the visual cortex (occipital lobe) = visual deficits –> contralateral homonymous hemianopia
If dominant hemisphere involved –> receptive aphasia (fluent aphasia, patients can understand language but cannot express themselves aka sentences they say don’t make sense)

Question 9

Basilar artery infarct

Answer 9

Supplies pons, midbrain, medulla = dizzziness, diplopia, dysarthria (unclear speech), Locked-in Syndrome (person has retained consciousness but are paralyzed except for vertical eye moement), coma and death

Question 10

Carotid TIAs have two forms. What are they, and describe them.

Answer 10

Retinal: carotids supply ophthalmic artery, so emboli can travel into it and impair retinal circulation –> transient blindness in right eye
Hemispheric ischemia: Carotid supplies entire hemisphere of brain; transient weakness or numbness of contralateral side

Question 11

What would a vertebral-basilar TIA present as?

Answer 11

Transient dysfunction of brainstem –> slurred speech, difficulty swallowing, altered consciousness
Basilar artery also supplies occipital lobe –> visual defects

Question 12

Can TIAs progress to strokes?

Answer 12

YES, TIAs can lead to strokes

Question 13

How do you assess for the risk of TIA progressing to a stroke?

Answer 13

Use the ABCD2 criteria:
Age: > 60
BP: > 140 sys, > 90dia
Clinical features (2pts): weakness, speech impairment
Duration: > 60mins = 2pts, 10-59mins = 1pt
Diabetes

If pts > 3, ADMIT THE PATIENT

Question 14

Tx for TIA

Answer 14

Anticoagulants: Heparin and coumadin

Profess trial: Plavix (clopidogrel) is better; reduced hemorrhage risk

Question 15

What is important about taking ASA + Plavix?

Answer 15

ASA + Plavix is for short-term use: 90 day max in high risk patients (much higher risk of bleeding afterwards)

Question 16

What anticoagulants may be used in addition to warfarin with a cardioembolic TIA?

Answer 16

Dabigatran, rivaroxaban, apixaban

Question 17

What are the surgical treatment(s) for TIA? Which is better?

Answer 17

Carotid endarterectomy, carotid stenting

Endarterectomy better because it has a lower peri-operative stroke risk than carotid stenting

Question 18

When do you use surgical methods vs medical methods for carotid TIAs?

Answer 18

Surgical: >70% stenosis
Medical:

Question 19

Auscultation of carotid bruits: Why are they not done with assymptomatic people?

Answer 19

They are not done because the chance of a benefit from surgical intervention is lower than chance of harming patient

Still want to listen though because it may tell you about vascular disease elsewhere in the body

Question 20

Patient comes in and has no neurological deficits and no h/o transient neurologic episodes in the past. Do you listen to carotid bruits?

Answer 20

Yes, but only to see if there may be vascular disease elsewhere in the body. DO NOT use this as a guideline to go for a carotid endarterectomy

Question 21

In what situation would a watershed infarct occur?

Answer 21

When you have a patient with HTN and you make them acutely hypotensive –> not enough perfusion to the tissues

Ischemia at border zones of vascular territories (MCA - ACA; MCA - PCA)

Question 22

What is ischemic penumbra

Answer 22

area surounding ischemic tissue –> may be viable due to collateral circulation but can die w/o tx

Question 23

Acute ischemic stroke - tx

Answer 23

Give anti-HTN meds if systolic BP > 220 (don't want to lower too much because compromise penumbra)
Tx hyperglycemia (inc. lactic acid --> inc. ischemia) and hyperthermia (inc. metabolic demands of tissue)

Question 24

Embolic infarction tx

Answer 24

Anticoagulation

If on warfarin, can give them tPA

Question 25

What are the differences in treatment based on the results of a CT scan for an infarction?

Answer 25

CT scan – no blood, no significant infarct: Start heparin, then put them on long-term coumadin
CT scan – blood, large deficit: Delay anticoagulation therapy for 1-2weeks (can use ASA in meantime), then place them on long-term coumadin. This reduces the chance that they hemorrhage on anti-coagulants due to the severeness of their infarct

Question 26

What does a lacunar infarct present as when it is located in:

1. internal capsule
2. thalamus
3. basis pontis

Answer 26

1. motor hemiparesis
2. hemisensory deficit
3. ataxia hemiparesis, clumsy hands, dysarthria

Question 27

Tx for lacunar infarct

Answer 27

antiplatelet therapy, aggressive control of BP after acute phase

Question 28

What are the contraindications for thrombolytic therapy

Answer 28

Intracranial hemorrhage
Uncontrolled HTN (SBP > 180)
Coagulopathy

Question 29

Do you give IVtPA to a patient that is going to receive endovascular therapy?

Answer 29

Yes

Question 30

AHA guidelines for prevention of second stroke

Answer 30

Anti-HTN tx
Smoking cessation
Limit alcohol intake
Weight loss (BMI between 18-25)
Manage DM
30 mins of exercise on most days, DASH diet, Mediterranean Diet

Question 31

AHA guidelines in regards to statins

Answer 31

Give statins to reduce stroke recurrence regardless of presence of CHD or hyperlipidemia

Question 32

What level should you get to for the amount of LDL in blood for preventing another stroke?

Answer 32

50% reduction in LDL-C or to >70mg/dL