Ischemic Stroke

Question 1

What is the difference between a stroke and a TIA?

Answer 1

TIA- the symptoms last less than 24 hours

Question 2

What are the most likely cause of large vessel occlusion?

Answer 2

thromboembolism from heart or aortic arch. Atherosclerotic rupture in the internal carotid- may even break off an embolus

Question 3

What are some of the causes of small vessel occlusion

Answer 3

Lose penetrating arteries- lipohyalinosis, small vessel thrombosis, dissection of artery causing occlusion or creating embolus to the brain, vasospasm frum drug, infection, HTN, irritation of the artery

Question 4

What are the symptoms of large vessel stroke?

Answer 4

Multiple systems affected

Question 5

What are the symptoms of large vessel stroke?

Answer 5

Single system affected- hemiparesis or hemisensory loss

Question 6

What does occlusion of MCA cause?

Answer 6

hemiparesis, hemsensory deficit, hemianopsia, aphasia (dominant)

Question 7

What are treatable risk factors for ischemic stroke?

Answer 7

Hypertension
Lipid Disorders
Homocysteine Elevations (?)
Smoking
Obesity
Diabetes

Question 8

What is the benefit of statins in preventing stroke?

Answer 8

cause release of NO

Question 9

What treatment can be used for insulin resistance (HOMA test)?

Answer 9

Pioglitazone

Question 10

What are some less common mechanisms of stroke?

Answer 10

fibromuscular dysplasia, moya-moya disease (overly thickened vessels), spontaneous arterial dissection

Question 11

What are hematological issues that cause stroke in young patients?

Answer 11

Protein C, Protein S, Antithrombin, Factor V Leiden, Prothrombin Gene, etc...all venous risks with unclear arterial risk
SSA, very tiny risk, if any, for SST
Malignancies (Noble still waiting…)
Oral Contraceptives, Post Partum
Anti-Phospholipid Antibody Syndrome

Question 12

What are some other factors that contribute to stroke?

Answer 12

Alcohol Abuse (not use...)
Stimulant Abuse (use?)
Physical Inactivity/Obesity
Congenital Hearts
PFO/ASD/VSD
Acquired Cardiacs: CHF, Valvular, A-Fib, Myxoma.....

Question 13

What is the main cause of CNS vasculitis?

Answer 13

Varicella Zoster virus, also meningitis

Question 14

When are you at highest risk for superior sagittal thrombosis?

Answer 14

day 3 postpartum

Question 15

What are the treatments for stroke

Answer 15

Add any Anti-platelet agent
ASA
Clopidogrel/Ticlopidine/Prasugrel
ASA/Dipyridamole
ASA/Clopidogrel
Or, Add an Anticoagulant
A-Fib
Mechanical Valves
CHF?
Short Term Thrombus in artery, Dissection

Question 16

What do you do for acute treatment?

Answer 16

TPA up to 4.5 hours and IA up to 6 hours

Question 17

Recognize the general presentation of a large vessel or small vessel ischemic stroke and Transient Ischemic Attack (TIA).

Answer 17

large vessel ischemia due to the partial or complete occlusion of a major artery leads to multiple affected systems
small vessel ischemia create lacunar infarcts to due to occlusion of the small penetrating vessels that arise from large arteries deep into the brain, leading to isolated motor or sensory loss on one side.
Transient Ischemic Attacks are neurological deficits that have completely resolved by 24 hours.

Question 18

Discuss the non-atherosclerotic causes of stroke in a young patient

Answer 18

Vasculopathies:

• Fibromuscular Dystrophy: usually in women in their 30s or 40s. Hypertrophy of the smooth muscle in the media of vessels. Typically involves renal artery, but may also include vertebral and carotid. Also associated with arterial dissection and intracranial saccular aneurysms
• Moya-Moya: children, women in their 30s or 40s, and elderly (especially Asian and African-American) get focal occlusion in the middle cerebral artery due to intimal hyperplasia. In elderly it can be HTN or hyperplasia. Also associated with arterial dissection and saccular aneurysm in young people. EBV has been associated with Moya-Moya
• Spontaneous Arterial Dissection: Typically well tolerated, however emboli can form, break off, and occlude distal arteries. Therapy is with anticoagulation until the dissection heals, although intra-arterial stenting or surgery can have a role.

Hematological Disorders

• Deficiencies of protein C, Protein S, or Antithrombin
• Factor V Leiden and Prothrombin
• Thrombosis from PFO/ASD
• Malignancies cause hypercoagulable state
• Sickle Cell Anemia
• Hyperviscosity states: Protein, elevated hematocrit (60%), thrombocytosis (1,000,000), etc. can generate slowness of flow beyond the pump & pipes ability to compensate
• OCP
• Antiphospholipid antibodies

Inflammatory Mechanisms:

• Vasculitis- In the CNS, may be associated with VZV
• Migraine- can cause stroke through vasospasm or increased platelet aggregation

Venous Infaction: Usually due to trauma. Can also be from dehydration, CNS infection, hypercoagulable states. Think of post-partum sagittal sinus thrombosis.

Vasospasm

Question 19

Discuss the basic principles of emergency treatment of ischemic stroke

Answer 19

Treat HTN only if very severe, Rehydrate, TPA within 3 or 4.5 hours, give glucose only if hypoglycemic

Question 20

Discuss how to modify metabolic, lifestyle, and structural risk factors for stroke.

Answer 20

“good health” approach (sleep, eat healthy, exercise, fitness, low stress, high happiness) as well as specific dietary, vitamin and medication therapies where needed.
The single agents that reduce the long term risk of recurrent ischemic stroke are aspirin, Thienopyridines (Clopidogrel, Prasurgrel, Ticlopidine) and Anticoagulants. Endarterectomy was highly beneficial in symptomatic
patients with high grade (70-90%) stenosis.

Question 21

Discuss the importance of mechanism of stroke in both resuscitation and prevention

Answer 21

Ischemic stroke can be resuscitated with thrombolytic agents (i.e. Tissue Plasminogen Activator or TPA) given IV or by IA catheter as long as you get this done within 4.5
hours or perhaps longer in highly selected cases. Keeping fluids up, maximizing cardiac output, and resisting the temptation to lower blood pressure (i.e. stepping on the fire hose) help, too. Research into the use of mechanical IA techniques (grab the embolus, fracture it, angioplasty, stenting, etc.), hypothermia, and neuro-protective drugs continues.