Cerebrovascular Accident

Question 1

What is a cerobrovascular accident?

Answer 1

Acute neurological deficit due to ischemia.

Question 2

What are the two types of CVA? Explain them. Which is more common.

Answer 2

1) hemorrhagic - when a blood vessel supplying the brain is severed
2) ischemic - when a blood vessel supplying the brain is occluded or obstructed by a thrombus or embolus

Ischemic strokes occur more frequently, they make up 80% of CVAs.

Question 3

What are a few modifiable risk factors for CVAs?

Answer 3

• hypertension
• hyperlipidemia
• atherosclerosis
• diabetes mellitus
• smoking

Question 4

What are a few non-modifiable risk factors for CVAs?

Answer 4

• increasing age/blood vessel degeneration
• being male
• prior CVA
• family history of CVA

Question 5

Can the brain make energy anaerobically?

Answer 5

No, it can only make energy using oxygen!

Question 6

Can the brain metabolize lipids or proteins for energy?

Answer 6

No, the brain relies on glucose exclusively.

Question 7

Without oxygen and nutrients, how long can brain cells survive?

Answer 7

Minutes.

Question 8

What is the pathophysiology of an ischemic stroke?

Answer 8

• [small] blood vessel is obstructed/occluded
• this leads to focal ischemia
• this causes infarct to an area of tissue, this area is called the necrotic core and the tissue is permanently lost
• the area around the necrotic core receives inadequate perfusion, the structure is intact but the function is lost, it is not yet necrotic, it is called the penumbra, this tissue is salvageable
• the necrotic core will grow without intervention, if ischemia persists, and the penumbra will become part of the core

Question 9

What is the pathophysiology of a hemorrhagic stroke?

Answer 9

• vessel is severed
• leads to hemorrhage
• leads to brain compression

Question 10

What are the two problems caused by hemorrhagic stroke?

Answer 10

• ischemia

- increased intracranial pressure

Question 11

What causes a hemorrhagic stroke?

Answer 11

• mainly hypertension and ageing (degeneration of blood vessels)
• also aneurysms and tumours (they occupy space and grow, damage blood vessels when they come into contact)

Question 12

What are the complications of hemorrhagic stroke?

Answer 12

coma and death

Question 13

What is a transient ischemic attack?

Answer 13

temporary focal ischemia in the brain that reverses itself, with brief, acute neurological deficit… there is no permanent damage

Question 14

How long does a TIA last?

Answer 14

up to maximum 1 hour, usually a lot less

Question 15

Does a necrotic core develop from a TIA?

Answer 15

No, there is penumbra but no necrotic core.

Question 16

If there is no permanent damaged caused, why do we worry about a TIA?

Answer 16

because it is a warning sign of CVA

Question 17

What are some typical signs and symptoms of CVA?

Answer 17

• some degree of paralysis or paraesthesia on one side of body/ unilateral weakness, numbness in face, arm or leg
• speech altered (problem speaking, not a problem with languate)
• altered vision, usually in one eye

Question 18

How is a CVA diagnosed?

Answer 18

• labs (CBC, INR, lipids)… will also tell us about risk factors (hyperlipidemia) or contraindicate a treatment
• EEG
• MRI/CT

Question 19

How is a CVA treated?

Answer 19

• life preservation, salvage tissue/penumbria
• stat antiplatelet treatment (ex. 160 mg ASA) if ischemic stroke
• tissue plasminogen activator (TPA) for ischemic stroke to break down clot
• treat CV risk factors, ex. statins for hyperlipidemia
• surgery, cerebral angioplasty or carotid endoarterectomy (within 2 weeks)
• prevent recurrence (blood thinners) and extension/complications (increased ICP, aspiration)