NAPLEX 2026 - Stroke

Stroke occurs when _________.

Blood flow to an area of the brain is interrupted

What is an acute ischemic stroke caused by?

Thrombus (localized clot) that forms during a cerebral atherosclerotic infarction (non-cardioembolic: origin is in the brain)

Embolus (clot) that forms in the heart and travels to the brain (cardioembolic stroke: origin is the heart)

What is a hemorrhagic stroke? What are the two types?

A stroke caused by bleeding into the brain

Intracerebral hemorrhage (ICH)

Subarachnoid hemorrhage (SAH)

What is a transient ischemic attack (TIA)?

"Mini stroke"

Temporary clot and blockage of blood flow in the brain

Often a warning sign for acute ischemic stroke

What are the modifiable and non-modifiable risk factors for stroke?

Modifiable:

- hypertension (most important)

- atrial fibrillation

- dyslipidemia

- diabetes

- physical inactivity

- smoking

Non-modifiable:

- prior stroke or TIA

- advanced age ( > 80)

- race (higher risk in African Americans)

- genetic diseases (sickle cell)

What are the signs and symptoms of stroke?

ACT F.A.S.T

Face dropping (uneven)

Arm weakness (one arm)

Speech difficulty

Time to call 911

Brain imaging using _____ is ideally performed within _______ of arrival to the ED to quickly identify whether the stroke symptoms are due to a hemorrhage.

CT

20 minutes

What is the immediate goal of treatment for ischemic stroke?

Restore blood flow

Alteplase mechanism of action

Recombinant tissue plasminogen activator

Binds to fibrin in a clot and coverts plasminogen to plasmin, resulting in fibrinolysis

Patients are candidate for alteplase therapy if:

No bleeding seen on imaging

Stroke symptom onset is

What conditions and drugs increase bleeding risk and are contraindications to alteplase?

Active internal bleeding (ICH)

Risk of internal bleed due to:

- severe hypertension (> 185/110): if this is the only CI then BP should be lowered with IV meds before giving alteplase

- other conditions (head trauma)

- labs (elevated INR, low platelets)

- drug interactions (anticoagulant use)

What is the dosing for alteplase?

0.9 mg/kg

Max dose: 90 mg

Hypertension treatment is often initiated after the first several days following a stroke. Which medications have the best evidence for stroke risk reduction?

Thiazide diuretics

ACEi

ARBs

For patients with non-cardioembolic ischemic stroke or TIA, what is recommended to reduce the risk of recurrent stroke, MI, or death?

Antiplatelet therapy with aspirin, aspirin/ER dipyridamole, or clopidogrel

Prasugrel is CI in anyone with history of TIA or stroke

Combination therapy with clopidogrel and low-dose aspirin can be initiated within 24 hours of a minor ischemic stroke (NIHSS score

21-90 days

Do not use combination therapy long term for secondary prevention as it increases the risk of hemorrhage

Follow combination treatment with anti platelet monotherapy indefinitely

What is the primary complication of an ICH?

Increased intracranial pressure

What can be used to lower ICP?

Elevating the head of the bed at least 30 degrees

Administering IV osmotic therapy with either hypertonic saline or mannitol

What can a SAH result from?

Cerebral aneurysm rupture that results in a severe headache

Cerebral artery vasospasm can occur ________ after the bleed. What can improve outcomes associated with vasospasm induced ischemia?

3-21 days

Oral nimodipine x 21 days

Nimodipine mechanism of action

DHP CCB that is more selective for cerebral arteries due to increased lipophilicity

Only indicated for SAH, not used as an anti hypertensive treatment

Nimodipine boxed warning

Do not administer IV or by other parenteral routes