Stroke Quiz: Mechanisms and Types

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Questions and Answers

Which of the following is NOT a branch of the internal carotid artery?

Posterior Communicating

Middle Cerebral

Anterior Spinal (correct)

Ophthalmic

What is the primary reason for the higher fatality rate of hemorrhagic strokes compared to ischemic strokes?

Hemorrhagic strokes involve a sudden loss of blood supply to the brain.

Hemorrhagic strokes are more common in older individuals.

Hemorrhagic strokes are more likely to cause brain swelling. (correct)

Hemorrhagic strokes are often caused by underlying conditions like hypertension.

What is the name of the circulatory network at the base of the brain that provides alternative circulation if one of the main vessels is disrupted?

Basilar Artery

Internal Carotid Artery

Cerebral Artery

Circle of Willis (correct)

What is the most common type of stroke, accounting for 70% to 80% of all strokes?

Ischemic Stroke (C) Signup and view all the answers

Which of the following arteries supplies blood to the medulla, pons, cerebellum, midbrain, and caudal part of the diencephalon?

Basilar Artery (D) Signup and view all the answers

Which of the following is a risk factor for stroke?

Diabetes mellitus (C) Signup and view all the answers

Ischemic strokes are caused by which of the following?

Cerebrovascular obstruction (A) Signup and view all the answers

What is the correct terminology for a stroke?

All of the above (D) Signup and view all the answers

What percentage of strokes are classified as small vessel or penetrating artery disease (lacunar stroke)?

25% (D) Signup and view all the answers

Which type of stroke is most often associated with a sudden cerebral hemorrhage?

Hemorrhagic stroke (C) Signup and view all the answers

What does the ischemic penumbra refer to in stroke pathology?

Minimally perfused cells around the core (D) Signup and view all the answers

Which of the following factors is NOT a common predisposing factor for hemorrhagic stroke?

High cholesterol (C) Signup and view all the answers

What is the cerebral blood flow range that defines oligemia?

22–60 mL/100 g/min (C) Signup and view all the answers

Which symptom is commonly associated with the onset of cerebral hemorrhage?

Headache (C) Signup and view all the answers

Which subtype of stroke has an unknown cause and accounts for 30% of cases?

Cryptogenic stroke (A) Signup and view all the answers

What immediate action should be taken if symptoms consistent with a stroke are observed?

Call 9-1-1 (C) Signup and view all the answers

Study Notes

Stroke (Cerebrovascular Accident)

Stroke is an acute neurological deficit caused by a vascular disorder that injures brain tissue.
It's a leading cause of mortality and morbidity in the United States.

Cerebral Circulation

Blood flow to the brain is supplied by two internal carotid arteries (anteriorly) and vertebral arteries (posteriorly).
The internal carotid artery branches into smaller arteries including ophthalmic, posterior communicating, choroidal, anterior cerebral, and middle cerebral arteries.
The two vertebral arteries join to form the basilar artery, supplying the medulla, pons, cerebellum, midbrain, and caudal diencephalon.
The Circle of Willis, an anastomosis of arteries, allows continued circulation if a main vessel is blocked.

Types of Stroke

Two main types: ischemic and hemorrhagic stroke.
Ischemic stroke (70-80% of all strokes): Caused by an interruption of blood flow in a cerebral vessel, usually due to thrombosis or emboli.
Hemorrhagic stroke: Caused by bleeding into brain tissue, often from a ruptured blood vessel. It usually results from hypertension, aneurysms, or head trauma, and has a higher fatality rate than ischemic strokes.

Atherosclerosis Stroke

A type of ischemic stroke where cholesterol plaque buildup blocks blood flow in an artery.

Hemorrhagic Stroke

Spontaneously occurring hemorrhage into the brain tissue results in edema, compression of brain contents, and adjacent blood vessel spasm.
Advancing age and hypertension are common causes. Others include aneurysms, trauma, and drugs.
Symptoms commonly include sudden onset, vomiting, headache, and contralateral hemiplegia (paralysis on opposite side of the body).
The hemorrhage, along with edema, exerts great pressure on brain substance causing a rapid progression to coma and often death.

Risk Factors for Stroke

Age
Sex
Race
Heart disease
Hypertension
High cholesterol levels
Cigarette smoking
Prior stroke
Diabetes mellitus
Excess alcohol use
Sedentary lifestyle

Ischemic Stroke

Caused by cerebrovascular obstruction due to thrombosis or emboli.
Common classification system identifies five subtypes, including large artery atherosclerotic disease (both thrombosis & emboli), small vessel/penetrating artery disease (lacunar stroke), cardiogenic embolism, cryptogenic stroke (undetermined cause), and unusual causes.
Example causes are 20% large artery atherosclerotic disease (both thrombosis and arterial embolus), 25% small vessel or penetrating artery disease (lacunar stroke), 20% cardiogenic embolism and 30% cryptogenic stroke. A further 5% may be due to unusual causes such as migraine.

Ischemic Penumbra

During a stroke, a central core of dead/dying cells is surrounded by an ischemic area of minimally perfused cells (penumbra, or halo).
Cell survival in the penumbra depends on the return of adequate circulation and the volume of toxic products released by neighboring dying cells.
Oligemia (hypo-perfused parenchyma) with cerebral blood flow (CBF) between 22-60 mL/100 g/min is above the ischemic threshold of 22 mL/100 g/min.
The core represents irreversibly injured tissue; diffusion abnormality reflects irreversibly injured tissue; perfusion abnormality represents viable threatened brain tissue surrounded by benign oligemia.

Transient Ischemic Attack (TIA)

Ischemic cerebral neurologic deficits lasting less than 24 hours.
A temporary disturbance in cerebral blood flow.
A TIA is analogous to angina in relation to heart attack.
TIAs are important because they may provide a warning or signal of impending stroke.
Often the risk of stroke after a TIA is maximal immediately after the event.

Signs of Stroke (in Men and Women)

Numbness/weakness (face, arm, leg), especially on one side of the body.
Confusion/trouble speaking or understanding speech.
Trouble seeing in one or both eyes.
Trouble walking, dizziness, or balance problems.
Severe headache with no known cause.

FAST Assessment for Stroke

Face: Ask the person to smile. Does one side of the face droop?
Arms: Ask the person to raise both arms. Does one arm drift downward?
Speech: Ask the person to repeat a simple phrase. Is the speech slurred or strange?
Time: If you see any of these signs, call 9-1-1 right away.

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Description

Test your knowledge on strokes with this comprehensive quiz. Explore different types, causes, and anatomical details related to strokes. Ideal for students studying cardiovascular health or neurology.