CPR Stroke Recognition and Response 1 — Questions and Answers

Question 1: What does the acronym 'FAST' stand for in stroke recognition?

Face droop, Arm weakness, Speech difficulty, Time to call 911 (Correct answer)
Fever, Altered consciousness, Seizure, Transport
Face pain, Asymmetric pupils, Severe headache, Tingling
Fatigue, Arrhythmia, Stroke symptoms, Treatment

Correct answer: Face droop, Arm weakness, Speech difficulty, Time to call 911

FAST stands for Face drooping, Arm weakness, Speech difficulty, and Time to call 911 — the primary stroke warning sign assessment.

FAST is the most widely used stroke recognition tool for the public and first responders: F = Face drooping (ask the person to smile; is one side drooping?), A = Arm weakness (ask the person to raise both arms; does one arm drift downward?), S = Speech difficulty (ask the person to repeat a simple phrase; is the speech slurred or strange?), T = Time to call 911 (if any symptoms are present, note the time of onset and call 911 immediately). The 'time' element is critical because clot-busting medications (tPA) must be given within a specific time window. Some organizations use BE-FAST (Balance, Eyes, Face, Arm, Speech, Time) which adds sudden loss of balance and vision changes.

Question 2: What is the maximum time window for administration of tPA (tissue plasminogen activator) for eligible ischemic stroke patients?

1 hour from symptom onset
3-4.5 hours from last known well time (Correct answer)
6 hours from symptom onset
12 hours from symptom onset

Correct answer: 3-4.5 hours from last known well time

tPA can be administered within 3-4.5 hours of last known well time in eligible ischemic stroke patients to dissolve the clot.

Intravenous alteplase (tPA) is the primary thrombolytic therapy for acute ischemic stroke. The original FDA-approved window is 3 hours from last known well time, but guidelines (AHA/ASA) extend this to 4.5 hours for patients who meet eligibility criteria (younger than 80, not taking oral anticoagulants, NIHSS ≤25, no prior stroke and diabetes). Every minute of stroke equals approximately 1.9 million neurons lost. Mechanical thrombectomy (endovascular clot removal) extends treatment to 6-24 hours for select patients with large vessel occlusion. The key principle is that every minute of delay decreases the chance of meaningful recovery, making rapid recognition, activation, and transport critical.

Question 3: A patient suddenly develops severe 'thunderclap' headache described as 'the worst headache of my life.' What type of stroke should be suspected?

Ischemic stroke from large vessel occlusion
Subarachnoid hemorrhage (bleeding around the brain) (Correct answer)
Transient ischemic attack (TIA)
Hypertensive encephalopathy

Correct answer: Subarachnoid hemorrhage (bleeding around the brain)

A sudden, severe 'thunderclap' headache is the classic presentation of subarachnoid hemorrhage (SAH), a life-threatening emergency.

Subarachnoid hemorrhage (SAH), typically caused by a ruptured cerebral aneurysm, classically presents with a sudden-onset, severe headache described as the 'worst headache of my life' or a 'thunderclap' headache. This headache reaches maximum intensity within seconds to minutes. Other features may include nausea, vomiting, neck stiffness, photophobia, and brief loss of consciousness. SAH represents approximately 5% of strokes and carries a high mortality rate (25-50%), with many patients dying before reaching the hospital. Any patient presenting with this type of headache requires urgent CT scan and neurosurgical evaluation. Treatment may include surgical clipping or endovascular coiling of the aneurysm.

Question 4: Which of the following is NOT a typical warning sign of stroke?

Sudden numbness or weakness of the face, arm, or leg, especially on one side
Sudden confusion, trouble speaking, or understanding speech
Gradual onset of bilateral leg weakness over several days (Correct answer)
Sudden trouble seeing in one or both eyes

Correct answer: Gradual onset of bilateral leg weakness over several days

Stroke symptoms are typically sudden in onset. Gradual bilateral symptoms over days are more characteristic of other conditions (e.g., spinal cord disease, Guillain-Barré).

Classic stroke warning signs include sudden onset of: unilateral face, arm, or leg numbness/weakness; confusion or trouble speaking/understanding; vision problems in one or both eyes; severe headache with no known cause; and trouble walking, dizziness, or loss of balance/coordination. The sudden onset is a distinguishing feature—symptoms that develop gradually over hours to days are more suggestive of other conditions. Bilateral symptoms (both sides of the body equally) are less typical of stroke (which usually affects one side due to unilateral vessel occlusion) and may suggest a spinal cord problem, toxic-metabolic condition, or central process. Always take sudden neurological symptoms seriously until proven otherwise.

Question 5: What is the difference between an ischemic stroke and a hemorrhagic stroke?

Ischemic stroke involves bleeding in the brain; hemorrhagic stroke involves a clot
Ischemic stroke is caused by a clot blocking blood flow; hemorrhagic stroke is caused by a ruptured blood vessel bleeding into or around the brain (Correct answer)
They are different names for the same condition
Ischemic stroke only affects the brainstem; hemorrhagic stroke only affects the cortex

Correct answer: Ischemic stroke is caused by a clot blocking blood flow; hemorrhagic stroke is caused by a ruptured blood vessel bleeding into or around the brain

Ischemic stroke (87% of strokes) is caused by arterial occlusion; hemorrhagic stroke is caused by vessel rupture causing bleeding into brain tissue or subarachnoid space.

Strokes are classified into two major types: Ischemic strokes (approximately 87% of all strokes) occur when a blood clot blocks or significantly narrows an artery supplying the brain, preventing oxygen delivery to brain tissue. Types include thrombotic (in-situ clot formation) and embolic (clot from elsewhere, often the heart). Hemorrhagic strokes (approximately 13%) occur when a blood vessel ruptures and bleeds directly into brain tissue (intracerebral hemorrhage, ICH) or into the subarachnoid space (subarachnoid hemorrhage, SAH). This distinction is critical because treatment differs: tPA (thrombolytics) are used for ischemic stroke but are absolutely contraindicated in hemorrhagic stroke as they would worsen bleeding.

Question 6: What is a transient ischemic attack (TIA), and why is it clinically important?

A mild stroke with permanent but minor deficits
A brief episode of neurological dysfunction caused by temporary brain ischemia that resolves completely, serving as a warning sign of impending stroke (Correct answer)
A type of heart attack that mimics stroke symptoms
A stroke that only affects the eye

Correct answer: A brief episode of neurological dysfunction caused by temporary brain ischemia that resolves completely, serving as a warning sign of impending stroke

A TIA causes transient stroke-like symptoms that fully resolve, but carries a high short-term risk of complete stroke (up to 10% within 48 hours).

A transient ischemic attack (TIA) produces stroke-like symptoms (unilateral weakness, speech difficulty, vision changes, etc.) caused by temporary focal brain ischemia that resolves completely—by definition, within 24 hours, though most TIAs resolve within 1 hour. The clinical importance of TIA cannot be overstated: the risk of complete stroke is approximately 10-15% within 90 days, with the highest risk in the first 48 hours. The ABCD2 score (age, blood pressure, clinical features, duration, diabetes) helps stratify TIA risk. Patients with TIA require urgent evaluation including brain imaging, vascular imaging, cardiac monitoring, and initiation of antiplatelet/anticoagulant therapy to prevent subsequent stroke.

Question 7: What is the recommended first response action when stroke is suspected in a community setting?

Drive the patient to the hospital immediately
Give the patient aspirin and water
Call 911 immediately and note the time symptoms started (Correct answer)
Wait 30 minutes to see if symptoms resolve

Correct answer: Call 911 immediately and note the time symptoms started

Call 911 immediately and note the exact time symptoms started—this information is critical for determining tPA eligibility at the hospital.

When stroke is suspected, calling 911 immediately is the correct first action for several reasons: (1) EMS providers can begin assessment and notify the receiving hospital, activating the stroke team before arrival ('stroke code'), (2) EMS transport is generally faster than self-transport and ensures the patient is monitored during transport, (3) EMS can document the exact time of symptom onset (or last known well time), which is critical for tPA eligibility determination, (4) EMS providers can begin IV access and supplemental oxygen as needed during transport. Driving the patient privately risks delay (traffic, parking) and arrives without pre-notification, costing precious minutes. Aspirin should not be given until hemorrhagic stroke is excluded by CT scan.

Question 8: Which scale is commonly used by EMS providers to screen for stroke in the field?

Glasgow Coma Scale (GCS)
Cincinnati Prehospital Stroke Scale (CPSS) (Correct answer)
NIHSS (National Institutes of Health Stroke Scale)
ABCD2 Score

Correct answer: Cincinnati Prehospital Stroke Scale (CPSS)

The Cincinnati Prehospital Stroke Scale (CPSS) is a 3-item tool (facial droop, arm drift, speech) validated for prehospital stroke screening.

The Cincinnati Prehospital Stroke Scale (CPSS) is a validated 3-item stroke screening tool used by EMS providers in the field: (1) Facial droop: ask the patient to smile—asymmetric droop is abnormal, (2) Arm drift: ask the patient to raise both arms with eyes closed—unilateral arm drift or weakness is abnormal, (3) Speech: ask the patient to repeat 'You can't teach an old dog new tricks'—slurred, wrong words, or inability to speak is abnormal. Presence of any one abnormal finding has 72% sensitivity and 90% specificity for acute stroke. Other prehospital tools include the Los Angeles Prehospital Stroke Screen (LAPSS) and the Melbourne Ambulance Stroke Screen (MASS).

Question 9: What does 'penumbra' refer to in the context of ischemic stroke management?

The area of dead brain tissue at the center of the infarct
The zone of ischemic but potentially salvageable brain tissue surrounding the core infarct (Correct answer)
Bleeding around the stroke area
The shadow of the clot seen on CT scan

Correct answer: The zone of ischemic but potentially salvageable brain tissue surrounding the core infarct

The ischemic penumbra is the at-risk but potentially recoverable brain tissue surrounding the dead core infarct—the target for acute stroke treatments.

In ischemic stroke, the affected brain territory has two zones: the ischemic core (where blood flow is severely reduced, cells die within minutes, and tissue is irreversibly injured) and the ischemic penumbra (surrounding area where blood flow is reduced but not absent, cells are metabolically impaired but still alive and potentially salvageable). The penumbra is the target of all acute stroke therapies—thrombolysis, thrombectomy, and neuroprotection. Without treatment, penumbral tissue progressively converts to infarct core over hours. Advanced neuroimaging (MRI diffusion/perfusion or CT perfusion) can visualize the core and penumbra, helping select patients for extended-window reperfusion therapies.

Question 10: What type of stroke involves a blood vessel rupturing within the brain tissue itself (not in the subarachnoid space)?

Subarachnoid hemorrhage (SAH)
Intracerebral hemorrhage (ICH) (Correct answer)
Embolic ischemic stroke
Lacunar infarct

Correct answer: Intracerebral hemorrhage (ICH)

Intracerebral hemorrhage (ICH) involves bleeding directly into brain parenchyma, most commonly due to hypertension.

Intracerebral hemorrhage (ICH) occurs when a blood vessel ruptures and bleeds directly into the brain parenchyma (brain tissue), forming a hematoma. It accounts for approximately 10% of all strokes. The most common cause is hypertension, which damages small penetrating arteries (particularly those supplying the basal ganglia, thalamus, pons, and cerebellum). Other causes include amyloid angiopathy, coagulopathies, vascular malformations, and anticoagulant medications. ICH typically presents with sudden onset neurological deficits, often with headache and rapid deterioration. CT scan without contrast is the first diagnostic step. Treatment focuses on blood pressure control, reversal of coagulopathy, and neurosurgical consultation. Thrombolytics are absolutely contraindicated.

Question 11: What is the 'door-to-needle' time target for tPA administration in eligible ischemic stroke patients?

Within 30 minutes of hospital arrival
Within 60 minutes of hospital arrival (Correct answer)
Within 90 minutes of hospital arrival
Within 120 minutes of hospital arrival

Correct answer: Within 60 minutes of hospital arrival

The AHA/ASA recommends tPA administration within 60 minutes of hospital arrival (door-to-needle time ≤60 minutes).

The 'door-to-needle' (DTN) time is a key quality metric for stroke centers—it measures the time from patient arrival to tPA administration. The AHA/ASA target is ≤60 minutes, with the benchmark for top-performing centers being ≤45 minutes. Achieving rapid DTN times requires pre-notification from EMS, rapid triage to the CT scanner, immediate availability of the stroke team, and streamlined laboratory processing. Studies consistently show that faster DTN times are associated with better functional outcomes and lower mortality. Similarly, 'door-to-groin' time (for mechanical thrombectomy) should be ≤90 minutes. Many comprehensive stroke centers have implemented protocols achieving median DTN times under 45 minutes.

Question 12: What are the warning signs of stroke in the posterior circulation (vertebrobasilar territory)?

Facial droop, arm weakness, speech difficulty
Dizziness, sudden loss of balance, double vision, severe headache, difficulty swallowing (Correct answer)
Chest pain radiating to left arm, jaw pain, sweating
Confusion, fever, high blood pressure

Correct answer: Dizziness, sudden loss of balance, double vision, severe headache, difficulty swallowing

Posterior circulation strokes affect the brainstem and cerebellum, causing dizziness, balance problems, diplopia, dysphagia, and occipital headache.

Posterior circulation strokes affect the vertebrobasilar territory, which supplies the brainstem, cerebellum, thalamus, and occipital lobes. Symptoms may include: sudden severe dizziness or vertigo, sudden loss of balance or coordination (ataxia), double vision (diplopia), difficulty swallowing (dysphagia), sudden facial numbness, crossed deficits (ipsilateral face with contralateral body), sudden loss of vision in both eyes or visual field defects, and sudden occipital headache. Posterior circulation strokes are often more difficult to diagnose because symptoms like dizziness are common and may be attributed to other causes. CT scan is less sensitive for posterior fossa strokes—MRI with diffusion-weighted imaging is preferred.

Question 13: Why should aspirin NOT be given to a stroke patient before hospital evaluation?

Aspirin causes allergic reactions in most patients
Aspirin is only effective for heart attacks, not strokes
Aspirin could worsen hemorrhagic stroke by interfering with clotting (Correct answer)
Aspirin interacts with tPA and cannot be given together

Correct answer: Aspirin could worsen hemorrhagic stroke by interfering with clotting

Aspirin is contraindicated in hemorrhagic stroke because it impairs platelet function and worsens intracranial bleeding; CT scan is needed first to exclude hemorrhage.

While aspirin is an effective treatment for ischemic stroke (started within 24-48 hours to prevent recurrence), it cannot be administered until hemorrhagic stroke has been excluded by CT scan. Aspirin inhibits platelet aggregation—in hemorrhagic stroke (either ICH or SAH), antiplatelet therapy would impair the body's ability to stop the bleeding and could significantly worsen intracranial hemorrhage expansion. Since ischemic and hemorrhagic strokes cannot be reliably distinguished clinically (both present with sudden neurological deficits), CT imaging is mandatory before any antithrombotic treatment. In the field, the priority is rapid transport to a stroke center; EMS should not administer aspirin for suspected stroke.

Question 14: What is 'mechanical thrombectomy' in the context of stroke treatment?

Manual CPR performed on stroke patients
Endovascular removal of a blood clot from a large cerebral artery using specialized catheter-based devices (Correct answer)
A type of brain surgery to remove the stroke-damaged area
Blood pressure medication given intravenously to prevent clot extension

Correct answer: Endovascular removal of a blood clot from a large cerebral artery using specialized catheter-based devices

Mechanical thrombectomy uses catheters and stent retrievers inserted through the femoral artery to physically remove clots from large intracranial vessels.

Mechanical thrombectomy (endovascular therapy/EVT) is a procedure in which a neurointerventionalist inserts a catheter through the femoral artery, navigates it to the intracranial vessel containing the clot, and uses aspiration catheters, stent retrievers, or both to mechanically remove the thrombus. Randomized trials (MR CLEAN, SWIFT PRIME, ESCAPE, etc.) demonstrated dramatic benefits in large vessel occlusion (LVO) strokes—approximately one in every 2.6 patients treated benefited significantly. Eligibility extends to 6-24 hours from onset for selected patients (DAWN and DEFUSE 3 trials). The procedure requires comprehensive stroke centers with 24/7 neurointerventional capability.

Question 15: What neurological assessment scale do healthcare providers use to quantify stroke severity and deficits?

Glasgow Coma Scale (GCS)
National Institutes of Health Stroke Scale (NIHSS) (Correct answer)
Rankin Scale
ABCD2 Score

Correct answer: National Institutes of Health Stroke Scale (NIHSS)

The NIHSS is an 11-item structured neurological examination that quantifies stroke deficits from 0 (normal) to 42 (most severe), guiding treatment decisions.

The National Institutes of Health Stroke Scale (NIHSS) is a 15-item (scored across 11 domains) standardized neurological assessment tool that quantifies stroke severity. Domains include: level of consciousness, eye movement, visual fields, facial palsy, arm and leg motor function, limb ataxia, sensory function, language, dysarthria, and neglect/inattention. Scores range from 0 (no deficit) to 42 (most severe). The NIHSS guides treatment decisions: patients with NIHSS ≥6 are typically considered for mechanical thrombectomy evaluation; tPA is typically considered for NIHSS ≥4. Serial NIHSS measurements track improvement or deterioration. NIHSS certification is required for clinicians at certified stroke centers.

Question 16: Which of the following is a contraindication to tPA therapy in ischemic stroke?

Age over 18 years
Blood pressure above 185/110 mmHg (uncontrolled at time of treatment) (Correct answer)
Symptom onset within 3 hours
No evidence of hemorrhage on CT scan

Correct answer: Blood pressure above 185/110 mmHg (uncontrolled at time of treatment)

Blood pressure must be reduced to ≤185/110 mmHg before tPA administration to reduce hemorrhagic transformation risk.

Absolute contraindications to tPA in ischemic stroke include: any intracranial hemorrhage, BP >185/110 mmHg that cannot be lowered safely, current use of direct thrombin inhibitors or factor Xa inhibitors, evidence of active internal bleeding, blood glucose <50 mg/dL, and prior intracranial surgery/head trauma within 3 months. BP >185/110 is a contraindication because hypertension significantly increases the risk of symptomatic hemorrhagic transformation after tPA. However, unlike some contraindications, this one can be addressed—labetalol or nicardipine can be used to reduce blood pressure to the required level before giving tPA. The benefit-risk ratio must be carefully considered for each patient.

Question 17: What does the 'BE-FAST' acronym add to the original 'FAST' stroke recognition tool?

Blood pressure and Eye movement testing
Balance problems and sudden Eye/vision changes (Correct answer)
Breathing difficulty and Extremity weakness
Brain imaging and Emergency treatment

Correct answer: Balance problems and sudden Eye/vision changes

BE-FAST adds B for sudden Balance loss and E for sudden Eye/vision problems to the original FAST, helping recognize posterior circulation strokes.

BE-FAST expands the original FAST acronym by adding two additional warning signs at the beginning: B = sudden loss of Balance, coordination, or trouble walking, and E = sudden vision changes or loss in one or both Eyes. These additions were incorporated to capture posterior circulation strokes (vertebrobasilar territory), which more commonly present with balance and vision symptoms rather than the classic FAST symptoms. Studies showed that FAST missed approximately 14-17% of posterior circulation strokes. BE-FAST improves stroke recognition sensitivity from approximately 85% (FAST) to approximately 95% (BE-FAST). The full acronym: Balance, Eyes, Face drooping, Arm weakness, Speech difficulty, Time to call 911.

Question 18: What initial first aid action should a lay rescuer take for a person experiencing a suspected stroke?

Give water and have the person lie down with head elevated 30 degrees
Keep the person calm, note the time symptoms started, call 911, do not give food or drink (Correct answer)
Perform CPR if the person is unresponsive
Give aspirin immediately and monitor the person

Correct answer: Keep the person calm, note the time symptoms started, call 911, do not give food or drink

Keep the person calm, note symptom onset time precisely, call 911, and don't give food or drink due to potential swallowing problems.

For a conscious person with suspected stroke, lay rescuers should: (1) Call 911 immediately—don't drive the person to the hospital, (2) Note the time when symptoms first appeared or the last time the person was known to be normal (last known well time)—this is critical for treatment decisions, (3) Keep the person calm and as still as possible, (4) Do NOT give food or water—stroke can impair swallowing (dysphagia), increasing aspiration risk, (5) Do NOT give aspirin without consulting medical direction, (6) If the person is unresponsive but breathing, place in recovery position, (7) If the person stops breathing, begin CPR. Early EMS activation with symptom time documentation dramatically improves outcomes.

Question 19: How does stroke differ from cardiac arrest, and how does this affect the initial emergency response?

Stroke and cardiac arrest require identical responses
In stroke, the heart is still beating and CPR is not indicated; the priority is rapid transport to a stroke center for time-sensitive interventions (Correct answer)
In stroke, the heart stops first; CPR should be started immediately
Stroke requires defibrillation, while cardiac arrest requires thrombolytics

Correct answer: In stroke, the heart is still beating and CPR is not indicated; the priority is rapid transport to a stroke center for time-sensitive interventions

Stroke patients typically have a pulse and are often conscious; the priority is rapid transport to a certified stroke center, not CPR.

Stroke and cardiac arrest are distinct emergencies requiring different initial responses. In stroke, the heart continues to beat and the patient often remains conscious (though possibly confused or unable to communicate). The primary intervention is rapid transport to a certified stroke center where time-sensitive treatments (tPA, thrombectomy) can be administered. CPR is not indicated unless the patient also develops cardiac arrest. In contrast, cardiac arrest requires immediate CPR and defibrillation as the priority. Both are time-critical emergencies: 'time is brain' for stroke (every minute of stroke delays tPA = 1.9 million neurons lost), and 'time is muscle and brain' for cardiac arrest (every minute without CPR decreases survival 7-10%).

Question 20: Which of the following statements about stroke and age is accurate?

Stroke only occurs in elderly patients over 65
While stroke risk increases with age, strokes can occur at any age including in young adults, children, and newborns (Correct answer)
Children cannot have strokes because their blood vessels are too flexible
Strokes in patients under 40 are always caused by drug use

Correct answer: While stroke risk increases with age, strokes can occur at any age including in young adults, children, and newborns

Stroke can affect people of all ages; while risk increases with age, young adults and children can have strokes from various causes.

While stroke risk increases with age (approximately doubling with each decade after 55), strokes can and do occur at any age. In young adults (18-45), causes include cardioembolism (patent foramen ovale, atrial fibrillation, valvular disease), cervical artery dissection, hypercoagulable states, drug use (cocaine, amphetamines), and cryptogenic causes. In children, causes include sickle cell disease, congenital heart disease, and genetic coagulopathies. In neonates, perinatal stroke can occur during delivery. Pediatric and young adult strokes are increasingly recognized, but diagnosis may be delayed because stroke is not initially suspected in young patients—increasing awareness of all-age stroke recognition is critical.

Question 21: What is 'hemorrhagic transformation' in the context of ischemic stroke?

When ischemic stroke converts to cardiac arrest
Bleeding into an area of ischemic brain tissue, a potential complication of stroke that can be worsened by tPA (Correct answer)
The process of reabsorbing old blood clots in the brain
When a hemorrhagic stroke improves without treatment

Correct answer: Bleeding into an area of ischemic brain tissue, a potential complication of stroke that can be worsened by tPA

Hemorrhagic transformation is bleeding into ischemic brain tissue, a feared complication of reperfusion that can cause neurological deterioration, especially post-tPA.

Hemorrhagic transformation (HT) is a complication in which blood extravasates into ischemic brain tissue. It can occur spontaneously in large ischemic strokes (due to reperfusion through damaged, fragile vessels) or be precipitated by thrombolytic therapy (tPA). HT ranges from petechial hemorrhage (small blood spots, often asymptomatic) to parenchymal hematoma (large, space-occupying hemorrhage causing clinical deterioration). Symptomatic intracranial hemorrhage (sICH) after tPA occurs in approximately 6% of treated patients but is the major risk limiting tPA use. Risk factors for HT include large infarct size, high blood glucose, advanced age, and high blood pressure. Management includes stopping tPA if being infused and reversing coagulopathy.

Question 22: In the context of stroke care, what does the term 'last known well' (LKW) mean?

The time the patient was last seen by a physician
The last time the patient was observed or confirmed to be without stroke symptoms (Correct answer)
The time the ambulance arrived at the scene
The time the patient's symptoms were at their worst

Correct answer: The last time the patient was observed or confirmed to be without stroke symptoms

Last known well is the precise time when the patient was last confirmed to be without stroke symptoms, used as the baseline for treatment window calculations.

Last known well (LKW), also called 'last known normal,' is the most recent time at which the patient was verified to be without any signs or symptoms of stroke. This is used as time zero for calculating treatment windows when the exact onset time is unknown. For example, if a patient woke up with stroke symptoms, the LKW is the time they went to sleep (not when they woke up). This 'wake-up stroke' scenario requires different evaluation protocols, including advanced imaging (MRI DWI/FLAIR mismatch) to determine if the stroke occurred within the treatment window. Accurate LKW documentation by EMS and emergency personnel is one of the most important pieces of information in acute stroke management.

Question 23: What is the role of CT scan in the emergency evaluation of stroke?

It definitively identifies all ischemic strokes immediately
It primarily rules out hemorrhagic stroke and identifies other stroke mimics, guiding treatment decisions (Correct answer)
It measures the exact size of the stroke in real time
It guides direct arterial thrombus removal

Correct answer: It primarily rules out hemorrhagic stroke and identifies other stroke mimics, guiding treatment decisions

Non-contrast CT is the first-line imaging test—it quickly identifies intracranial hemorrhage (contraindicating tPA) and stroke mimics, though early ischemic changes may not be visible.

Non-contrast CT (NCCT) of the brain is the first-line imaging study in suspected acute stroke for several reasons: (1) It is fast (typically completed in minutes), widely available 24/7, and doesn't require special preparation, (2) It reliably identifies intracranial hemorrhage (appearing as hyperdense/bright areas), which is the primary purpose—if hemorrhage is found, tPA is contraindicated, (3) It can identify stroke mimics (tumors, abscesses, subdural hematoma), (4) However, early ischemic changes are often invisible on NCCT in the first 3-6 hours. For this reason, CT angiography (CTA) and CT perfusion (CTP) or MRI are added to identify large vessel occlusions and penumbra for thrombectomy planning.

Question 24: Which condition is known as a 'stroke mimic' and can be confused with stroke symptoms?

Hypertension
Todd's paralysis (post-ictal weakness after a seizure) (Correct answer)
Atrial fibrillation
Myocardial infarction

Correct answer: Todd's paralysis (post-ictal weakness after a seizure)

Todd's paralysis is focal post-seizure weakness that can perfectly mimic stroke symptoms, making it one of the most common stroke mimics.

Stroke mimics are conditions that can present with sudden neurological deficits that resemble stroke. Todd's paralysis (post-ictal paralysis) is one of the most common—following a seizure (which may not have been witnessed), focal weakness can persist for minutes to hours, exactly mimicking contralateral stroke. Other common stroke mimics include: hypoglycemia (can cause focal deficits—check blood glucose in all suspected stroke patients), complicated migraine (hemiplegic migraine), brain tumor, encephalitis, hypertensive encephalopathy, conversion disorder, and peripheral vertigo. Since stroke mimics account for up to 30% of suspected stroke presentations, imaging (CT/MRI) is essential. Crucially, a treatment decision should not be delayed solely due to concern about stroke mimics—the risks of treating a mimic with tPA are generally much lower than missing a true stroke.

Question 25: What stroke risk factor is most modifiable and responsible for the highest population-attributable risk?

Age
Hypertension (Correct answer)
Genetics
Gender

Correct answer: Hypertension

Hypertension is the single most important modifiable stroke risk factor, responsible for approximately 35-40% of population-attributable risk.

Hypertension is the most important modifiable risk factor for both ischemic and hemorrhagic stroke, with a population-attributable risk of approximately 35-40%. Both systolic and diastolic hypertension increase stroke risk, and the relationship is graded—higher blood pressure = higher risk. The risk persists even at blood pressure levels above 115/75 mmHg. Importantly, antihypertensive treatment reduces stroke risk by approximately 35-40%. Other major modifiable risk factors include atrial fibrillation, diabetes, smoking, hyperlipidemia, physical inactivity, obesity, and excessive alcohol consumption. Non-modifiable risk factors include age, gender (male), race (Black Americans have 2x the stroke risk), and family history.

Question 26: In the response to stroke, what does 'time is brain' specifically mean quantitatively?

Patients have only 60 minutes before brain cells permanently die
With each minute of untreated stroke, approximately 1.9 million neurons, 13.8 billion synapses, and 12 km of myelinated fibers are lost (Correct answer)
The brain can only tolerate 5 minutes of ischemia before total death
Stroke symptoms double in severity every hour

Correct answer: With each minute of untreated stroke, approximately 1.9 million neurons, 13.8 billion synapses, and 12 km of myelinated fibers are lost

Every minute of ischemic stroke causes the death of approximately 1.9 million neurons, quantifying the urgency of rapid reperfusion therapy.

The phrase 'time is brain' was made quantitatively meaningful by Saver (2006), who calculated that during acute ischemic stroke with large vessel occlusion, every minute of untreated stroke results in the death of approximately 1.9 million neurons, 13.8 billion synapses, and 12 km (7.5 miles) of myelinated nerve fibers. Compared to normal aging, the ischemic brain ages approximately 3.6 years per hour. Over the typical course of an untreated major stroke, the total neuron loss is equivalent to approximately 3.5 years of normal aging. This quantification powerfully illustrates why every minute from symptom onset to reperfusion matters—reducing time to treatment by even 15-20 minutes translates to thousands of neurons saved and significantly better functional outcomes.

Question 27: What is the appropriate response if a person with suspected stroke becomes unresponsive and stops breathing?

Continue monitoring and wait for EMS
Place in recovery position and wait
Begin CPR and call 911 immediately (Correct answer)
Administer aspirin and recheck in 5 minutes

Correct answer: Begin CPR and call 911 immediately

If a stroke patient becomes unresponsive and stops breathing, start CPR immediately—stroke can precipitate cardiac arrest, and CPR and 911 are the priorities.

Stroke can occasionally precipitate cardiac arrest through several mechanisms: massive brain hemorrhage causing herniation, brain stem stroke disrupting cardiac/respiratory centers, or neurogenic pulmonary edema leading to respiratory failure. If a stroke patient becomes unresponsive and is not breathing normally, the response is identical to any cardiac arrest: call 911 if not done, begin CPR starting with chest compressions, and use an AED if available. The underlying stroke does not change the cardiac arrest management—high-quality CPR and early defibrillation (if shockable rhythm) remain the priorities. After ROSC, post-arrest care should include consideration of the stroke as the precipitating cause and appropriate imaging and treatment.

Question 28: What is the difference between hemorrhagic stroke and hypertensive encephalopathy?

They are the same condition
Hemorrhagic stroke involves vessel rupture with bleeding into brain tissue; hypertensive encephalopathy involves diffuse cerebral edema from severely elevated BP without focal bleeding, typically reversible with BP reduction (Correct answer)
Hypertensive encephalopathy causes more severe deficits
Hemorrhagic stroke is always fatal; hypertensive encephalopathy never is

Correct answer: Hemorrhagic stroke involves vessel rupture with bleeding into brain tissue; hypertensive encephalopathy involves diffuse cerebral edema from severely elevated BP without focal bleeding, typically reversible with BP reduction

Hypertensive encephalopathy causes diffuse brain dysfunction from severely elevated BP and is typically reversible; hemorrhagic stroke involves actual bleeding and structural damage.

Hypertensive encephalopathy is a syndrome of acute brain dysfunction caused by severe hypertension (typically BP >180/120 mmHg) resulting in breakthrough of cerebrovascular autoregulation, leading to cerebral edema and dysfunction. Unlike hemorrhagic stroke, there is no actual vessel rupture—the dysfunction is from vasogenic edema that is typically reversible with appropriate blood pressure reduction. Clinically it presents with headache, confusion, visual disturbances, and seizures—without the focal deficits typical of stroke. CT shows diffuse white matter changes (PRES—posterior reversible encephalopathy syndrome). Prompt blood pressure reduction (carefully, not too rapidly) leads to clinical improvement. Distinguishing it from hemorrhagic stroke requires brain imaging.

Question 29: What is the significance of 'atrial fibrillation' as a stroke risk factor?

AF only causes strokes in elderly patients
AF causes irregular atrial contractions that allow blood to stagnate and form clots in the left atrial appendage, which can embolize to the brain causing cardioembolic stroke (Correct answer)
AF is less dangerous than hypertension for stroke risk
AF increases stroke risk only when it causes fast heart rate

Correct answer: AF causes irregular atrial contractions that allow blood to stagnate and form clots in the left atrial appendage, which can embolize to the brain causing cardioembolic stroke

AF promotes left atrial appendage thrombus formation due to stagnant blood flow; these clots can embolize to cerebral vessels causing cardioembolic stroke.

Atrial fibrillation (AF) is the most common cardiac arrhythmia and a major independent risk factor for stroke, increasing stroke risk 4-5 times. In AF, disorganized atrial electrical activity prevents coordinated atrial contractions, causing blood to stagnate—particularly in the left atrial appendage (LAA), a small pouch in the left atrium. Stagnant blood is prone to thrombus formation. AF-related thrombi can embolize through the left ventricle and aorta to cerebral vessels, causing large cardioembolic strokes that are often severe. Anticoagulation therapy (warfarin, direct oral anticoagulants) dramatically reduces this risk (60-70% stroke reduction). The CHA₂DS₂-VASc score guides anticoagulation decisions in AF patients.

Question 30: What is the role of CT angiography (CTA) in acute stroke evaluation?

CTA is used instead of non-contrast CT to look for bleeding
CTA visualizes the cerebral arteries to identify large vessel occlusions (LVO) amenable to mechanical thrombectomy and assess arterial stenosis (Correct answer)
CTA measures brain tissue viability
CTA is only used for hemorrhagic stroke evaluation

Correct answer: CTA visualizes the cerebral arteries to identify large vessel occlusions (LVO) amenable to mechanical thrombectomy and assess arterial stenosis

CTA identifies large vessel occlusions and vascular anatomy to determine whether mechanical thrombectomy is feasible and guide endovascular planning.

CT angiography (CTA) of the head and neck is a critical component of acute stroke evaluation in patients who may be candidates for mechanical thrombectomy. CTA uses intravenous contrast to visualize the cervical and intracranial arteries, identifying: large vessel occlusions (LVO—blockages of the ICA, M1/M2 MCA, basilar artery, etc.) that may be amenable to endovascular thrombectomy, arterial stenosis or dissection, circle of Willis anatomy for surgical planning, and concurrent aneurysms. In most stroke centers, CTA is performed simultaneously with non-contrast CT ('one-stop' stroke CT protocol). LVO identification is critical because thrombectomy for LVO dramatically improves outcomes—patients with LVO who receive thrombectomy achieve functional independence at rates 2-3x higher than those receiving only tPA.

Question 31: What does 'NIHSS score' of 0 indicate in a stroke patient?

The most severe possible deficit
No neurological deficit detected on examination (Correct answer)
The patient is in a coma
The patient requires immediate surgery

Correct answer: No neurological deficit detected on examination

NIHSS 0 indicates a normal neurological examination with no detectable deficits; scores increase with greater deficit severity up to a maximum of 42.

The National Institutes of Health Stroke Scale (NIHSS) ranges from 0 (no deficit) to 42 (maximum possible deficit). A score of 0 means the patient passed all 15 examination items with normal responses. Score interpretation: 0=no stroke, 1-4=minor stroke, 5-15=moderate stroke, 16-20=moderately severe stroke, 21-42=severe stroke. The NIHSS is important not just for severity but for treatment decisions: patients with NIHSS <4 were traditionally excluded from tPA trials (though emerging evidence supports treating even minor strokes causing disability), and patients with high NIHSS scores may be prioritized for thrombectomy evaluation. Serial NIHSS assessments track neurological improvement or deterioration.

Question 32: How does collateral circulation affect stroke severity and treatment outcomes?

Collateral circulation has no effect on stroke outcomes
Robust collateral blood supply maintains partial perfusion to ischemic brain tissue, reducing penumbra progression and extending the time window during which reperfusion therapy can be effective (Correct answer)
Collateral circulation always prevents stroke entirely
Better collaterals mean surgery is required instead of tPA

Correct answer: Robust collateral blood supply maintains partial perfusion to ischemic brain tissue, reducing penumbra progression and extending the time window during which reperfusion therapy can be effective

Good collateral circulation slows ischemic penumbra progression, allowing more time for effective reperfusion therapy and predicting better treatment response.

Cerebral collateral circulation—alternative vascular pathways (leptomeningeal anastomoses, circle of Willis variants, external-to-internal carotid anastomoses) that can supply blood to regions with occluded primary vessels—is a major determinant of stroke severity and treatment response. Patients with robust collaterals have: smaller ischemic cores at presentation, more salvageable penumbra, slower progression of infarct growth, better response to reperfusion therapy (tPA and thrombectomy), and better clinical outcomes. CT perfusion and angiographic collateral grading are used to select patients for extended-window thrombectomy (6-24 hours). The presence of good collaterals 'buys time' by maintaining partial perfusion to at-risk tissue. Collateral status varies significantly between individuals and explains why two patients with identical arterial occlusions can have very different stroke severities.

Question 33: What is a 'drip and ship' versus 'mothership' model in stroke systems of care?

Names for different types of ambulances used in stroke transport
'Drip and ship' means giving tPA at a primary stroke center then transferring for thrombectomy; 'mothership' means bypassing local hospitals and going directly to a comprehensive stroke center (Correct answer)
'Drip and ship' is for hemorrhagic stroke; 'mothership' is for ischemic stroke
These terms describe clot-busting medication administration protocols

Correct answer: 'Drip and ship' means giving tPA at a primary stroke center then transferring for thrombectomy; 'mothership' means bypassing local hospitals and going directly to a comprehensive stroke center

'Drip and ship' administers tPA at the nearest center then transfers for thrombectomy; 'mothership' bypasses to a comprehensive center with both tPA and thrombectomy capability.

For patients with large vessel occlusion stroke, two transport strategies are debated: (1) 'Drip and ship'—take the patient to the nearest primary stroke center (PSC) capable of giving tPA, administer tPA, then transfer to a comprehensive stroke center (CSC) for thrombectomy if indicated. This minimizes time to tPA but adds time to thrombectomy. (2) 'Mothership'—bypass the PSC and go directly to a CSC equipped for both tPA and thrombectomy, accepting a longer transport time in exchange for a one-stop comprehensive treatment approach. Research (RACECAT, DIRECT-SAFE trials) has produced mixed results, and optimal strategy depends heavily on transport times and local system capabilities. EMS protocols increasingly use LVO screening tools (RACE, LAMS, FAST-ED scales) to identify potential LVO patients who might benefit from direct CSC transport.

Question 34: What is the initial assessment priority for a conscious patient reporting 'the worst headache of my life'?

Reassure the patient that tension headaches are common and prescribe pain medication
Perform an immediate head CT without contrast to rule out subarachnoid hemorrhage before any other diagnosis is entertained (Correct answer)
Take a detailed 30-minute headache history before imaging
Prescribe triptans assuming migraine diagnosis

Correct answer: Perform an immediate head CT without contrast to rule out subarachnoid hemorrhage before any other diagnosis is entertained

'Worst headache of my life' is a red flag requiring immediate CT to exclude subarachnoid hemorrhage before any other management.

The phrase 'worst headache of my life' or 'thunderclap headache' (reaching maximum intensity within 60 seconds of onset) is a neurological emergency requiring urgent evaluation for subarachnoid hemorrhage (SAH). The immediate priority is non-contrast CT of the brain, which detects approximately 95-98% of SAH in the first 12 hours. If CT is negative but clinical suspicion remains high, lumbar puncture (LP) is performed to look for xanthochromia (yellow-tinged CSF from bilirubin in blood breakdown) or elevated red blood cells. Other red flag headache features include: new headache in patients >50, headache with fever/meningismus (meningitis), headache with focal neurological deficits, or headache in a patient with known aneurysm or coagulopathy. SAH has a 50% mortality rate and early neurosurgical intervention can be lifesaving.

Question 35: Which of the following is an example of a stroke mimic that can be rapidly excluded by checking blood glucose?

Brain tumor
Hypoglycemia (low blood sugar causing focal neurological deficits) (Correct answer)
Todd's paralysis
Hemiplegic migraine

Correct answer: Hypoglycemia (low blood sugar causing focal neurological deficits)

Hypoglycemia can cause focal neurological deficits identical to stroke; a bedside glucose check and glucose administration can rapidly distinguish and treat this mimic.

Hypoglycemia (blood glucose <50-60 mg/dL) can cause focal neurological deficits including hemiplegia, aphasia, and visual disturbances that are clinically indistinguishable from stroke. This is why blood glucose measurement is part of the initial prehospital and emergency stroke assessment. If hypoglycemia is found and treated (IV dextrose), symptoms typically resolve within minutes, excluding stroke. Hypoglycemia is one of the few stroke mimics that can be definitively and rapidly excluded with a simple bedside test. EMS providers are trained to check glucose in any patient with stroke-like symptoms. Failure to identify hypoglycemia as a stroke mimic could result in inappropriate tPA administration, which could be harmful in a non-stroke patient.

Question 36: What is the significance of 'time since last known well' when an ischemic stroke patient presents with an unknown onset (e.g., wake-up stroke)?

Unknown onset means the patient cannot receive any treatment
The last known well time is used as the therapeutic window baseline; wake-up strokes may qualify for thrombectomy with advanced imaging showing viable penumbra (Correct answer)
Unknown onset patients always receive tPA at maximum dose
Treatment is the same regardless of onset time

Correct answer: The last known well time is used as the therapeutic window baseline; wake-up strokes may qualify for thrombectomy with advanced imaging showing viable penumbra

Wake-up strokes use last known well as the time baseline; advanced MRI imaging (DWI-FLAIR mismatch) can identify patients within the effective treatment window.

Approximately 15-25% of ischemic strokes are wake-up strokes or unwitnessed strokes with unknown onset time. Because tPA has a defined 4.5-hour treatment window from last known well (LKW), patients who wake up with stroke symptoms could theoretically be hours beyond the tPA window. The WAKE-UP trial (2018) demonstrated that MRI DWI-FLAIR mismatch (visible ischemic lesion on diffusion-weighted imaging but no signal change on FLAIR) identifies patients who had their stroke within the past 4.5 hours, enabling safe tPA administration. For thrombectomy in LVO, the DAWN and DEFUSE 3 trials established that CT/MRI perfusion imaging showing a large penumbra with small core (mismatch) can identify thrombectomy candidates up to 24 hours from LKW.

CPR Stroke Recognition and Response 1

What does the acronym 'FAST' stand for in stroke recognition?

🃏 CPR Flashcards — Study This Quiz as Flip Cards →

📚 Want to go deeper? Read the Full CPR Study Guide →