Stroke: Ischemic vs Hemorrhagic, FAST Warning Signs, and Treatment

795,000 Strokes Per Year: A Neurological Emergency by the Minute

Approximately 795,000 people in the United States experience a stroke each year — one every 40 seconds. Stroke is the fifth leading cause of death in the US and the leading cause of long-term adult disability. The phrase "time is brain" is not rhetorical: an untreated ischemic stroke destroys approximately 1.9 million neurons per minute. A patient who receives timely thrombolytic treatment averages 30 days of additional disability-free life per minute gained in treatment. This calculation makes stroke one of the most time-sensitive emergencies in medicine — not just compared to other neurological conditions, but compared to nearly any medical event.

Of the 795,000 annual US strokes, approximately 87% are ischemic strokes (caused by arterial blockage) and 13% are hemorrhagic strokes (caused by bleeding into or around the brain). These two broad categories have fundamentally different mechanisms, different emergency treatments, and substantially different outcomes — which is why distinguishing them within minutes is the first priority of acute stroke management.

FAST and BE-FAST: Recognizing Stroke Symptoms

The FAST acronym — Face drooping, Arm weakness, Speech difficulty, Time to call 911 — was developed to help the public identify the most common stroke symptoms. The expanded BE-FAST adds Balance loss and Eyes (sudden vision changes) to the front of the acronym, capturing posterior circulation strokes that the original FAST criteria miss. Studies suggest BE-FAST identifies up to 95% of strokes, compared to approximately 88% for FAST alone.

• Balance — sudden loss of balance or coordination
• Eyes — sudden blurred vision, double vision, or loss of vision in one or both eyes
• Face — sudden facial drooping, especially on one side; ask the person to smile
• Arms — sudden arm weakness or numbness; ask the person to raise both arms
• Speech — sudden slurred speech, difficulty finding words, or inability to understand
• Time — call 911 immediately; note the time symptoms began

The time of symptom onset — or the time the patient was last known to be well — is critical information for treatment eligibility. Every minute counts here.

Ischemic Stroke: Mechanisms and Subtypes

Ischemic stroke results from arterial occlusion depriving brain tissue of oxygen and glucose. The TOAST classification identifies five etiologic subtypes: large artery atherosclerosis (plaque in carotid, vertebral, or large intracranial arteries), cardioembolism (clots from atrial fibrillation, valvular disease, or left ventricular thrombus), small vessel occlusion (lacunar infarcts from arteriole disease), stroke from other determined etiology, and stroke of undetermined etiology (cryptogenic). The distinction matters because secondary prevention strategies differ dramatically: atrial fibrillation requires anticoagulation; large artery disease requires antiplatelet therapy plus risk factor modification; cardioembolic and cryptogenic strokes may benefit from extended cardiac monitoring to detect paroxysmal atrial fibrillation.

tPA Thrombolysis: The 4.5-Hour Window

Intravenous tissue plasminogen activator (tPA, alteplase) is the standard pharmacological treatment for acute ischemic stroke within 4.5 hours of symptom onset. tPA dissolves the clot by activating plasminogen, restoring blood flow. In eligible patients, tPA improves outcomes: treated patients are 30% more likely to have minimal or no disability at 3 months compared to placebo-treated patients.

The absolute contraindications to tPA are substantial and must be screened rapidly:

• Active internal bleeding or known bleeding diathesis
• Recent (within 3 months) head trauma, intracranial/spinal surgery, or prior stroke
• Current intracranial neoplasm, arteriovenous malformation, or aneurysm
• Blood pressure persistently above 185/110 mmHg despite antihypertensive treatment
• Serum glucose below 50 mg/dL (hypoglycemia alone can mimic stroke)
• CT evidence of hemorrhage or extensive early ischemic change

The most feared complication is symptomatic intracranial hemorrhage (sICH), occurring in approximately 6% of tPA-treated patients — a trade-off that requires careful patient selection.

Mechanical Thrombectomy: Extended Windows and Trial Evidence

Mechanical thrombectomy (MT) — catheter-based retrieval of clots from large cerebral arteries — has expanded the treatment window beyond what pharmacological thrombolysis can reach. Two landmark trials defined the extended window. The DAWN trial (2018) established that thrombectomy for anterior circulation large vessel occlusions is beneficial up to 24 hours from symptom onset in patients with a clinical-imaging mismatch — a large volume of potentially salvageable brain relative to the infarct core. The DEFUSE 3 trial (2017) established benefit up to 16 hours with perfusion imaging selection. These studies more than tripled the population eligible for potentially curative intervention.

Modern thrombectomy using stent retrievers achieves recanalization in approximately 85–90% of cases. Among patients with large vessel occlusion who receive thrombectomy within appropriate time and selection criteria, approximately 46% achieve functional independence (modified Rankin Scale 0–2) at 90 days — compared to 27% with medical management alone. The intervention is not a guarantee, but the magnitude of benefit is among the largest in acute medicine.

Hemorrhagic Stroke: Blood Pressure Management

Hemorrhagic strokes — intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH) — cannot be treated with thrombolytics. In ICH, a ruptured cerebral blood vessel bleeds into brain tissue; in SAH, bleeding occurs in the subarachnoid space, usually from a ruptured aneurysm. ICH is associated with a 30-day mortality of 40–50% and significant long-term disability in survivors.

Acute blood pressure management in ICH has been refined by the INTERACT2 and ATACH-2 trials. Current guidelines recommend rapidly lowering systolic blood pressure to 140 mmHg or less in patients presenting with acute ICH and systolic pressure between 150–220 mmHg — a target achievable with IV nicardipine or labetalol. More aggressive reduction to below 140 mmHg did not improve outcomes in ATACH-2 and was associated with harm. Reversal of anticoagulation is urgent in patients on warfarin (with 4-factor PCC) or direct oral anticoagulants (with specific reversal agents where available).

NIHSS: Quantifying Stroke Severity

Secondary Prevention: Anticoagulation vs. Antiplatelet Selection

Secondary prevention strategy depends entirely on stroke mechanism. Atrial fibrillation — responsible for 20–30% of ischemic strokes — requires anticoagulation, preferably with a direct oral anticoagulant (DOAC: apixaban, rivaroxaban, or dabigatran) rather than warfarin, given superior efficacy and safety profiles in clinical trials. Patients with non-cardioembolic ischemic stroke (atherosclerotic, small vessel, or cryptogenic) benefit from antiplatelet therapy — aspirin alone, clopidogrel alone, or dual antiplatelet therapy with aspirin plus clopidogrel for 21 days (POINT/CHANCE trial evidence). Combining anticoagulants with aspirin increases bleeding risk without adding benefit in most non-AF patients. Treatment must match mechanism, and mechanism requires investigation. Treating all strokes identically is a clinical error.