Stroke Types: Ischemic vs Hemorrhagic, NIH Stroke Scale, and tPA Eligibility for Nursing Students
A clinical-nursing reference for distinguishing ischemic vs hemorrhagic stroke, applying the NIH Stroke Scale, and recognizing tPA inclusion and exclusion criteria — the framework for the time-critical first hour of stroke care.
Learning Objectives
- ✓Distinguish ischemic from hemorrhagic stroke clinically and on imaging.
- ✓Apply the NIH Stroke Scale (NIHSS) to quantify deficit severity.
- ✓Recognize tPA inclusion and exclusion criteria for time-critical decisions.
1. Direct Answer: Ischemic vs Hemorrhagic Stroke
Stroke = sudden neurologic deficit from cerebral vascular cause. Two categories: ISCHEMIC (87% of strokes) — vessel occlusion blocks blood flow, causing infarction. Subtypes: thrombotic (atherosclerotic plaque rupture), embolic (cardiac source like atrial fibrillation), or lacunar (small vessel disease). HEMORRHAGIC (13%) — vessel rupture causes bleeding into brain parenchyma (intracerebral hemorrhage) or subarachnoid space (subarachnoid hemorrhage from aneurysm rupture). The two cannot be distinguished clinically with high reliability — non-contrast head CT is the immediate test to differentiate (hemorrhage shows as hyperdense on CT). This distinction is time-critical because ischemic stroke can be treated with tPA (thrombolytics) within a narrow window, but tPA is contraindicated in hemorrhagic stroke (would worsen bleeding).
Key Points
- •87% ischemic, 13% hemorrhagic.
- •Non-contrast head CT distinguishes (hemorrhage hyperdense, ischemia initially normal).
- •tPA only for ischemic — contraindicated in hemorrhagic.
- •Differentiation is immediate priority on arrival.
2. Ischemic Stroke Subtypes and Risk Factors
THROMBOTIC: atherosclerosis at vessel bifurcations (carotid, MCA stems), usually associated with hypertension, diabetes, hyperlipidemia, smoking. Often preceded by TIAs. Symptom onset typically gradual or stuttering. EMBOLIC: emboli typically from cardiac source (atrial fibrillation, prosthetic valve, mural thrombus post-MI, endocarditis vegetation). Symptom onset abrupt and at maximum severity initially. LACUNAR: small-vessel hypertensive disease producing small subcortical infarcts in basal ganglia, thalamus, internal capsule, pons. Classic syndromes: pure motor hemiparesis (internal capsule lacune), pure sensory stroke (thalamic), ataxic hemiparesis. Risk-factor management is the foundation of stroke prevention: BP control, statin, glycemic control, smoking cessation, anticoagulation for atrial fibrillation (CHA2DS2-VASc score).
Key Points
- •Thrombotic: atherosclerotic, gradual onset, TIA prodrome.
- •Embolic: cardiac source, abrupt onset at max severity.
- •Lacunar: hypertensive small-vessel disease, classic syndromes.
- •Prevention: BP, statin, glycemic control, anticoagulation for AFib.
3. Hemorrhagic Stroke Categories
INTRACEREBRAL HEMORRHAGE (ICH, 10% of strokes): bleeding into brain parenchyma, usually from hypertensive small-vessel rupture in basal ganglia, thalamus, pons, cerebellum. Symptoms include sudden severe headache, decreased level of consciousness, focal deficits depending on location. SUBARACHNOID HEMORRHAGE (SAH, 3%): bleeding into the subarachnoid space, usually from saccular (berry) aneurysm rupture at circle of Willis. Classic: "worst headache of life" thunderclap onset, photophobia, neck stiffness (meningismus). Diagnosed by non-contrast head CT (hyperdense in basal cisterns); if CT negative but suspicion high, lumbar puncture for xanthochromia. SAH carries 50% mortality, and survivors face vasospasm risk 3-14 days post-bleed.
Key Points
- •ICH: hypertensive bleed into parenchyma; common in basal ganglia.
- •SAH: aneurysmal bleed into subarachnoid space; thunderclap headache.
- •SAH on CT: hyperdense in basal cisterns.
- •Vasospasm risk 3-14 days post-SAH.
4. NIH Stroke Scale (NIHSS)
11 items scored 0 to maximum total of 42. Higher = worse deficit. Items: level of consciousness (3 sub-items), gaze, visual fields, facial palsy, motor arm (2: left and right), motor leg (2: left and right), limb ataxia, sensory, language, dysarthria, extinction/inattention. NIHSS <5 = minor stroke, 5-15 = moderate, 16-20 = severe, >20 = very severe. NIHSS is used to (1) document baseline deficit, (2) track changes over time, (3) make tPA decisions (most centers use NIHSS ≥4 as a tPA threshold to balance risk-benefit), and (4) communicate severity in handoffs ("NIHSS of 12"). Memorize the major components even if you don't calculate scores routinely — knowing what to assess is the bedside skill.
Key Points
- •11 items, total 0-42.
- •Higher = worse stroke.
- •Used for triage, tPA decisions, and serial monitoring.
- •Stratification: <5 minor, 5-15 moderate, 16-20 severe, >20 very severe.
5. tPA: Inclusion and Exclusion Criteria
Tissue plasminogen activator (alteplase) is the FDA-approved thrombolytic for acute ischemic stroke. INCLUSION: acute ischemic stroke with measurable deficit (typically NIHSS ≥4), symptom onset within 4.5 hours (3 hours is the original FDA window; 3-4.5 hours requires additional criteria), age ≥18. EXCLUSIONS (any one excludes tPA): hemorrhage on CT, history of intracranial hemorrhage, recent stroke within 3 months, recent major surgery within 14 days, BP >185/110 not controlled, INR >1.7 or anticoagulation, platelet count <100,000, blood glucose <50 mg/dL, evidence of active bleeding. The 4.5-hour window is the most consequential nursing knowledge — confirm exact symptom onset time (or last known well time) and document precisely. Mechanical thrombectomy extends the window to 24 hours for large vessel occlusion meeting imaging criteria (DAWN, DEFUSE 3 trials).
Key Points
- •Window: 4.5 hours from symptom onset (or last known well).
- •Hemorrhage on CT excludes immediately.
- •BP >185/110, INR >1.7, glucose <50 are common exclusions.
- •Mechanical thrombectomy extends window to 24 hours with imaging criteria.
6. Time-Critical Nursing Priorities
First hour priorities: (1) ABC assessment — airway protection if decreased LOC. (2) Vital signs — BP must be measured and addressed before tPA decision. (3) Non-contrast head CT — within 25 minutes of arrival per AHA guidelines. (4) Lab draws — CBC, BMP, PT/INR, glucose, type and screen. (5) IV access — two large-bore. (6) NIHSS — quantify deficit. (7) Time of symptom onset — confirmed with witness or last-known-well. (8) Code Stroke activation — neurology consult. (9) BP management — aim for <185/110 before tPA; labetalol or nicardipine commonly used. (10) After tPA: continuous neuro checks every 15 minutes for 2 hours, then every 30 minutes for 6 hours, then every hour for 16 hours. Any deterioration → emergent repeat CT to evaluate for hemorrhagic conversion.
Key Points
- •Door to CT: 25 minutes.
- •Two large-bore IVs, full labs, NIHSS, time of onset.
- •BP must be <185/110 before tPA.
- •Post-tPA: q15 min × 2 hr neuro checks, q30 min × 6 hr, q1 hr × 16 hr.
7. Using NurseIQ for Stroke Care Practice
Snap a photo of any stroke vignette or imaging report and NurseIQ identifies the likely stroke type (ischemic vs hemorrhagic), calculates the NIHSS based on the documented deficits, applies tPA inclusion/exclusion criteria, and walks through the time-critical nursing priorities. The app generates NCLEX-style practice cases at multiple difficulty levels.
Key Points
- •Stroke type identification from vignette.
- •NIHSS calculation.
- •tPA eligibility analysis with reasoning.
High-Yield Facts
- ★87% ischemic, 13% hemorrhagic; CT differentiates.
- ★tPA window: 4.5 hours from symptom onset (3 hr classic, 3-4.5 hr with criteria).
- ★Mechanical thrombectomy window: 24 hours for large vessel occlusion (DAWN/DEFUSE 3).
- ★NIHSS: 11 items, total 0-42.
- ★BP must be <185/110 for tPA candidacy.
- ★SAH: thunderclap headache, basal cistern hyperdensity on CT.
- ★Lacunar syndromes from small-vessel hypertensive disease.
Practice Questions
1. A patient presents with right-sided weakness, aphasia, and NIHSS of 14. Symptom onset 90 minutes ago. BP 170/95. INR 1.2. Glucose 110. CT shows no hemorrhage. tPA candidate?
2. Same patient but symptom onset 6 hours ago. tPA candidate?
3. A patient has sudden severe headache, photophobia, neck stiffness, and decreased LOC. Most likely diagnosis and next test?
FAQs
Common questions about this topic
TIA (transient ischemic attack) is a transient neurologic deficit from cerebral ischemia that resolves within 24 hours (usually within 1 hour) without permanent injury on imaging. A stroke is a deficit lasting longer than 24 hours or showing infarction on imaging. The distinction is increasingly imaging-based: any patient with neurologic symptoms and diffusion restriction on MRI has had a stroke regardless of symptom duration. TIAs predict subsequent stroke (10-15% risk within 90 days) and warrant urgent evaluation.
Most stroke patients have elevated BP at presentation (catecholamine surge, autoregulation impairment). Generally BP is NOT aggressively lowered in the first 24-48 hours because cerebral perfusion depends on it. Exceptions: BP >220/120 (or >185/110 for tPA candidates), aortic dissection, hypertensive emergency with end-organ damage. Aim for gradual lowering by no more than 15-25% in the first 24 hours.
Endovascular clot retrieval for large vessel occlusion (M1 MCA, ICA, basilar) within 6 hours of symptom onset (extended to 24 hours with favorable imaging on DAWN and DEFUSE 3 criteria). Has dramatically improved outcomes for large vessel occlusion strokes. tPA may be administered first as a bridge to thrombectomy. Time-critical: door-to-puncture target is 90 minutes.
Hemorrhagic conversion of ischemic stroke is the most feared complication, occurring in ~6% within 36 hours. Major systemic bleeding occurs in 1-2%. Risk increases with higher NIHSS, age, hyperglycemia, and longer time-to-treatment. Post-tPA monitoring: q15 min neuro checks for 2 hours, q30 min for 6 hours, then q1 hr for 16 hours; any deterioration → emergent CT.
Snap a photo of any stroke vignette and NurseIQ identifies the likely type, calculates the NIHSS, applies tPA criteria, and walks through the time-critical nursing priorities. The app generates NCLEX-style practice cases. This content is for educational purposes only and supports nursing student learning.