Acute Ischemic Stroke

complete reference · tPA/TNK + thrombectomy criteria · permissive HTN · secondary prevention · ICU triggers · Full Card

Symptoms / Associated Sx

• Sudden, focal, negative neuro deficit corresponding to a vascular territory: unilateral arm/leg weakness, facial droop (forehead spared = central), aphasia (dominant MCA), hemineglect/gaze deviation (non-dominant MCA), homonymous hemianopia, dysarthria, ataxia/vertigo/diplopia (posterior circulation). Posterior strokes underscore on NIHSS — "dizziness + can't walk" with normal NIHSS still needs MRI.

• Last-known-well (LKW) is the single most important historical point — it defines the treatment window, NOT when symptoms were discovered (wake-up strokes default to time last seen normal). Establish from patient, family, EMS, timestamps (text messages, calls).

• NIHSS quantifies severity (0–42); also screens for LVO — NIHSS ≥6 with cortical signs (gaze deviation, neglect, aphasia) predicts large-vessel occlusion.

Neg

• Pt denies thunderclap/severe headache + vomiting + depressed LOC at onset — argues against ICH/SAH (non-con head CT is mandatory and rules this out before any thrombolytic; ischemic stroke is usually painless)

• No witnessed generalized seizure preceding the deficit, and NIHSS is not improving — argues against Todd paralysis (post-ictal weakness resolves over minutes-hours; if seizure witnessed, tPA risk/benefit shifts — but seizure at onset is no longer an absolute contraindication per 2019 AHA if disabling deficit attributable to ischemia)

• Onset was abrupt, not gradual with spreading positive visual/sensory phenomena — argues against complicated migraine (aura marches over minutes, positive symptoms, younger patient, prior identical episodes)

• POC glucose is 60–400 — argues against hypo/hyperglycemic mimic (hypoglycemia reproduces focal deficits; ALWAYS check glucose before CT/tPA, treat, then re-examine)

• No fever, meningismus, or diffuse encephalopathy — argues against CNS infection/sepsis unmasking an old deficit

Social History (SHx)

• Tobacco and alcohol use; stimulant/cocaine use (vasospasm, young stroke, dissection).

• Medication adherence — antihypertensives, and critically any anticoagulant with last dose timing (DOAC <48h or therapeutic warfarin contraindicates tPA).

• Prior stroke/TIA, AF, recent surgery/trauma/bleeding (tPA exclusions); functional baseline (drives rehab goals).

Main Etiology

• Large-artery atherosclerosis (carotid, intracranial). Cardioembolic — AF is the leading cause; also LV thrombus, valvular disease, endocarditis. Small-vessel/lacunar (chronic HTN, DM — pure motor/sensory syndromes). Cryptogenic (~25%, includes ESUS). Less common: arterial dissection (young, neck pain/trauma), hypercoagulable states, vasculitis, PFO with paradoxical embolism.

RF

• Modifiable: HTN (strongest), AF, diabetes, smoking, hyperlipidemia, carotid stenosis, OSA, sedentary/obesity.

• Non-modifiable: age, male sex, prior stroke/TIA, family history, sickle cell.

• Emerging: PFO (cryptogenic in young), chronic inflammation, COVID-associated hypercoagulability.

Data

• STAT non-contrast head CT (first step — excludes hemorrhage; identifies early ischemic changes, hyperdense vessel sign; ASPECTS score guides thrombectomy)

• POC glucose (checked before imaging — reversible mimic)

• CTA head and neck (detects LVO for thrombectomy; also dissection, stenosis, aneurysm)

• CT perfusion or MRI/MRA (quantifies ischemic core vs salvageable penumbra — gates extended-window thrombectomy 6–24h)

• NIHSS (severity, tPA decision support, serial trending for decline)

• ECG + continuous telemetry (AF — present or paroxysmal; ≥24–48h monitoring, consider extended for ESUS)

• CBC, INR/PTT (platelets >100k and INR <1.7 required for tPA); BMP, troponin

• A1c, fasting lipids (secondary prevention targets)

• TTE with agitated-saline (bubble) study (cardioembolic source, LV thrombus, PFO/ASD); carotid duplex if CTA equivocal

DDx

ICH / SAH (blood on non-con CT — the reason CT precedes tPA) · hypoglycemia (POC glucose; reverses with dextrose) · seizure with Todd paralysis (witnessed convulsion, post-ictal, deficit improving) · complicated/hemiplegic migraine (young, aura, recurrent, positive symptoms) · Bell palsy (forehead involved = peripheral CN VII, isolated) · functional/conversion (non-anatomic, give-way weakness, Hoover sign) · toxic-metabolic encephalopathy unmasking old deficit (fever, infection, global confusion)

Home Meds

• Hold home antihypertensives acutely if tPA-eligible or pursuing permissive hypertension.

• Continue statin (and intensify to high-dose).

• Clarify/hold anticoagulants — establish exact last dose of apixaban (Eliquis)/rivaroxaban (Xarelto)/warfarin (Coumadin); recent therapeutic anticoagulation is a tPA contraindication.

Plan

Consults

• Neurology / stroke team — activate immediately (code stroke); drives tPA and thrombectomy decisions.

• Neuro-interventional / endovascular — emergent if CTA confirms LVO.

• Neurosurgery — for hemorrhagic conversion, malignant MCA/cerebellar edema, or hydrocephalus.

• Vascular surgery — symptomatic carotid stenosis for CEA evaluation.

• SLP — formal dysphagia evaluation before any oral intake/meds.

• PT / OT — early mobilization and rehab disposition.

• Cardiology — if AF/cardioembolic source or PFO closure considered.

Reperfusion

• IV thrombolysis ≤4.5h from LKW (no contraindications): alteplase (Activase) 0.9 mg/kg IV, max 90 mg — 10% as bolus over 1 min, remainder over 60 min. Alternative: tenecteplase (TNKase) 0.25 mg/kg IV single bolus, max 25 mg (non-inferior, simpler — AHA 2019 reasonable, preferred pre-thrombectomy).

• Endovascular thrombectomy for anterior LVO (ICA, M1, selected M2): standard window ≤6h; extended 6–24h if favorable perfusion/clinical mismatch (DAWN, DEFUSE-3 showed benefit in selected patients). Give tPA first if eligible — do not skip; do not delay IR transfer for non-essential labs.

Blood pressure

• BP gate to GIVE tPA — must be <185/110. If above, lower with labetalol (Trandate) 10–20 mg IV push (may repeat ×1) or nicardipine (Cardene) 5 mg/h IV gtt, titrate by 2.5 mg/h q5–15min. If it cannot be brought and held <185/110, the patient is not eligible — do not give tPA.

• After tPA is administered — maintain <180/105 for 24h. Same agents; tighter ceiling specifically to reduce hemorrhagic transformation. Frequent neuro + BP checks per protocol.

• No reperfusion therapy (permissive HTN): do not treat unless >220/120, or concurrent AMI/aortic dissection/ICH/pre-eclampsia/heart failure — then lower ~15% in the first 24h.

Antithrombotics

• Aspirin (Bayer) 325 mg ×1 then 81 mg PO daily — start within 24–48h; if tPA given, wait 24h and confirm no hemorrhage on repeat CT.

• Minor stroke (NIHSS ≤3) or high-risk TIA: short-term DAPT — aspirin + clopidogrel (Plavix) 300–600 mg load then 75 mg daily ×21 days, then single agent (CHANCE/POINT reduced recurrent stroke; bleeding rises beyond 21–90 days).

• Anticoagulation for cardioembolic/AF: apixaban (Eliquis) 5 mg BID (or per renal/criteria) — timing by infarct size: roughly day 1 (TIA), 3 (small), 6 (moderate), 12 (large) — the "1-3-6-12" rule; start oral DOAC, no bridge needed.

Supportive / prevention

• Atorvastatin (Lipitor) 80 mg PO daily (SPARCL — high-intensity statin reduced recurrent stroke).

• NPO until bedside dysphagia screen passed; formal SLP swallow eval — aspiration is a major early cause of morbidity.

• Glucose target 140–180 mg/dL (avoid both hypo- and hyperglycemia); maintain normothermia (acetaminophen).

• VTE prophylaxis: SCDs immediately; add enoxaparin (Lovenox) 40 mg SC daily after 24h (and after confirming no hemorrhage post-tPA).

• Symptomatic carotid stenosis >70%: CEA or carotid stenting evaluation (ideally within 2 weeks). Workup for AF (extended monitoring if ESUS), PFO closure consideration in young cryptogenic.

Always

• PT / OT / SLP eval and treat — early mobilization as tolerated, functional assessment, formal swallow evaluation, inpatient-rehab vs SNF disposition planning.

• Trend daily: NIHSS (q1h ×first hours per tPA protocol → q4h); POC glucose; BP per protocol (q15min ×2h post-tPA); repeat non-con CT at 24h before starting antiplatelet/anticoagulant; daily neuro exam for decline.

• Escalation triggers: NIHSS ↑≥4 or new decline → STAT non-con CT (hemorrhagic conversion → hold all antithrombotics, neurosurgery) · GCS drop/airway threat → intubation + ICU · BP refractory to bolus needing continuous IV titration → ICU · large MCA/cerebellar infarct with mass effect → neurosurgery for hemicraniectomy/decompression.

• Discharge checklist: aspirin (Bayer) 81 mg daily ± clopidogrel (Plavix) 75 mg ×21d, or apixaban (Eliquis) if AF · atorvastatin (Lipitor) 80 mg daily · BP regimen (e.g. lisinopril/amlodipine) · A1c-guided diabetes control · smoking cessation · neurology follow-up 1–4 weeks · carotid/cardiac follow-up as indicated · driving restriction counseling · stroke-education + return precautions (recurrent deficit → call 911).

Red Flags — ICU / Neurosurgery

• Hemorrhagic conversion — sudden ↑NIHSS, headache, ↓LOC after tPA → STAT CT, stop antithrombotics, cryoprecipitate/tranexamic acid, neurosurgery.
• Malignant MCA edema — declining LOC, anisocoria, midline shift, usually 2–5 days post large infarct → hyperosmolar therapy + decompressive hemicraniectomy (<60y, within 48h, improves survival — DESTINY/DECIMAL/HAMLET).
• Cerebellar infarct with swelling — 4th-ventricle compression/hydrocephalus, brainstem signs → suboccipital decompression / EVD.
• Airway/aspiration, depressed GCS → intubate, ICU.
• Basilar occlusion — fluctuating deficits, ↓consciousness, crossed signs → emergent thrombectomy regardless of NIHSS.

Senior IM Resident Pearls

• Time is brain. ~1.9 million neurons lost per minute. The two clock-driven decisions are tPA/TNK (≤4.5h) and thrombectomy (≤6h, or ≤24h with perfusion mismatch). Everything else can wait — get LKW and the CT first.
• Glucose before everything. Hypoglycemia is the great stroke mimic. Check POC glucose before CT, treat, re-examine. A "stroke" that resolves with D50 was never a stroke.
• NIHSS underweights the posterior circulation. A patient with isolated vertigo + truncal ataxia can have a disabling cerebellar/basilar stroke and an NIHSS of 1–2. Don't let a low score talk you out of imaging.
• tPA contraindications worth memorizing: ICH ever, ischemic stroke/severe head trauma <3 months, active internal bleeding, BP >185/110 refractory, platelets <100k, INR >1.7, therapeutic DOAC <48h, recent major surgery, GI bleed/malignancy. Relative: minor/rapidly-improving deficits, glucose <50 or >400.
• Permissive hypertension is therapeutic, not neglect. In the non-lysed patient, BP supports penumbral perfusion. Aggressively lowering it extends the infarct. Only treat >220/120 or for a competing indication.
• DAPT is time-limited. CHANCE/POINT support aspirin + clopidogrel for minor stroke/high-risk TIA, but only for ~21 days — beyond that, bleeding outweighs benefit. Don't send them home on indefinite dual therapy.
• Anticoagulation timing for AF is size-dependent (1-3-6-12 rule) — anticoagulating a large infarct too early risks hemorrhagic conversion. When in doubt, image first and start later.
• Common mistake: ordering tPA labs and waiting for all of them before treating. Only glucose and (if anticoagulant suspected) coags are truly required — don't let a pending CBC burn the window.
• Common mistake: forgetting the swallow screen and ordering a diet — aspiration pneumonia is a leading early complication and a preventable readmission.