Ischemic stroke: Difference between revisions
(Major expansion: tPA dosing/contraindications, thrombectomy up to 24h (DAWN/DEFUSE3), tenecteplase, BP targets by scenario, NIHSS, LVO identification, drip-and-ship, HINTS, references with PMIDs) |
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==Background== | ==Background== | ||
* | *Acute ischemia of brain parenchyma due to arterial occlusion | ||
* | *Most common type of stroke (~87% of all strokes) | ||
*'''5th leading cause of death''' in the US; '''leading cause of long-term disability''' | *'''5th leading cause of death''' in the US; '''leading cause of long-term disability''' | ||
* | *"Time is brain": ~1.9 million neurons lost per minute of untreated large vessel occlusion<ref>Saver JL. Time is brain — quantified. ''Stroke''. 2006;37(1):263-266. PMID 16339467</ref> | ||
* | *IV tPA window: up to 4.5 hours from last known well | ||
* | *Thrombectomy window: up to 24 hours in select patients with large vessel occlusion (LVO) and favorable imaging | ||
===Etiology=== | ===Etiology=== | ||
* | *Large artery atherosclerosis (~25%): carotid stenosis, intracranial atherosclerosis | ||
* | *Cardioembolism (~25%): [[atrial fibrillation]] (most common), valvular disease, LV thrombus | ||
* | *Small vessel disease (lacunar, ~20%): lipohyalinosis of penetrating arteries (hypertension) | ||
*'''Other determined''' (~5%): dissection, [[hypercoagulable state]], vasculitis, sickle cell | *'''Other determined''' (~5%): dissection, [[hypercoagulable state]], vasculitis, sickle cell | ||
* | *Cryptogenic/undetermined (~25%) | ||
==Clinical Features== | ==Clinical Features== | ||
* | *Sudden onset focal neurologic deficit (maximal at onset or rapidly progressive) | ||
* | *Last known well (LKW) time is the most critical historical datapoint | ||
===Anterior Circulation (Carotid Territory)=== | ===Anterior Circulation (Carotid Territory)=== | ||
* | *MCA stroke (most common): contralateral face/arm > leg weakness, hemisensory loss, aphasia (dominant hemisphere) or neglect (nondominant), gaze deviation toward lesion | ||
* | *ACA stroke: contralateral leg > arm weakness, urinary incontinence, abulia | ||
* | *ICA occlusion: entire MCA territory ± ACA territory | ||
===Posterior Circulation (Vertebrobasilar)=== | ===Posterior Circulation (Vertebrobasilar)=== | ||
* | *PCA stroke: homonymous hemianopia, memory deficits, alexia without agraphia | ||
*'''Basilar occlusion''' ('''emergency'''): bilateral motor/sensory deficits, cranial nerve palsies, coma, locked-in syndrome | *'''Basilar occlusion''' ('''emergency'''): bilateral motor/sensory deficits, cranial nerve palsies, coma, locked-in syndrome | ||
*'''Cerebellar stroke''': ataxia, vertigo, nystagmus, headache → '''can cause brainstem compression''' (surgical emergency) | *'''Cerebellar stroke''': ataxia, vertigo, nystagmus, headache → '''can cause brainstem compression''' (surgical emergency) | ||
* | *HINTS exam to distinguish cerebellar/brainstem stroke from peripheral vertigo | ||
===Mimics (Important to Recognize)=== | ===Mimics (Important to Recognize)=== | ||
*[[Hypoglycemia]] ( | *[[Hypoglycemia]] (always check glucose), seizure with Todd paralysis, [[Bell palsy]], migraine with aura, conversion disorder, intracranial mass | ||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
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===Critical First Steps=== | ===Critical First Steps=== | ||
*'''Blood glucose''' ('''POC STAT''' — hypoglycemia mimics stroke and must be corrected) | *'''Blood glucose''' ('''POC STAT''' — hypoglycemia mimics stroke and must be corrected) | ||
* | *Non-contrast CT head (rule out hemorrhage — ONLY test required before tPA) | ||
* | *CT angiography (CTA) head and neck: identify large vessel occlusion (LVO) for thrombectomy candidacy | ||
* | *CT perfusion (CTP): ischemic penumbra assessment for extended-window cases | ||
===NIHSS Score=== | ===NIHSS Score=== | ||
*Standardized neurologic exam scoring (0-42) | *Standardized neurologic exam scoring (0-42) | ||
*Correlates with stroke severity and helps guide treatment decisions | *Correlates with stroke severity and helps guide treatment decisions | ||
* | *NIHSS ≥6: consider LVO until proven otherwise; higher scores = worse prognosis | ||
*Use the [[NIHSS calculator]] for scoring | *Use the [[NIHSS calculator]] for scoring | ||
===Additional Studies=== | ===Additional Studies=== | ||
* | *ECG: atrial fibrillation, MI | ||
* | *CBC, BMP, coagulation studies (PT/INR, PTT) | ||
* | *Troponin (concurrent cardiac events) | ||
* | *A1c, lipid panel (risk factor assessment, not urgent) | ||
*Echocardiography (identify cardioembolic source) | *Echocardiography (identify cardioembolic source) | ||
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*CTA/CTP | *CTA/CTP | ||
*Complete history | *Complete history | ||
* | *Only glucose and NCCT are needed before tPA | ||
==Management== | ==Management== | ||
===IV Alteplase (tPA)=== | ===IV Alteplase (tPA)=== | ||
* | *Indicated within 4.5 hours of last known well (LKW)<ref>Powers WJ, et al. Guidelines for the early management of patients with acute ischemic stroke: 2019 update to the 2018 guidelines. ''Stroke''. 2019;50(12):e344-e418. PMID 31662037</ref> | ||
* | *Dose: 0.9 mg/kg IV (max 90 mg): | ||
** | **10% as bolus over 1 minute | ||
** | **Remaining 90% infused over 60 minutes | ||
* | *Extended window (3-4.5 hours): additional exclusions apply (age >80, NIHSS >25, oral anticoagulant use, history of DM + prior stroke) | ||
* | *Key contraindications: | ||
**Active internal bleeding, recent intracranial surgery/trauma (3 months) | **Active internal bleeding, recent intracranial surgery/trauma (3 months) | ||
**Intracranial hemorrhage on CT | **Intracranial hemorrhage on CT | ||
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**Platelets <100,000, INR >1.7, aPTT elevated | **Platelets <100,000, INR >1.7, aPTT elevated | ||
**Blood glucose <50 mg/dL | **Blood glucose <50 mg/dL | ||
* | *Tenecteplase (0.25 mg/kg IV bolus, max 25 mg): emerging alternative, single-bolus dosing, favorable in LVO<ref>Campbell BCV, et al. Tenecteplase versus alteplase before thrombectomy for ischemic stroke (EXTEND-IA TNK). ''N Engl J Med''. 2018;378(17):1573-1582. PMID 29694815</ref> | ||
===Endovascular Thrombectomy=== | ===Endovascular Thrombectomy=== | ||
* | *Standard window: within 6 hours of LKW for anterior LVO | ||
* | *Extended window: up to 24 hours with favorable perfusion imaging (DAWN and DEFUSE 3 trials)<ref>Nogueira RG, et al. Thrombectomy 6 to 24 hours after stroke with a mismatch between deficit and infarct (DAWN). ''N Engl J Med''. 2018;378(1):11-21. PMID 29129157</ref> | ||
* | *Target vessels: ICA, M1, and sometimes M2 MCA, basilar artery | ||
* | *NNT = ~2.6 for reduced disability (one of the most effective treatments in medicine) | ||
*Thrombectomy is ADDITIVE to IV tPA — '''give tPA first, do not delay for thrombectomy''' | *Thrombectomy is ADDITIVE to IV tPA — '''give tPA first, do not delay for thrombectomy''' | ||
===Blood Pressure Management=== | ===Blood Pressure Management=== | ||
* | *If tPA candidate: lower BP to <185/110 before tPA; maintain <180/105 for 24h after | ||
* | *If NOT receiving tPA: permissive hypertension up to 220/120 (avoid aggressive lowering) | ||
* | *Post-thrombectomy with successful recanalization: target SBP <140 (BP-TARGET trial) | ||
*Preferred agents: labetalol, nicardipine | *Preferred agents: labetalol, nicardipine | ||
===General Management=== | ===General Management=== | ||
* | *NPO until swallow assessment (aspiration risk) | ||
* | *Aspirin 325 mg PO/PR within 24-48 hours (if no tPA in past 24h) | ||
*'''DVT prophylaxis''' (SCDs immediately; chemical prophylaxis after 24-48h) | *'''DVT prophylaxis''' (SCDs immediately; chemical prophylaxis after 24-48h) | ||
* | *Glucose management: target 140-180 mg/dL; treat hypoglycemia; avoid hyperglycemia | ||
* | *Avoid fever (antipyretics for temp >38°C) | ||
* | *Avoid hypotension (maintain adequate cerebral perfusion) | ||
==Disposition== | ==Disposition== | ||
* | *All acute stroke patients: admit to stroke unit/neuro ICU | ||
* | *Transfer to comprehensive stroke center if LVO identified and thrombectomy capability unavailable | ||
*'''Do NOT delay tPA for transfer''' — give tPA at presenting hospital then transfer ("drip and ship") | *'''Do NOT delay tPA for transfer''' — give tPA at presenting hospital then transfer ("drip and ship") | ||
*Neurology and neurointerventional consultation | *Neurology and neurointerventional consultation | ||
Latest revision as of 09:26, 22 March 2026
Background
- Acute ischemia of brain parenchyma due to arterial occlusion
- Most common type of stroke (~87% of all strokes)
- 5th leading cause of death in the US; leading cause of long-term disability
- "Time is brain": ~1.9 million neurons lost per minute of untreated large vessel occlusion[1]
- IV tPA window: up to 4.5 hours from last known well
- Thrombectomy window: up to 24 hours in select patients with large vessel occlusion (LVO) and favorable imaging
Etiology
- Large artery atherosclerosis (~25%): carotid stenosis, intracranial atherosclerosis
- Cardioembolism (~25%): atrial fibrillation (most common), valvular disease, LV thrombus
- Small vessel disease (lacunar, ~20%): lipohyalinosis of penetrating arteries (hypertension)
- Other determined (~5%): dissection, hypercoagulable state, vasculitis, sickle cell
- Cryptogenic/undetermined (~25%)
Clinical Features
- Sudden onset focal neurologic deficit (maximal at onset or rapidly progressive)
- Last known well (LKW) time is the most critical historical datapoint
Anterior Circulation (Carotid Territory)
- MCA stroke (most common): contralateral face/arm > leg weakness, hemisensory loss, aphasia (dominant hemisphere) or neglect (nondominant), gaze deviation toward lesion
- ACA stroke: contralateral leg > arm weakness, urinary incontinence, abulia
- ICA occlusion: entire MCA territory ± ACA territory
Posterior Circulation (Vertebrobasilar)
- PCA stroke: homonymous hemianopia, memory deficits, alexia without agraphia
- Basilar occlusion (emergency): bilateral motor/sensory deficits, cranial nerve palsies, coma, locked-in syndrome
- Cerebellar stroke: ataxia, vertigo, nystagmus, headache → can cause brainstem compression (surgical emergency)
- HINTS exam to distinguish cerebellar/brainstem stroke from peripheral vertigo
Mimics (Important to Recognize)
- Hypoglycemia (always check glucose), seizure with Todd paralysis, Bell palsy, migraine with aura, conversion disorder, intracranial mass
Differential Diagnosis
- Hemorrhagic stroke (cannot distinguish clinically — MUST image)
- Hypoglycemia
- Postictal (Todd) paralysis
- Complicated migraine
- Bell palsy
- Intracranial mass/abscess
- Psychogenic/conversion
- Drug toxicity
Evaluation
Critical First Steps
- Blood glucose (POC STAT — hypoglycemia mimics stroke and must be corrected)
- Non-contrast CT head (rule out hemorrhage — ONLY test required before tPA)
- CT angiography (CTA) head and neck: identify large vessel occlusion (LVO) for thrombectomy candidacy
- CT perfusion (CTP): ischemic penumbra assessment for extended-window cases
NIHSS Score
- Standardized neurologic exam scoring (0-42)
- Correlates with stroke severity and helps guide treatment decisions
- NIHSS ≥6: consider LVO until proven otherwise; higher scores = worse prognosis
- Use the NIHSS calculator for scoring
Additional Studies
- ECG: atrial fibrillation, MI
- CBC, BMP, coagulation studies (PT/INR, PTT)
- Troponin (concurrent cardiac events)
- A1c, lipid panel (risk factor assessment, not urgent)
- Echocardiography (identify cardioembolic source)
Do NOT Delay tPA for:
- Labs (except glucose)
- CTA/CTP
- Complete history
- Only glucose and NCCT are needed before tPA
Management
IV Alteplase (tPA)
- Indicated within 4.5 hours of last known well (LKW)[2]
- Dose: 0.9 mg/kg IV (max 90 mg):
- 10% as bolus over 1 minute
- Remaining 90% infused over 60 minutes
- Extended window (3-4.5 hours): additional exclusions apply (age >80, NIHSS >25, oral anticoagulant use, history of DM + prior stroke)
- Key contraindications:
- Active internal bleeding, recent intracranial surgery/trauma (3 months)
- Intracranial hemorrhage on CT
- SBP >185 or DBP >110 (lower BP first)
- Platelets <100,000, INR >1.7, aPTT elevated
- Blood glucose <50 mg/dL
- Tenecteplase (0.25 mg/kg IV bolus, max 25 mg): emerging alternative, single-bolus dosing, favorable in LVO[3]
Endovascular Thrombectomy
- Standard window: within 6 hours of LKW for anterior LVO
- Extended window: up to 24 hours with favorable perfusion imaging (DAWN and DEFUSE 3 trials)[4]
- Target vessels: ICA, M1, and sometimes M2 MCA, basilar artery
- NNT = ~2.6 for reduced disability (one of the most effective treatments in medicine)
- Thrombectomy is ADDITIVE to IV tPA — give tPA first, do not delay for thrombectomy
Blood Pressure Management
- If tPA candidate: lower BP to <185/110 before tPA; maintain <180/105 for 24h after
- If NOT receiving tPA: permissive hypertension up to 220/120 (avoid aggressive lowering)
- Post-thrombectomy with successful recanalization: target SBP <140 (BP-TARGET trial)
- Preferred agents: labetalol, nicardipine
General Management
- NPO until swallow assessment (aspiration risk)
- Aspirin 325 mg PO/PR within 24-48 hours (if no tPA in past 24h)
- DVT prophylaxis (SCDs immediately; chemical prophylaxis after 24-48h)
- Glucose management: target 140-180 mg/dL; treat hypoglycemia; avoid hyperglycemia
- Avoid fever (antipyretics for temp >38°C)
- Avoid hypotension (maintain adequate cerebral perfusion)
Disposition
- All acute stroke patients: admit to stroke unit/neuro ICU
- Transfer to comprehensive stroke center if LVO identified and thrombectomy capability unavailable
- Do NOT delay tPA for transfer — give tPA at presenting hospital then transfer ("drip and ship")
- Neurology and neurointerventional consultation
- Start workup for stroke etiology (echo, prolonged cardiac monitoring, vascular imaging)
See Also
- Hemorrhagic stroke
- Subarachnoid hemorrhage
- Transient ischemic attack
- NIHSS calculator
- Atrial fibrillation
- Stroke mimics
References
- ↑ Saver JL. Time is brain — quantified. Stroke. 2006;37(1):263-266. PMID 16339467
- ↑ Powers WJ, et al. Guidelines for the early management of patients with acute ischemic stroke: 2019 update to the 2018 guidelines. Stroke. 2019;50(12):e344-e418. PMID 31662037
- ↑ Campbell BCV, et al. Tenecteplase versus alteplase before thrombectomy for ischemic stroke (EXTEND-IA TNK). N Engl J Med. 2018;378(17):1573-1582. PMID 29694815
- ↑ Nogueira RG, et al. Thrombectomy 6 to 24 hours after stroke with a mismatch between deficit and infarct (DAWN). N Engl J Med. 2018;378(1):11-21. PMID 29129157
- Goyal M, et al. Endovascular thrombectomy after large-vessel ischaemic stroke: a meta-analysis. Lancet. 2016;387(10029):1723-1731. PMID 26898852
- Hacke W, et al. Thrombolysis with alteplase 3 to 4.5 hours after acute ischemic stroke (ECASS III). N Engl J Med. 2008;359(13):1317-1329. PMID 18815396