Ischemic Stroke

Quick Answer

Ischemic stroke is acute brain tissue infarction resulting from arterial occlusion (thrombotic or embolic), leading to focal neurological deficits. ICU management focuses on acute reperfusion therapy (IV alteplase within 4.5h, endovascular thrombectomy within 6-24h for large vessel occlusion), neuroprotective strategies (permissive hypertension unless thrombolysed, normoglycemia, normothermia), complication surveillance (malignant MCA syndrome, hemorrhagic transformation), and secondary prevention (antiplatelet therapy, anticoagulation for atrial fibrillation).

Time-critical interventions include NIHSS assessment, non-contrast CT brain, CT angiography, and rapid team activation for eligible patients.

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CICM Exam Focus

Written Exam

• SAQ topics: Indications/contraindications for thrombolysis and thrombectomy, blood pressure management post-stroke, management of malignant MCA syndrome, secondary prevention strategies
• MCQ topics: NIHSS scoring, TOAST classification, imaging interpretation (CT vs MRI), antiplatelet vs anticoagulation timing
• Common pitfalls: Incorrect BP targets (permissive hypertension vs strict control), early anticoagulation after large infarct, missing thrombectomy window, inappropriate ICP management

Viva Voce

• Scenarios: Acute stroke within thrombolysis window, large vessel occlusion requiring thrombectomy, malignant MCA syndrome with herniation, posterior circulation stroke
• Data interpretation: CT brain (hyperdense MCA sign, loss of grey-white differentiation, ASPECTS scoring), CT angiography (vessel occlusion site), CT perfusion (core vs penumbra)
• Management priorities: Time-to-treatment targets, BP management algorithms, reperfusion eligibility, airway protection, ICP monitoring indications
• Challenging questions: Thrombolysis in borderline cases (age greater than 80, NIHSS below 4 or greater than 25, recent surgery), wake-up stroke imaging criteria, blood pressure management in different scenarios

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Key Points

• Ischemic stroke accounts for 80-85% of all strokes; embolic (cardioembolic or large artery) and thrombotic (small vessel) etiologies
• NIHSS (National Institutes of Health Stroke Scale) score 0-42 quantifies stroke severity: 0 = no deficit, 1-4 = minor, 5-15 = moderate, 16-20 = moderate-severe, 21-42 = severe
• IV alteplase 0.9 mg/kg (10% bolus, 90% over 60 min) within 4.5 hours reduces disability (NNT = 7-10 for good outcome) but increases symptomatic ICH risk 6-7%
• Endovascular thrombectomy within 6 hours (up to 24h with perfusion imaging) for large vessel occlusion (ICA, M1, M2, basilar) achieves 50-70% recanalization, NNT = 3-7 for functional independence
• Permissive hypertension (allow SBP up to 220 mmHg, DBP up to 120 mmHg) unless thrombolysis given (then target SBP below 185/110 pre-lysis, below 180/105 post-lysis for 24h)
• Malignant MCA syndrome (large hemispheric infarct with mass effect) develops in 1-10% within 24-48h; mortality 80% without decompressive craniectomy, 20-30% with surgery
• Hemorrhagic transformation occurs in 5-10% spontaneously, 15-25% after thrombolysis (symptomatic ICH 6-7%); risk factors include large infarct size, late reperfusion, anticoagulation, hyperglycemia
• Dual antiplatelet therapy (aspirin 300 mg + clopidogrel 300 mg loading) within 24-48h for minor stroke/TIA (NIHSS ≤3) reduces recurrent stroke by 30% at 90 days
• Anticoagulation for atrial fibrillation should be delayed 1-3 days (minor stroke), 3-6 days (moderate), or 12-14 days (large stroke) to minimize hemorrhagic transformation risk
• Secondary prevention targets: BP below 130/80 mmHg, LDL-C below 1.8 mmol/L, HbA1c below 7%, smoking cessation, antiplatelet or anticoagulation therapy

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Epidemiology

Incidence and Prevalence

Ischemic stroke accounts for 80-85% of all strokes, with an annual incidence of 150-250 per 100,000 population in high-income countries (PMID: 31208453). Global stroke incidence has increased by 70% from 1990 to 2019, predominantly driven by aging populations and vascular risk factor prevalence (PMID: 33069326).

Age-specific incidence doubles every decade after age 55, rising from 30 per 100,000 (age 30-44) to 1,500 per 100,000 (age 75-84) (PMID: 28596432). Approximately 10-15% of ischemic strokes occur in individuals under 50 years ("young stroke"), often with distinct etiologies including dissection, vasculitis, hypercoagulable states, and paradoxical embolism (PMID: 27899503).

Intensive Care Admission

15-25% of ischemic stroke patients require ICU admission (PMID: 22821541), with indications including:

• Large hemispheric infarction at risk of malignant edema
• Posterior circulation stroke with brainstem involvement
• Post-thrombolysis or post-thrombectomy monitoring
• Airway compromise requiring intubation
• Hemodynamic instability
• Concurrent medical complications (aspiration pneumonia, cardiac arrhythmia)

ICU mortality for ischemic stroke ranges from 15-30%, significantly higher than general stroke mortality of 10-15% (PMID: 22821541). Predictors of ICU mortality include NIHSS greater than 20, ASPECTS score below 5, mechanical ventilation requirement, and development of malignant MCA syndrome.

Etiology Distribution (TOAST Classification)

The TOAST (Trial of Org 10172 in Acute Stroke Treatment) classification categorizes ischemic stroke into five subtypes (PMID: 8421980):

Cardioembolic stroke is increasingly recognized with improved detection of paroxysmal atrial fibrillation via prolonged cardiac monitoring (30-day event recorders detect AF in 16-23% of cryptogenic strokes) (PMID: 24744381).

Australian and New Zealand Context

In Australia, 56,000 strokes occur annually, with ischemic stroke comprising approximately 45,000 cases (Stroke Foundation Australia 2023). Indigenous Australians experience stroke at 2.5 times the rate of non-Indigenous Australians, with onset 15 years earlier on average (PMID: 30760144).

New Zealand reports 9,000 strokes annually, with Māori and Pacific Islander populations experiencing disproportionately higher incidence (Māori 1.7× higher) and younger age at onset (PMID: 28691157).

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Pathophysiology

Cerebral Blood Flow and Ischemic Cascade

Normal cerebral blood flow (CBF) is 50-60 mL/100g/min. Neurological dysfunction begins when CBF falls below 20-25 mL/100g/min (ischemic penumbra), and irreversible infarction occurs below 10-12 mL/100g/min (ischemic core) (PMID: 15166063).

The ischemic cascade progresses through sequential steps:

1. Energy failure (ATP depletion within minutes) → failure of Na⁺/K⁺-ATPase pumps
2. Anoxic depolarization → massive intracellular Na⁺ and Ca²⁺ influx, extracellular K⁺ accumulation
3. Excitotoxicity → glutamate release activates NMDA/AMPA receptors, exacerbating Ca²⁺ influx
4. Peri-infarct depolarization → spreading waves of depolarization expand infarct core into penumbra
5. Oxidative stress → mitochondrial dysfunction, reactive oxygen species (ROS) formation
6. Inflammation → microglial activation, cytokine release (IL-1β, TNF-α), leukocyte infiltration
7. Apoptosis and necrosis → caspase activation, DNA fragmentation, cell death

The ischemic penumbra represents salvageable brain tissue surrounding the infarct core where CBF is critically reduced but cellular integrity is maintained. The penumbra can survive for 4-6 hours (sometimes 24 hours with good collaterals), forming the therapeutic window for reperfusion therapy (PMID: 16847063).

Collateral Circulation

Leptomeningeal collaterals connect distal branches of the anterior, middle, and posterior cerebral arteries, providing critical alternative blood supply during proximal vessel occlusion. Good collateral status is associated with:

• Slower infarct growth (core expansion 3-5 mL/h vs 10-15 mL/h with poor collaterals)
• Larger penumbra-to-core ratio
• Better response to reperfusion therapy
• Improved functional outcomes (PMID: 23204507)

Collateral grading on CT angiography or digital subtraction angiography:

• Grade 0: No collaterals
• Grade 1: Minimal collaterals (filling below 50% of MCA territory)
• Grade 2: Moderate collaterals (50-99% filling)
• Grade 3: Complete collaterals (100% filling)

Large Vessel Occlusion Hemodynamics

Proximal large vessel occlusion (LVO) includes internal carotid artery (ICA) terminus, M1 and proximal M2 segments of middle cerebral artery, and basilar artery. LVO accounts for 30-40% of ischemic strokes but is responsible for the majority of severe strokes (NIHSS greater than 10) and malignant MCA syndromes (PMID: 29129157).

LVO strokes demonstrate:

• Larger initial infarct volumes (median 30-50 mL vs 5-10 mL for distal occlusions)
• Faster infarct growth rates (10-15 mL/h vs 2-5 mL/h)
• Lower rates of spontaneous recanalization (5-10% vs 30-40%)
• Higher disability rates without intervention (70-80% mRS 3-6 vs 30-40%)

Hemorrhagic Transformation

Hemorrhagic transformation (HT) results from reperfusion injury to ischemic endothelium, with disruption of the blood-brain barrier allowing extravasation of red blood cells. Two main patterns (PMID: 20160752):

1. Hemorrhagic infarction (HI): Petechial hemorrhage within infarcted tissue (HI-1 small petechiae, HI-2 confluent petechiae); usually asymptomatic
2. Parenchymal hematoma (PH): Frank hematoma with mass effect (PH-1 hematoma below 30% of infarct, PH-2 hematoma greater than 30% of infarct); often symptomatic

Symptomatic intracerebral hemorrhage (sICH) occurs in:

• 5-10% after thrombolysis (vs 1-2% without thrombolysis) (PMID: 7477192)
• 4-6% after thrombectomy (PMID: 25622020)
• Associated with worse outcomes: mortality 40-60%, mRS 5-6 in 60-80%

Risk factors for HT:

• Large infarct size (ASPECTS ≤5)
• Late reperfusion (greater than 6 hours)
• Anticoagulation therapy
• Hyperglycemia (glucose greater than 10 mmol/L)
• Severe hypertension (SBP greater than 180 mmHg)
• Leukoaraiosis (white matter disease)

Cerebral Edema and Malignant MCA Syndrome

Cytotoxic edema develops within hours due to cellular energy failure and osmotic swelling. Vasogenic edema follows blood-brain barrier disruption at 24-72 hours. Malignant MCA syndrome describes massive hemispheric infarction (greater than 50% of MCA territory) with life-threatening edema and mass effect (PMID: 19246704).

Malignant MCA syndrome characteristics:

• Occurs in 1-10% of ischemic strokes
• Peak edema and maximal ICP at 48-96 hours post-stroke
• Clinical deterioration: drowsiness → stupor → coma, with ipsilateral pupil dilation
• Uncal herniation → compression of posterior cerebral artery → ipsilateral PCA infarction, contralateral hemiparesis
• Mortality 80% with medical management alone, 20-30% with decompressive craniectomy

Predictors of malignant edema:

• ASPECTS score ≤5
• Infarct volume greater than 145 mL on diffusion-weighted MRI
• NIHSS greater than 20
• Nausea and vomiting at presentation
• Younger age (below 60 years) paradoxically at higher risk due to limited skull compliance

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Clinical Presentation

NIHSS (National Institutes of Health Stroke Scale)

The NIHSS is a 15-item standardized neurological examination quantifying stroke severity (score 0-42) (PMID: 2467198). Higher scores correlate with larger infarcts, lower recanalization rates, and worse outcomes.

NIHSS scoring domains:

• 1a. Level of consciousness (0-3)
• 1b. LOC questions (0-2)
• 1c. LOC commands (0-2)
• 2. Gaze (0-2)
• 3. Visual fields (0-3)
• 4. Facial palsy (0-3)
• 5. Motor arm (0-4, each arm)
• 6. Motor leg (0-4, each leg)
• 7. Limb ataxia (0-2)
• 8. Sensory (0-2)
• 9. Language/aphasia (0-3)
• 10. Dysarthria (0-2)
• 11. Extinction/inattention (0-2)

NIHSS interpretation:

• 0: No stroke symptoms
• 1-4: Minor stroke
• 5-15: Moderate stroke
• 16-20: Moderate-to-severe stroke
• 21-42: Severe stroke

Prognostic value:

• NIHSS 0-7: 60-70% achieve excellent outcome (mRS 0-1)
• NIHSS 8-14: 35-45% achieve good outcome (mRS 0-2)
• NIHSS ≥15: 20-30% achieve good outcome
• NIHSS greater than 20: below 10% achieve functional independence (mRS 0-2) (PMID: 11157634)

Anterior Circulation Syndromes

Middle cerebral artery (MCA) territory (most common, 60-70% of strokes):

• M1 occlusion: Contralateral hemiparesis (face and arm > leg), hemisensory loss, homonymous hemianopia, gaze preference toward lesion
• Dominant hemisphere: Global aphasia (M1), Broca's aphasia (superior division), Wernicke's aphasia (inferior division)
• Non-dominant hemisphere: Neglect, anosognosia, constructional apraxia

Anterior cerebral artery (ACA) territory (rare, 1-3%):

• Contralateral hemiparesis (leg > arm), urinary incontinence, abulia, grasp reflex, transcortical motor aphasia (if dominant)

Internal carotid artery (ICA) occlusion:

• Variable presentation depending on collateral status (asymptomatic to massive hemispheric infarction)
• May present as MCA + ACA territory infarction, or MCA + ophthalmic artery (ipsilateral monocular blindness)

Posterior Circulation Syndromes

Posterior cerebral artery (PCA) territory (5-10%):

• Homonymous hemianopia (macular sparing if from embolic occlusion), visual agnosia, alexia without agraphia (dominant), prosopagnosia (non-dominant)
• Thalamic infarction: Contralateral hemisensory loss, hemiataxia, thalamic pain syndrome (Déjerine-Roussy)

Basilar artery occlusion (1-4%, but high mortality 70-90%):

• Locked-in syndrome: Quadriplegia, anarthria, preserved consciousness, vertical eye movements
• Coma, bilateral motor deficits, ophthalmoplegia, respiratory failure
• Top-of-basilar syndrome: Bilateral PCA territory, thalamus, midbrain (altered consciousness, vertical gaze palsy, memory impairment)

Vertebral artery / posterior inferior cerebellar artery (PICA) - Lateral medullary (Wallenberg) syndrome:

• Ipsilateral facial pain/sensory loss, Horner's syndrome, ataxia, dysphagia, hoarseness
• Contralateral body pain/sensory loss
• Nystagmus, vertigo, nausea/vomiting

Cerebellar infarction:

• Ipsilateral limb ataxia, dysmetria, dysarthria, vertigo, nausea/vomiting
• Risk of hydrocephalus (4th ventricle compression) and tonsillar herniation (may require suboccipital decompression)

Lacunar Syndromes (Small Vessel Disease)

Lacunar infarcts are small (below 15 mm diameter) subcortical infarcts resulting from lipohyalinosis or microatheroma of penetrating arteries (PMID: 2691839). Account for 20-25% of ischemic strokes.

Classic lacunar syndromes (no cortical signs):

• Pure motor hemiparesis (50%): Posterior limb internal capsule, basis pontis
• Pure sensory stroke (10%): Ventral posterolateral thalamus
• Ataxic hemiparesis (10%): Posterior limb internal capsule, basis pontis
• Sensorimotor stroke (10%): Posterior limb internal capsule, thalamus
• Dysarthria-clumsy hand syndrome (5%): Basis pontis, genu internal capsule

Risk factors: Hypertension (80%), diabetes (30%), smoking, age greater than 60 years

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Investigations

Neuroimaging

Non-contrast CT brain is the first-line investigation, performed immediately upon presentation (PMID: 32758750):

Early CT findings (within 3-6 hours):

• Hyperdense vessel sign (MCA, basilar): Direct visualization of thrombus (sensitivity 30-50%, specificity 90-95%)
• Loss of grey-white matter differentiation (insular ribbon sign, obscuration of lentiform nucleus)
• Sulcal effacement and loss of basal ganglia borders
• ASPECTS (Alberta Stroke Program Early CT Score): 10-point score assessing early ischemic changes in MCA territory; score ≤7 predicts poor outcome, ≤5 is relative contraindication for thrombolysis (PMID: 10716264)

Late CT findings (6-24 hours):

• Hypodense infarct conforming to vascular territory
• Mass effect: Sulcal effacement, midline shift, ventricular compression
• Hemorrhagic transformation: Petechiae (HI-1, HI-2) or frank hematoma (PH-1, PH-2)

CT angiography (CTA): Identifies large vessel occlusion and assesses collateral circulation (PMID: 23204507)

• Sensitivity 95-99%, specificity 98-100% for LVO detection
• Clot burden score (0-10): Quantifies thrombus extent (lower score = greater burden)
• Collateral score (0-3): Predicts penumbra salvageability and treatment response

CT perfusion (CTP): Estimates ischemic core and penumbra using cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and time-to-peak (TTP) maps (PMID: 29129158)

• Core: CBF below 30% of normal, indicating irreversible injury
• Penumbra: MTT or TTP prolonged but CBV maintained (mismatch)
• Infarct growth rate: Baseline core volume vs follow-up infarct volume (mL/h)
• Used to select patients for late-window thrombectomy (6-24h)

MRI brain with diffusion-weighted imaging (DWI):

• Most sensitive for acute ischemia (detects infarction within 30-60 minutes, sensitivity greater than 95%)
• DWI hyperintensity indicates cytotoxic edema
• ADC (apparent diffusion coefficient) map: Reduced diffusion in acute infarction
• Gradient echo (GRE) or susceptibility-weighted imaging (SWI): Detects hemorrhage, microbleeds (bleeding risk stratification)
• FLAIR (fluid-attenuated inversion recovery): DWI-FLAIR mismatch identifies stroke below 4.5h (wake-up stroke assessment)
• MR angiography (MRA): Non-invasive vessel imaging (alternative to CTA)

Stroke Etiology Workup

Cardiac investigations (identify cardioembolic source):

• 12-lead ECG: Atrial fibrillation, ventricular hypertrophy, ischemic changes
• Transthoracic echocardiography (TTE): Valvular disease, mural thrombus, ejection fraction, regional wall motion abnormalities
• Transesophageal echocardiography (TEE) if TTE non-diagnostic: Patent foramen ovale (PFO), atrial septal aneurysm, left atrial appendage thrombus, aortic arch atheroma
• Prolonged cardiac monitoring (30-day event recorder): Detects paroxysmal AF in 16-23% of cryptogenic strokes (PMID: 24744381)

Vascular imaging (extracranial and intracranial):

• Carotid Doppler ultrasound: Degree of stenosis (NASCET criteria), plaque morphology
• CTA or MRA neck and intracranial vessels: Atherosclerosis, dissection, stenosis, occlusion
• Conventional angiography if non-invasive imaging inconclusive (vasculitis, moyamoya)

Laboratory studies:

• Full blood count: Polycythemia, thrombocytosis, leukemia
• Coagulation profile (INR, aPTT): Baseline for thrombolysis, anticoagulation monitoring
• Lipid profile: LDL-C, HDL-C, triglycerides, Lp(a)
• HbA1c, fasting glucose: Diabetes screening
• Renal function, electrolytes: Baseline, guide secondary prevention
• Troponin: Concurrent acute coronary syndrome (occurs in 5-10%)

Thrombophilia screen (if age below 50, recurrent events, family history):

• Antiphospholipid antibodies (lupus anticoagulant, anticardiolipin, anti-β2-glycoprotein-I)
• Factor V Leiden, prothrombin G20210A mutation
• Protein C, protein S, antithrombin deficiency
• Hyperhomocysteinemia

Vasculitis/inflammatory screen (if young, atypical presentation):

• ESR, CRP, ANA, ANCA, complement (C3, C4)
• Syphilis serology, HIV serology

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Acute Management

Time-Critical Assessment ("Code Stroke")

Immediate actions (within 10 minutes of arrival):

1. Activate stroke team (neurology, radiology, ICU)
2. ABCDE assessment: Airway, breathing (SpO₂ greater than 94%), circulation (IV access, BP), disability (GCS, pupils, glucose), exposure
3. Fingerstick glucose: Exclude hypoglycemia (below 3 mmol/L) or severe hyperglycemia (greater than 20 mmol/L) as stroke mimics
4. Vital signs: BP (both arms), heart rate, temperature, SpO₂
5. NIHSS score: Baseline severity
6. Last known well (LKW) time: Critical for reperfusion eligibility
7. Brief history: Stroke symptoms, risk factors, medications (anticoagulants), contraindications to thrombolysis (recent surgery, bleeding history)

Door-to-imaging target: ≤25 minutes

Door-to-needle target (thrombolysis): ≤60 minutes

Door-to-groin puncture target (thrombectomy): ≤90 minutes

Blood Pressure Management

BP is often elevated in acute stroke (60-80% have SBP greater than 140 mmHg) due to stress, pain, urinary retention, or physiological response to maintain cerebral perfusion. Avoid aggressive BP lowering in most cases to preserve penumbral flow (PMID: 31172749).

Permissive hypertension protocol (no thrombolysis given):

• Allow SBP up to 220 mmHg and DBP up to 120 mmHg for first 24-48 hours
• Only treat BP if:
  • SBP greater than 220 mmHg or DBP greater than 120 mmHg on two readings 5-10 minutes apart
  • Evidence of acute end-organ damage (hypertensive encephalopathy, acute coronary syndrome, aortic dissection, acute pulmonary edema)
  • Pre-existing comorbidity requiring urgent BP control (e.g., severe aortic stenosis)

Post-thrombolysis BP targets (PMID: 7477192):

• Pre-lysis: Reduce BP to SBP below 185 mmHg and DBP below 110 mmHg before administering alteplase
• Post-lysis: Maintain SBP below 180 mmHg and DBP below 105 mmHg for 24 hours post-treatment
• If BP exceeds targets despite treatment, hold or discontinue alteplase

Antihypertensive agents for acute lowering:

• Labetalol 10-20 mg IV bolus over 1-2 min, repeat q10-20min up to 300 mg total (avoid if heart failure, bradycardia)
• Nicardipine 5 mg/h IV infusion, titrate by 2.5 mg/h q5-15min to target (max 15 mg/h)
• Hydralazine 10-20 mg IV bolus (slower onset, less predictable, generally not preferred)
• Glyceryl trinitrate (GTN) infusion if acute coronary syndrome or heart failure

Avoid: Nifedipine (short-acting, unpredictable), clonidine (sedation), sublingual agents (difficult to titrate)

Relative contraindications to permissive hypertension:

• Thrombolysis or thrombectomy administered: Follow post-lysis BP targets
• Intracranial hemorrhage on imaging
• Aortic dissection
• Acute myocardial infarction or acute pulmonary edema

Intravenous Thrombolysis

Indications (PMID: 7477192, PMID: 19828521):

• Clinical diagnosis of ischemic stroke with measurable neurological deficit (NIHSS ≥1)
• Symptom onset (or last known well) ≤4.5 hours
• Age ≥18 years
• CT brain excludes intracranial hemorrhage

Alteplase (recombinant tissue plasminogen activator, rtPA) dosing:

• 0.9 mg/kg (maximum 90 mg)
• 10% as IV bolus over 1 minute
• 90% as IV infusion over 60 minutes

Absolute contraindications:

• Intracranial hemorrhage on CT
• Symptom onset greater than 4.5 hours (or unknown/wake-up stroke without DWI-FLAIR mismatch)
• Ischemic stroke within 3 months
• Severe head trauma within 3 months
• Intracranial/intraspinal surgery within 3 months
• History of intracranial hemorrhage
• Uncontrolled hypertension (SBP greater than 185 mmHg or DBP greater than 110 mmHg despite treatment)
• Active bleeding or acute bleeding diathesis (platelets below 100,000, INR greater than 1.7, aPTT greater than 40 sec, therapeutic LMWH within 24h)
• Blood glucose below 2.8 mmol/L
• Suspected aortic dissection
• Suspected endocarditis

Relative contraindications (individualized decision):

• Minor or rapidly improving symptoms (NIHSS below 4)
• Severe stroke (NIHSS greater than 25)
• Seizure at stroke onset with postictal deficits
• Major surgery or serious trauma within 14 days
• GI or GU bleeding within 21 days
• Arterial puncture at non-compressible site within 7 days
• Recent myocardial infarction (within 3 months)
• Pregnancy
• Oral anticoagulation (warfarin with INR ≤1.7 may be acceptable, DOACs within 48h contraindication)
• Age greater than 80 years combined with NIHSS greater than 25, diabetes, or prior stroke

ECASS-3 criteria (3-4.5 hour window) exclude patients with:

• Age greater than 80 years
• NIHSS greater than 25
• Combination of prior stroke AND diabetes
• Oral anticoagulation (any INR)

Efficacy (PMID: 27115388, meta-analysis of 9 trials, 6,756 patients):

• NNT = 7-10 for excellent outcome (mRS 0-1) at 3 months
• OR 1.75 (95% CI 1.35-2.27) for functional independence if treated below 3 hours
• OR 1.26 (95% CI 1.05-1.51) for functional independence if treated 3-4.5 hours
• Benefit diminishes with time; every 15-minute delay reduces probability of good outcome by 4%

Symptomatic intracranial hemorrhage (sICH):

• Occurs in 6-7% (vs 1-2% placebo)
• Defined as any hemorrhage with ≥4-point NIHSS worsening within 36 hours
• Higher risk with: Age greater than 75, NIHSS greater than 20, hyperglycemia, ASPECTS ≤7, leukoaraiosis

Post-thrombolysis monitoring:

• Neuro observations q15min for 2h, then q30min for 6h, then q1h for 16h
• Blood pressure q15min for 2h, then q30min for 6h, maintain SBP below 180/105 mmHg
• Avoid antiplatelet or anticoagulation for 24 hours post-thrombolysis
• Repeat CT brain at 24 hours or immediately if neurological deterioration, severe headache, nausea/vomiting, hypertension

Endovascular Thrombectomy

Indications (PMID: 25622020, PMID: 29129157, PMID: 29129158):

• Large vessel occlusion confirmed on CTA/MRA:
  • Internal carotid artery (ICA)
  • M1 segment of middle cerebral artery
  • Proximal M2 segment (dominant branch)
  • Basilar artery (in selected cases)
• Premorbid functional independence (mRS 0-1)
• ASPECTS ≥6 (or small core on CT perfusion)
• NIHSS ≥6 (generally; lower scores acceptable for basilar occlusion)
• Age ≥18 years

Time windows:

• 0-6 hours: CTA alone sufficient to demonstrate LVO (PMID: 25622020)
• 6-16 hours: Perfusion imaging (CTP or MRI) required to demonstrate salvageable penumbra (core below 70 mL, mismatch ratio ≥1.8) (PMID: 29129157)
• 16-24 hours: Highly selected cases with favorable imaging (DAWN/DEFUSE-3 criteria) (PMID: 29129158)

DAWN trial criteria (wake-up or late presentation 6-24h):

• Age ≥80, NIHSS ≥10, core below 21 mL, OR
• Age below 80, NIHSS ≥10, core below 31 mL, OR
• Age below 80, NIHSS ≥20, core below 51 mL

DEFUSE-3 criteria (6-16h window):

• Core below 70 mL, mismatch volume ≥15 mL, mismatch ratio ≥1.8

Thrombectomy techniques:

• Stent retriever (Solitaire, Trevo): Deploy across thrombus, allow integration, retrieve with aspiration
• Contact aspiration (ADAPT technique): Direct aspiration through large-bore catheter
• Combination approach: Stent retriever + balloon guide catheter + aspiration

Outcomes (PMID: 26786802, meta-analysis of 5 trials, 1,287 patients):

• NNT = 3-7 for functional independence (mRS 0-2) at 90 days
• OR 2.49 (95% CI 1.76-3.53) for good outcome vs medical therapy alone
• Number needed to treat to prevent one case of disability or death = 3
• Benefit maintained across subgroups (age, NIHSS, ASPECTS, IV tPA status)

Complications:

• Symptomatic ICH: 4-6%
• Subarachnoid hemorrhage: 3-5% (vessel perforation)
• Distal embolization: 5-10%
• Arterial dissection or perforation: 1-2%
• Groin hematoma or pseudoaneurysm: 2-4%

Bridging thrombolysis: Patients eligible for both IV alteplase and thrombectomy should receive both treatments without delay to thrombectomy (door-to-needle first, then proceed to angio suite) (PMID: 34111968).

Airway and Ventilation

Indications for intubation (PMID: 22821541):

• GCS ≤8 or rapidly declining consciousness
• Loss of protective airway reflexes (cough, gag)
• Inability to maintain oxygenation (SpO₂ below 90% despite supplemental O₂)
• Severe respiratory distress (RR greater than 35, accessory muscle use)
• Need for airway protection during transfer or procedures
• To facilitate hyperventilation for acute ICP crisis (temporizing measure)

Avoid hyperventilation except as temporary measure for impending herniation; target normocapnia (PaCO₂ 35-45 mmHg). Hypocapnia causes cerebral vasoconstriction, reducing CBF and potentially worsening ischemia (PMID: 22821541).

Oxygenation target: SpO₂ 94-98%. Avoid both hypoxia (SpO₂ below 90%, worsens ischemia) and hyperoxia (PaO₂ greater than 300 mmHg, may increase oxidative stress) (PMID: 28270466).

Pre-intubation considerations:

• Aspiration risk (dysphagia present in 40-70% of acute stroke)
• Hemodynamic instability during induction (consider reduced-dose sedation, vasopressor readiness)
• Raised ICP risk (smooth induction, avoid coughing/bucking, lignocaine pre-treatment)
• Cervical spine assessment if trauma or dissection suspected

Glucose Management

Both hypoglycemia and hyperglycemia worsen ischemic brain injury.

Target glucose: 6-10 mmol/L (PMID: 28082686)

Hyperglycemia (glucose greater than 10 mmol/L) present in 30-40% of acute strokes; associated with:

• Increased hemorrhagic transformation risk (OR 1.7-3.0)
• Larger final infarct volume
• Worse functional outcome (OR 1.3-2.3 for poor outcome per 1 mmol/L increase)

Hypoglycemia (below 3 mmol/L) is a stroke mimic and must be corrected immediately (50 mL 50% dextrose IV).

Insulin infusion if persistent hyperglycemia (glucose greater than 10 mmol/L on two readings or greater than 15 mmol/L):

• Start at 1-2 units/h, titrate q1-2h to target
• Monitor glucose q1-2h initially, then q4h when stable
• Avoid rapid glucose reduction (risk of cerebral edema)

Temperature Management

Fever (greater than 37.5°C) occurs in 40-50% of stroke patients within 48 hours and is associated with worse outcomes (OR 1.3 per 1°C increase) (PMID: 11859158).

Target normothermia: Core temperature below 37.5°C

Antipyretics:

• Paracetamol 1g IV/PO q6h (safe, first-line)
• Surface or intravascular cooling if refractory (cooling blanket, Arctic Sun, Thermogard)

Avoid hypothermia (below 36°C): No proven benefit in ischemic stroke, may cause shivering, arrhythmias, coagulopathy.

Identify and treat fever source: Aspiration pneumonia, urinary tract infection, central fever (hypothalamic involvement).

Antithrombotic Therapy

Antiplatelet therapy (not given thrombolysis):

• Aspirin 300 mg PO/PR/NG within 48 hours of symptom onset (PMID: 10770981)
• Continue aspirin 75-150 mg daily long-term
• Delay aspirin for 24 hours if thrombolysis given

Dual antiplatelet therapy (DAPT) for minor stroke or high-risk TIA (NIHSS ≤3, ABCD² ≥4):

• Aspirin 300 mg loading + clopidogrel 300 mg loading within 24 hours
• Continue aspirin 75 mg + clopidogrel 75 mg for 21 days, then aspirin monotherapy (PMID: 23803136, PMID: 29766750)
• Reduces recurrent stroke by 30% at 90 days (NNT = 30) but increases bleeding risk if moderate-severe stroke

Anticoagulation for atrial fibrillation:

• Delay anticoagulation to reduce hemorrhagic transformation risk:
  • "Small stroke (NIHSS below 5): Start at 1-3 days"
  • "Moderate stroke (NIHSS 5-15): Start at 3-6 days"
  • "Large stroke (NIHSS greater than 15): Start at 12-14 days (individualized, may require imaging follow-up)"
• Direct oral anticoagulants (DOACs) preferred over warfarin (lower ICH risk, no monitoring) (PMID: 28399849)
• Options: Apixaban 5 mg BD, rivaroxaban 20 mg daily, dabigatran 150 mg BD, edoxaban 60 mg daily

Deep vein thrombosis (DVT) prophylaxis:

• Intermittent pneumatic compression (IPC) devices from admission (PMID: 23281560)
• Low-molecular-weight heparin (LMWH) enoxaparin 40 mg SC daily if immobile and no hemorrhagic transformation
• Avoid LMWH for 24 hours post-thrombolysis

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Intensive Care Management

ICP Monitoring and Management

Indications for ICP monitoring (PMID: 19246704):

• Large hemispheric infarction (greater than 50% MCA territory, ASPECTS ≤5)
• Clinical deterioration with decreased GCS
• Massive cerebellar infarction with obstructive hydrocephalus
• Post-decompressive craniectomy

ICP monitoring modalities:

• External ventricular drain (EVD): Gold standard, allows CSF drainage (therapeutic), accurate ICP measurement
• Intraparenchymal monitor (Codman, Camino): Less invasive, no CSF drainage capability

Target ICP: below 20 mmHg

Cerebral perfusion pressure (CPP) = MAP - ICP; target 60-70 mmHg

ICP management tiers (PMID: 19246704):

Tier 1 (first-line):

• Head-of-bed elevation 30°: Improves venous drainage
• Midline head position: Avoid jugular venous compression
• Sedation and analgesia: Propofol or midazolam, fentanyl
• Avoid hyperthermia: Target below 37.5°C
• Normoglycemia: 6-10 mmol/L
• Normocapnia: PaCO₂ 35-45 mmHg (avoid routine hyperventilation)
• Maintain MAP to achieve CPP 60-70 mmHg (vasopressors if needed)

Tier 2 (refractory ICP greater than 20 mmHg):

• Osmotic therapy:
  • Mannitol 0.25-1 g/kg IV bolus q4-6h (target serum osmolality below 320 mOsm/kg)
  • "Hypertonic saline 3% NaCl 150-250 mL bolus over 15-30 min (or 23.4% NaCl 30 mL central line bolus) (PMID: 25891960)"
  • Monitor serum sodium (avoid greater than 160 mmol/L), serum osmolality (below 320 mOsm/kg)
• Hyperventilation (temporizing only): Target PaCO₂ 30-35 mmHg for up to 1 hour during herniation crisis
• EVD CSF drainage (if not already in situ)

Tier 3 (malignant ICP, impending herniation):

• Decompressive craniectomy (see below)
• Barbiturate coma (pentobarbital 10 mg/kg loading over 30 min, then 5 mg/kg/h for 3h, then 1 mg/kg/h; requires continuous EEG monitoring, hemodynamic support)
• Induced hypothermia (experimental, 32-35°C; increases infection, coagulopathy, no clear benefit)

Decompressive Craniectomy

Indications (PMID: 17321735, PMID: 18258826):

• Malignant MCA syndrome: Large hemispheric infarction (greater than 50% MCA territory) with progressive decline in GCS, uncontrolled ICP, or clinical herniation
• Age ≤60 years (primary trials; benefit in older patients debated)
• Within 48 hours of symptom onset (ideally before GCS drops to ≤8)
• Massive cerebellar infarction with brainstem compression, obstructive hydrocephalus, or clinical deterioration

Surgical technique:

• Hemicraniectomy: Large fronto-temporo-parietal bone flap (≥12 cm diameter) with duraplasty
• Suboccipital decompression for cerebellar infarction with or without EVD

Outcomes (PMID: 17321735, DECIMAL, DESTINY, HAMLET pooled analysis, n=93):

• Mortality reduction: 78% medical vs 29% surgical (ARR 49%, NNT = 2)
• Functional outcome: 43% achieve mRS 0-3 (moderate disability or better) vs 21% medical (NNT = 5)
• 75% survive with mRS ≤4 (moderate disability, able to walk) vs 24% medical
• Quality of life: Majority of survivors (70-80%) rate quality of life as acceptable, do not regret surgery

Age greater than 60 years: DESTINY-II trial (PMID: 24587114) showed mortality reduction (33% vs 70%) but higher proportion with severe disability (mRS 5 = 32%); individualized decision with patient/family values.

Timing: Earlier surgery (below 24h) associated with better outcomes than delayed (greater than 48h). Operate before fixed pupil dilation or GCS ≤6.

Complications

Hemorrhagic transformation:

• Monitor with repeat CT brain at 24h post-lysis or immediately if neurological deterioration
• Symptomatic ICH: Discontinue anticoagulation, reverse if applicable (prothrombin complex concentrate for warfarin, idarucizumab for dabigatran, andexanet alfa for apixaban/rivaroxaban), neurosurgical consult
• Consider platelet transfusion if recent antiplatelet therapy and significant hemorrhage

Seizures:

• Occur in 5-10% of ischemic strokes (higher in cortical, hemorrhagic transformation)
• Acute seizure: Lorazepam 4 mg IV or levetiracetam 1,000-1,500 mg IV
• Prophylactic antiepileptics not recommended unless seizure witnessed
• If recurrent seizures, start maintenance antiepileptic (levetiracetam 500 mg BD, phenytoin 300 mg daily, valproate 600-1,200 mg daily)

Aspiration pneumonia:

• Occurs in 10-25% of acute strokes (dysphagia in 40-70%)
• Nil-by-mouth until swallow assessment (speech pathology, water swallow test, fiberoptic endoscopic evaluation)
• Aspiration precautions: Head-of-bed elevation 30-45°, oral care
• Treat pneumonia with antibiotics (co-amoxiclav, ceftriaxone + metronidazole)

Venous thromboembolism (VTE):

• DVT occurs in 10-20%, PE in 1-2% without prophylaxis
• IPC devices from admission (reduce DVT by 50%)
• LMWH (enoxaparin 40 mg SC daily) if immobile, no hemorrhagic transformation, ≥24h post-thrombolysis
• Early mobilization when safe

Neurogenic cardiac complications:

• Troponin elevation in 5-20% (demand ischemia, catecholamine surge, Takotsubo cardiomyopathy)
• ECG abnormalities: T-wave inversion, QT prolongation, ST-segment changes
• Arrhythmias: Atrial fibrillation (may be cause or consequence), ventricular ectopy
• Treat symptomatic arrhythmias, optimize cardiac function

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Secondary Prevention

Risk Factor Modification

Blood pressure control (chronic phase, after acute period):

• Target below 130/80 mmHg (PMID: 30575490)
• Start or resume antihypertensives after acute period (typically day 1-7 depending on BP)
• ACE inhibitor or ARB preferred (perindopril, ramipril, candesartan) - reduce recurrent stroke by 25-30% (PMID: 11566974)
• Add thiazide diuretic (indapamide) or calcium channel blocker (amlodipine) if target not met

Lipid management:

• Target LDL-C below 1.8 mmol/L (PMID: 30611806)
• High-intensity statin: Atorvastatin 80 mg daily or rosuvastatin 20-40 mg daily
• Reduces recurrent stroke by 15-20% (NNT = 50-70 for 5 years)
• Add ezetimibe 10 mg if LDL-C remains greater than 1.8 mmol/L on maximal statin

Diabetes management:

• Target HbA1c below 7% (below 53 mmol/mol)
• Metformin first-line, consider SGLT2 inhibitor or GLP-1 agonist (cardiovascular benefits)

Smoking cessation:

• Reduces stroke recurrence by 30-40%
• Nicotine replacement, varenicline, or bupropion; counseling and support programs

Lifestyle modifications:

• Mediterranean diet (vegetables, fruits, whole grains, fish, olive oil)
• Physical activity 30-60 minutes moderate-intensity 5-7 days/week
• Weight reduction if BMI greater than 25 kg/m² (target BMI 18.5-24.9)
• Limit alcohol to ≤2 standard drinks/day

Carotid Stenosis Management

Symptomatic carotid stenosis (stroke/TIA in ipsilateral carotid territory):

• 70-99% stenosis: Carotid endarterectomy (CEA) or stenting (CAS) within 2 weeks of event (PMID: 15166063)
  • CEA reduces recurrent stroke by 50% at 5 years (ARR 16%, NNT = 6)
  • Surgery within 2 weeks superior to delayed (4.6% vs 11.8% 6-month stroke risk)
• 50-69% stenosis: CEA beneficial in selected patients (men, age below 75, recent symptoms, no significant comorbidity)
• below 50% stenosis: Medical management alone

Asymptomatic carotid stenosis:

• 60-99% stenosis: CEA considered if perioperative stroke/death risk below 3%, life expectancy greater than 5 years, annual stroke risk 1-2% (PMID: 10439992)
• Medical management improving outcomes; surgery benefit marginal in modern era (NNT = 50-100 for 5 years)

Atrial Fibrillation Anticoagulation

CHA₂DS₂-VASc score (risk stratification for AF stroke risk):

• C = Congestive heart failure (1 point)
• H = Hypertension (1 point)
• A₂ = Age ≥75 years (2 points)
• D = Diabetes (1 point)
• S₂ = Prior Stroke/TIA/thromboembolism (2 points)
• V = Vascular disease (1 point)
• A = Age 65-74 years (1 point)
• Sc = Sex category (female 1 point)

Score ≥2 (men) or ≥3 (women): Anticoagulation recommended

Direct oral anticoagulants (DOACs) preferred over warfarin (PMID: 28399849):

• Apixaban 5 mg BD (2.5 mg BD if ≥2 of: age ≥80, weight ≤60 kg, creatinine ≥133 μmol/L)
• Rivaroxaban 20 mg daily (15 mg if CrCl 30-49)
• Dabigatran 150 mg BD (110 mg BD if age ≥80 or high bleeding risk)
• Edoxaban 60 mg daily (30 mg if weight ≤60 kg, CrCl 30-50, or P-glycoprotein inhibitors)

Warfarin if DOAC contraindicated (mechanical valve, severe renal impairment CrCl below 30):

• Target INR 2-3
• Monitor INR weekly until stable, then monthly

Timing: See "Acute Management" section for timing post-stroke.

Patent Foramen Ovale (PFO) Closure

PFO present in 25% of general population; found in 40-50% of cryptogenic strokes in patients below 60 years.

Indications for PFO closure (PMID: 29766761, PMID: 28902590):

• Age below 60 years
• Cryptogenic stroke (no other etiology after comprehensive workup)
• Moderate-large PFO with substantial shunt
• Preferably with atrial septal aneurysm (increases risk)

Closure vs medical therapy: Reduces recurrent stroke by 40-60% (ARR 3-4% over 5 years, NNT = 25-30) (PMID: 29766761).

Procedure: Percutaneous transcatheter closure (Amplatzer, Gore Cardioform, etc.) with post-procedure antiplatelet therapy (aspirin 75-100 mg + clopidogrel 75 mg for 3-6 months).

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Prognosis

Functional Outcome

Modified Rankin Scale (mRS) is the standard outcome measure:

• mRS 0: No symptoms
• mRS 1: No significant disability (able to carry out all usual activities)
• mRS 2: Slight disability (unable to carry out all previous activities but able to look after own affairs)
• mRS 3: Moderate disability (requires some help but able to walk unassisted)
• mRS 4: Moderately severe disability (unable to walk or attend to bodily needs without assistance)
• mRS 5: Severe disability (bedridden, incontinent, requires constant care)
• mRS 6: Dead

Overall outcomes at 3 months (PMID: 29129157):

• 30-40% achieve excellent outcome (mRS 0-1)
• 50-60% achieve functional independence (mRS 0-2)
• 70-75% survive (mRS 0-5)
• 25-30% mortality

Prognostic factors:

Poor outcome predictors:

• Age greater than 80 years: 2-3× higher mortality, 40-50% lower probability of mRS 0-2
• NIHSS greater than 15: below 30% achieve mRS 0-2
• ASPECTS ≤5: Large baseline infarct, 70-80% poor outcome
• Hemorrhagic transformation: 40-60% mortality for symptomatic ICH
• Atrial fibrillation: 1.5-2× higher mortality, worse functional outcome
• Pre-stroke disability (mRS ≥2): Unlikely to improve beyond baseline
• Hyperglycemia (admission glucose greater than 10 mmol/L): 1.3-1.5× worse outcome
• Fever: Each 1°C increase associated with 1.3× worse outcome

Favorable outcome predictors:

• Young age (below 60 years): 60-70% achieve mRS 0-2
• Low NIHSS (below 5): 70-80% achieve mRS 0-1
• Small infarct volume
• Good collaterals (collateral score 2-3)
• Early reperfusion (below 3 hours)
• Lacunar stroke subtype: 60-70% good outcome

Recurrence Risk

Early recurrence (first 90 days): 5-10%

• Highest in first 7 days (1-2% per day)
• Cardioembolic subtype highest risk (10-15% at 90 days)

Annual recurrence rate: 3-5% per year with optimal secondary prevention

Cumulative recurrence:

• 1 year: 8-12%
• 5 years: 20-30%
• 10 years: 30-40%

Risk stratification (ABCD² score for TIA/minor stroke):

• A = Age ≥60 (1 point)
• B = BP ≥140/90 (1 point)
• C = Clinical features: unilateral weakness (2 points), speech disturbance without weakness (1 point)
• D = Duration: ≥60 min (2 points), 10-59 min (1 point)
• D = Diabetes (1 point)

ABCD² score interpretation:

• 0-3: Low risk (1% 2-day stroke risk)
• 4-5: Moderate risk (4% 2-day stroke risk)
• 6-7: High risk (8% 2-day stroke risk)

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Special Populations

Posterior Circulation (Basilar Artery) Stroke

Clinical features: Altered consciousness, quadriparesis, locked-in syndrome, cranial nerve deficits, ataxia, bilateral visual field defects.

Mortality: 70-90% with medical management alone for basilar occlusion.

Thrombolysis: May be considered up to 6-12 hours or longer (extended window due to brainstem tolerance to ischemia and poor alternative options) (PMID: 30071988).

Thrombectomy: BEST trial (PMID: 37990444) showed no significant benefit of thrombectomy over medical therapy in unselected basilar occlusion patients (mRS 0-3: 42% thrombectomy vs 32% medical, p=0.14), but BASICS trial (PMID: 37990442) suggested benefit in selected patients with good collaterals and limited infarct.

Current practice: Individualized decision based on imaging (pc-ASPECTS, collateral status, time from onset), patient age, and baseline function. Thrombectomy considered if:

• Presentation within 6-12 hours
• pc-ASPECTS ≥8
• Absence of extensive brainstem infarction
• Premorbid mRS 0-2

Wake-Up Stroke

Definition: Stroke symptoms discovered upon awakening, time of onset unknown (last known well = bedtime).

Accounts for 20-25% of ischemic strokes (PMID: 30811911).

Imaging-based selection:

• DWI-FLAIR mismatch (DWI hyperintense, FLAIR negative) indicates stroke below 4.5 hours, eligible for thrombolysis (PMID: 30811911)
• CT perfusion mismatch (core below 70 mL, mismatch ratio ≥1.8) eligible for thrombectomy (DAWN/DEFUSE-3 criteria)

WAKE-UP trial (PMID: 30811911, n=503): MRI-guided thrombolysis in DWI-FLAIR mismatch patients resulted in better outcomes (mRS 0-1: 53% vs 42%, NNT = 9).

Young Stroke (below 50 Years)

Accounts for 10-15% of ischemic strokes; distinct etiologies require targeted investigation (PMID: 27899503):

Etiologies:

• Arterial dissection (10-25%): Carotid or vertebral, often traumatic or spontaneous
• Paradoxical embolism via PFO (10-20%)
• Hypercoagulable states (5-10%): Antiphospholipid syndrome, Factor V Leiden, prothrombin mutation, protein C/S deficiency
• Vasculitis (1-3%): Primary CNS vasculitis, Takayasu, SLE
• Drug-related (cocaine, amphetamines, cannabis)
• Moyamoya disease
• CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy)
• Mitochondrial disorders (MELAS)

Workup additions:

• Echocardiography (TEE to assess PFO, atrial septal aneurysm, aortic arch atheroma)
• Extended thrombophilia screen
• Vasculitis screen (ESR, CRP, ANA, ANCA, complement)
• Toxicology screen
• Genetic testing if family history or suggestive imaging (CADASIL, Fabry disease)

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SAQ Practice Questions

SAQ 1: Thrombolysis Eligibility and Management

Question: A 68-year-old man presents to the Emergency Department at 09:15 with sudden-onset right-sided weakness and aphasia. His wife reports he was last seen normal at 07:00 when she left for work. On examination, GCS 14 (E4V4M6), right hemiparesis (power 2/5 arm, 3/5 leg), expressive aphasia, NIHSS 16. BP 192/104 mmHg, HR 88 bpm irregular, glucose 8.2 mmol/L. CT brain shows hyperdense left MCA sign, ASPECTS 8, no hemorrhage. Past medical history: atrial fibrillation (not anticoagulated), hypertension, previous appendectomy 6 months ago.

(a) Is this patient eligible for IV thrombolysis? Justify your answer. (4 marks)

(b) What blood pressure target must be achieved before administering thrombolysis, and what agents would you use? (3 marks)

(c) Describe the alteplase dosing regimen. (2 marks)

(d) Outline your post-thrombolysis monitoring plan. (3 marks)

(e) When would you commence anticoagulation for his atrial fibrillation? (2 marks)

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Model Answer:

(a) Thrombolysis eligibility (4 marks):

YES, eligible (1 mark)

• Time window: Symptom onset (or last known well) 07:00, presentation 09:15 = 2 hours 15 minutes (within 4.5h window) (1 mark)
• Clinical diagnosis of acute ischemic stroke with measurable deficit (NIHSS 16) (0.5 marks)
• CT brain excludes intracranial hemorrhage (0.5 marks)
• Relative contraindications to consider: Surgery (appendectomy) was 6 months ago (guideline contraindication is below 14 days, so acceptable), age 68 years acceptable, NIHSS 16 is moderate-severe but not extreme (greater than 25 relative contraindication) (1 mark)
• Atrial fibrillation: Patient not on anticoagulation, so no INR/DOAC concerns (0.5 marks)

Examiner's note: Must identify time window and absence of absolute contraindications. Bonus for discussing relative contraindications.

(b) Blood pressure target and agents (3 marks):

Target: SBP <185 mmHg and DBP <110 mmHg before administering thrombolysis (1 mark)

Current BP: 192/104 mmHg (above target for SBP, DBP acceptable)

Agents (2 marks, 1 mark per agent with dose):

• Labetalol 10-20 mg IV bolus over 1-2 minutes, repeat q10-20min PRN up to 300 mg total (or 10-20 mg initial, then infusion 2-8 mg/min)
• Nicardipine infusion 5 mg/h IV, titrate by 2.5 mg/h q5-15min to target (max 15 mg/h)
• Alternative: Hydralazine 10-20 mg IV (less preferred due to slower onset, less predictable)

Examiner's note: Must state specific BP targets. Labetalol or nicardipine are preferred agents; candidates should provide doses.

(c) Alteplase dosing (2 marks):

• Total dose: 0.9 mg/kg (maximum 90 mg) (1 mark)
• 10% as IV bolus over 1 minute (0.5 marks)
• 90% as IV infusion over 60 minutes (0.5 marks)

Example: 68 kg patient = 61.2 mg total; 6.1 mg bolus, 55.1 mg infusion over 60 min

Examiner's note: Must state 0.9 mg/kg dosing and split (10% bolus, 90% infusion). Specific patient calculation earns bonus credit.

(d) Post-thrombolysis monitoring (3 marks):

Neurological observations (1 mark):

• q15min for 2 hours, then q30min for 6 hours, then q1h for 16 hours (total 24h monitoring)
• Assess NIHSS, GCS, pupil reactivity, focal deficits

Blood pressure monitoring (1 mark):

• q15min for 2 hours, then q30min for 6 hours
• Target: Maintain SBP <180 mmHg and DBP <105 mmHg for 24 hours post-lysis

Imaging and medication restrictions (1 mark):

• Repeat CT brain at 24 hours post-thrombolysis (or immediately if neurological deterioration, severe headache, nausea/vomiting, hypertension)
• No antiplatelet or anticoagulation for 24 hours post-thrombolysis
• Monitor for signs of hemorrhagic transformation (headache, decline in GCS, new deficits)

Examiner's note: Timing and frequency of neuro/BP obs are key. Must mention 24h imaging and medication restrictions.

(e) Anticoagulation timing (2 marks):

Given moderate stroke (NIHSS 16), anticoagulation for atrial fibrillation should be delayed to 3-6 days post-stroke to minimize hemorrhagic transformation risk (2 marks).

Ideally:

• Repeat imaging at 24-48h to exclude hemorrhagic transformation
• If imaging clear, commence DOAC (e.g., apixaban 5 mg BD, rivaroxaban 20 mg daily) at day 3-6
• Consider earlier (day 3) if small infarct on imaging, or later (day 6-7) if concerns for large infarct or edema

Examiner's note: Must state 3-6 day window and rationale (hemorrhagic transformation risk). 1 mark for timing, 1 mark for rationale.

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SAQ 2: Malignant MCA Syndrome and Decompressive Craniectomy

Question: A 52-year-old woman was admitted 36 hours ago with a large left MCA territory stroke (NIHSS 22, ASPECTS 4). She received IV alteplase at 4 hours but thrombectomy was not performed (M2 occlusion, unfavorable imaging). Over the past 6 hours, she has become progressively drowsy. Current GCS 11 (E3V3M5), right hemiplegia, right pupil 5 mm sluggish. Repeat CT brain shows extensive left hemispheric edema with 8 mm midline shift.

(a) What is this syndrome called, and what are the diagnostic features? (3 marks)

(b) Outline your immediate medical management of raised ICP (Tier 1 and Tier 2 measures). (5 marks)

(c) What are the indications for decompressive craniectomy in this patient? (3 marks)

(d) Describe the evidence for decompressive craniectomy and expected outcomes. (4 marks)

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Model Answer:

(a) Syndrome and diagnostic features (3 marks):

Syndrome: Malignant MCA syndrome (or malignant hemispheric infarction) (1 mark)

Diagnostic features (2 marks):

• Large hemispheric infarction involving greater than 50% of MCA territory (ASPECTS ≤5) (0.5 marks)
• Progressive neurological deterioration within 24-48 hours due to cerebral edema and mass effect (0.5 marks)
• Clinical signs: Declining GCS, signs of herniation (pupillary dilation, decerebrate posturing), progressive hemiplegia (0.5 marks)
• Imaging: Midline shift (greater than 5 mm), compression of basal cisterns, ventricular effacement, uncal herniation (0.5 marks)

Examiner's note: Must identify the syndrome and at least two diagnostic features (clinical deterioration + imaging findings).

(b) Immediate medical ICP management (5 marks):

Tier 1 measures (2.5 marks):

• Head-of-bed elevation 30°, midline head position (avoid jugular compression) (0.5 marks)
• Sedation and analgesia: Propofol infusion (or midazolam) + fentanyl to reduce metabolic demand, avoid agitation (0.5 marks)
• Normothermia: Target temperature below 37.5°C (paracetamol 1g IV q6h, cooling devices if needed) (0.5 marks)
• Normoglycemia: Target glucose 6-10 mmol/L (insulin infusion if hyperglycemic) (0.5 marks)
• Normocapnia: Avoid routine hyperventilation; target PaCO₂ 35-45 mmHg (if intubated) (0.5 marks)

Tier 2 measures (refractory ICP) (2.5 marks):

• Osmotic therapy (1.5 marks):
  • "Hypertonic saline: 3% NaCl 150-250 mL IV bolus over 15-30 min (or 23.4% NaCl 30 mL central line bolus) (preferred in post-thrombolysis setting due to no diuretic effect)"
  • "OR Mannitol: 0.25-1 g/kg IV bolus q4-6h (caution: diuresis may worsen hypotension; monitor serum osmolality below 320 mOsm/kg, Na below 160 mmol/L)"
• Hyperventilation (temporizing): Target PaCO₂ 30-35 mmHg for up to 1 hour during acute herniation crisis (avoid prolonged use due to cerebral vasoconstriction worsening ischemia) (0.5 marks)
• EVD CSF drainage if external ventricular drain in situ (0.5 marks)

Examiner's note: Tier 1 basics (HOB elevation, sedation, normothermia, glucose, ventilation) = 2.5 marks. Tier 2 (osmotic therapy, hyperventilation) = 2.5 marks. Hypertonic saline preferred over mannitol post-lysis.

(c) Indications for decompressive craniectomy (3 marks):

This patient meets criteria (1 mark for stating indication):

1. Large hemispheric infarction (greater than 50% MCA territory, ASPECTS 4) with progressive neurological deterioration (GCS decline 14→11) (1 mark)
2. Age ≤60 years (patient is 52 years old; primary trial evidence strongest in age below 60) (0.5 marks)
3. Clinical signs of herniation (pupillary changes - right pupil 5 mm sluggish, declining GCS) (0.5 marks)
4. Imaging evidence of mass effect (8 mm midline shift) (0.5 marks)
5. Timing within 48 hours (patient 36 hours post-stroke, ideally operate before GCS ≤8 or fixed pupil) (0.5 marks)

Surgical technique: Large fronto-temporo-parietal hemicraniectomy (≥12 cm diameter) with duraplasty

Examiner's note: Must identify age, large infarct, deterioration, and timing as key indications. Bonus for mentioning surgical window.

(d) Evidence and outcomes (4 marks):

Evidence (2 marks):

• Pooled analysis (DECIMAL, DESTINY, HAMLET trials, n=93 patients age below 60) (1 mark)
• Randomized controlled trials comparing decompressive craniectomy to medical management for malignant MCA syndrome within 48h (1 mark)

Outcomes (2 marks):

• Mortality reduction: 78% (medical) vs 29% (surgical); ARR 49%, NNT = 2 (1 mark)
• Functional outcome: 43% achieve mRS 0-3 (moderate disability or better, functional independence) vs 21% medical; 75% achieve mRS ≤4 (able to walk with assistance) vs 24% medical (1 mark)
• Quality of life: Majority of survivors (70-80%) rate quality of life as acceptable and do not regret surgery (bonus 0.5 marks)

Age greater than 60 years (DESTINY-II trial): Mortality reduction (33% vs 70%) but higher severe disability (mRS 5 = 32%); individualized decision considering patient/family values (bonus 0.5 marks)

Examiner's note: Must cite trial evidence (DECIMAL/DESTINY/HAMLET pooled data) and quantify mortality/functional outcome benefit. NNT = 2 for life-saving, NNT = 5 for good outcome.

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Viva Practice Scenarios

Viva 1: Acute Stroke Thrombolysis Decision-Making

Scenario: You are the ICU consultant on call. The Emergency Department refers a 76-year-old man who presented at 14:30 with sudden-onset left-sided weakness and slurred speech. Last known well at 11:00 today (wife witnessed symptom onset). On examination: GCS 15, left hemiparesis (power 3/5 arm and leg), left facial droop, dysarthria, NIHSS 8. BP 210/115 mmHg, HR 76 bpm regular, glucose 6.8 mmol/L. Past history: hypertension (on amlodipine, perindopril), previous ischemic stroke 5 years ago (mRS 1), inguinal hernia repair 10 days ago. CT brain: no hemorrhage, hyperdense right MCA sign, ASPECTS 9.

Questions:

1. Is this patient eligible for IV thrombolysis? What are the key considerations?
2. How would you manage his blood pressure?
3. What are the risks and benefits of thrombolysis in this patient?
4. Would you recommend CT angiography and thrombectomy assessment?
5. If the patient's wife reports he takes aspirin 100 mg daily and clopidogrel 75 mg daily (recent stent), does this change your decision?

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Model Answer:

1. Thrombolysis eligibility:

Time window: Symptom onset 11:00, current time 14:30 = 3.5 hours (within 4.5h window) ✓

Clinical criteria: Acute ischemic stroke, measurable deficit (NIHSS 8 = moderate stroke) ✓

Imaging: CT excludes hemorrhage, ASPECTS 9 (favorable, ≥6 acceptable) ✓

Contraindications:

• Absolute: None identified (no ICH, no recent ICH history, no active bleeding)
• Relative contraindications:
  • "Inguinal hernia repair 10 days ago: Guideline states major surgery within 14 days is a relative contraindication. This patient is at day 10 (borderline). Inguinal hernia repair is minimally invasive, low bleeding risk (vs laparotomy, neurosurgery). Individualized decision: I would discuss with surgical team regarding operative technique (open vs laparoscopic), any bleeding concerns, and bleeding risk assessment. If uncomplicated, I would favor thrombolysis given moderate stroke severity and time window."
  • "Age 76: Not a contraindication; ECASS-3 excluded age greater than 80 combined with NIHSS greater than 25 or diabetes + prior stroke, but this patient has NIHSS 8 and no diabetes."
  • "Severe hypertension (BP 210/115): Must be lowered to SBP below 185/110 before thrombolysis (see question 2)."

Decision: Eligible for thrombolysis after BP control, provided surgical team agrees hernia repair is low risk.

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2. Blood pressure management:

Target: SBP <185 mmHg and DBP <110 mmHg before thrombolysis

Current BP: 210/115 mmHg (both SBP and DBP above target)

Approach:

• Labetalol 10-20 mg IV bolus over 1-2 min, reassess BP at 5-10 min
• If inadequate response, repeat labetalol 10-20 mg q10-20min up to 300 mg total, OR
• Start nicardipine infusion 5 mg/h IV, titrate by 2.5 mg/h q5-15min to target (max 15 mg/h)
• Recheck BP q5-10min during titration
• Once BP controlled (below 185/110), proceed with thrombolysis
• Post-thrombolysis: Maintain SBP below 180 mmHg and DBP below 105 mmHg for 24 hours (q15min BP monitoring for 2h, then q30min for 6h)

Avoid: Sublingual agents (unpredictable), nifedipine short-acting, excessive lowering (cerebral hypoperfusion).

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3. Risks and benefits:

Benefits:

• NNT = 7-10 for excellent outcome (mRS 0-1) at 3 months
• At 3.5 hours, benefit still present (OR 1.4-1.7 for functional independence vs placebo)
• Absolute risk reduction ~10-15% for good outcome
• Moderate stroke (NIHSS 8) is ideal range for benefit (minor strokes NIHSS below 4 have smaller benefit, severe strokes NIHSS greater than 20 higher ICH risk)

Risks:

• Symptomatic intracranial hemorrhage (sICH): 6-7% (vs 1-2% without lysis)
• Mortality from sICH: 40-60% if occurs
• Other bleeding: Systemic bleeding (GI, GU, surgical site - concern for hernia repair site)
• Risk factors for sICH in this patient: Age 76 (moderate risk), BP 210/115 (increases risk if not controlled), recent surgery (local bleeding concern)

Risk-benefit discussion: I would explain to patient/family that thrombolysis offers ~10-15% absolute improvement in good outcome, but carries 6-7% risk of brain hemorrhage (half of which may be fatal). Net benefit is positive (NNT ~10, NNH ~15-20 for sICH), but individualized decision considering surgery timing.

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4. CT angiography and thrombectomy:

YES, recommend CTA:

• Hyperdense MCA sign on CT suggests thrombus in M1/M2 segment (large vessel occlusion)
• NIHSS 8 (≥6 is thrombectomy threshold)
• Within 6-hour window (CTA alone sufficient, no need for perfusion imaging)
• Thrombectomy criteria: LVO (ICA, M1, proximal M2), NIHSS ≥6, ASPECTS ≥6, premorbid mRS 0-2 (patient is mRS 1), within 6 hours
• Bridging therapy: If LVO confirmed, patient should receive both IV alteplase and thrombectomy without delay (door-to-needle first, then proceed to angio suite)

CTA findings to assess:

• Site of occlusion (ICA, M1, M2)
• Collateral score (predicts penumbra salvageability)
• Clot burden score

Thrombectomy benefit: NNT = 3-7 for functional independence; superior outcomes when combined with IV tPA.

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5. Dual antiplatelet therapy (DAPT) consideration:

Aspirin 100 mg + clopidogrel 75 mg (recent stent):

Impact on thrombolysis:

• NOT an absolute contraindication (guidelines contraindicate therapeutic anticoagulation, not antiplatelet therapy)
• However, DAPT increases bleeding risk, particularly sICH risk (estimated 1.5-2× increase)
• Recent stent suggests coronary artery disease; stopping DAPT risks stent thrombosis (catastrophic outcome)

Decision-making:

• I would still proceed with thrombolysis given moderate stroke severity (NIHSS 8), time window (3.5h), and favorable imaging (ASPECTS 9)
• Acknowledge increased bleeding risk to patient/family (~10-12% sICH risk vs 6-7% baseline)
• Cannot stop antiplatelet therapy acutely (stent thrombosis risk)
• Ensure BP is well-controlled (below 185/110 pre-lysis, below 180/105 post-lysis) to mitigate bleeding risk
• Consider thrombectomy as primary strategy if large vessel occlusion confirmed (lower sICH risk than IV tPA, though bridging tPA+thrombectomy still recommended if eligible)

Post-lysis plan:

• Do NOT give additional antiplatelet for 24h post-lysis
• Resume aspirin + clopidogrel at 24h if no hemorrhagic transformation on repeat CT
• Coordinate with cardiology regarding DAPT duration (recent stent requires ongoing therapy)

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Viva 2: Posterior Circulation Stroke and Basilar Thrombectomy

Scenario: A 64-year-old woman is brought to ED by ambulance at 08:00 with sudden-onset vertigo, diplopia, and weakness. Paramedics report she was normal when she went to bed at 23:00 last night; her husband found her drowsy and ataxic at 07:30 this morning (wake-up stroke). On examination: GCS 12 (E3V4M5), bilateral ptosis, complex ophthalmoplegia, left-sided limb ataxia, power 4/5 all limbs, dysarthria. BP 165/92 mmHg, HR 88 bpm regular, glucose 7.2 mmol/L. CT brain: hyperdense basilar artery sign, no hemorrhage. CTA: basilar artery occlusion, pc-ASPECTS 8.

Questions:

1. What is the likely diagnosis and anatomical localization?
2. Is this patient eligible for reperfusion therapy despite wake-up presentation?
3. What are the treatment options and evidence for basilar artery occlusion?
4. What are the prognostic considerations and complications?
5. How would you manage this patient in ICU post-thrombectomy?

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Model Answer:

1. Diagnosis and localization:

Diagnosis: Posterior circulation stroke, specifically basilar artery thrombosis

Anatomical localization:

• Basilar artery territory supplies:
  • Brainstem (pons, midbrain)
  • Cerebellum (via superior cerebellar artery, anterior inferior cerebellar artery)
  • Thalamus and occipital lobes (via posterior cerebral arteries)

Clinical features localizing to basilar artery:

• Bilateral cranial nerve deficits: Bilateral ptosis, ophthalmoplegia (CN III, IV, VI nuclei in midbrain/pons)
• Ataxia: Cerebellar or pontine involvement
• Altered consciousness (GCS 12): Reticular activating system in brainstem
• Motor weakness (4/5 all limbs): Corticospinal tracts in pons/midbrain (may progress to quadriplegia)
• Dysarthria: Pontine or cerebellar involvement

Hyperdense basilar artery sign on CT brain is pathognomonic for basilar thrombosis (sensitivity 30-50%, specificity greater than 95%).

Natural history: Basilar artery occlusion has 70-90% mortality with medical management alone; high risk of progression to locked-in syndrome or coma.

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2. Eligibility for reperfusion therapy (wake-up stroke):

Wake-up stroke: Last known well 23:00, symptoms discovered 07:30 = unknown time of onset (could be 0-8.5 hours).

Standard thrombolysis criteria require known onset ≤4.5h, so patient not eligible based on time alone.

However, imaging-based selection may allow reperfusion:

MRI DWI-FLAIR mismatch:

• If DWI hyperintense but FLAIR negative, suggests stroke below 4.5h → eligible for thrombolysis (WAKE-UP trial criteria)
• Would require urgent MRI (if available and time-efficient)

CT perfusion or MRI perfusion imaging:

• Core below 70 mL, mismatch ratio ≥1.8, mismatch volume ≥15 mL → eligible for thrombectomy up to 6-16h (DEFUSE-3 criteria)
• Even up to 24 hours if DAWN criteria met (age-specific NIHSS and core volume thresholds)

Posterior circulation considerations:

• Extended time window often considered for basilar occlusion due to:
  • Brainstem tolerance to ischemia (longer penumbra survival)
  • Catastrophic natural history (70-90% mortality untreated)
  • Limited alternative options
• Some centers consider thrombolysis up to 6-12 hours for basilar occlusion (off-label, individualized decision)
• Thrombectomy increasingly performed up to 24h for basilar occlusion with favorable imaging

This patient:

• pc-ASPECTS 8 (good, limited infarct), CTA confirms basilar occlusion
• I would recommend:
  • Urgent MRI (if rapid access) to assess DWI-FLAIR mismatch (if negative FLAIR, consider thrombolysis)
  • CT perfusion to quantify core and penumbra (if favorable, proceed to thrombectomy regardless of time)
  • If imaging unavailable or time-prohibitive, proceed directly to thrombectomy given basilar occlusion, limited infarct (pc-ASPECTS 8), and wake-up presentation likely within 8h window

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3. Treatment options and evidence:

IV thrombolysis:

• Limited evidence specific to basilar occlusion (no dedicated RCT)
• Observational data suggests benefit if given within 6-12h (recanalization rate 30-50%)
• If DWI-FLAIR mismatch present, WAKE-UP trial supports thrombolysis
• I would administer IV alteplase if patient meets DWI-FLAIR mismatch criteria OR if thrombectomy delayed (bridging therapy)

Endovascular thrombectomy:

• BEST trial (PMID: 37990444): Thrombectomy vs medical therapy in basilar occlusion (n=340); primary outcome (mRS 0-3) 42% thrombectomy vs 32% medical (p=0.14, not significant); mortality 38% vs 43%
• BASICS trial (PMID: 37990442): Suggested benefit in selected patients with good collaterals, limited infarct
• Pooled observational data: Recanalization achieved in 70-85%, but functional outcome variable (mRS 0-3 in 30-50%)

Current practice (despite mixed trial results):

• Thrombectomy recommended for basilar occlusion if:
  • pc-ASPECTS ≥8 (or small core on perfusion imaging)
  • Good collateral circulation
  • Premorbid mRS 0-2
  • Presenting within 6-24h (with favorable imaging)
• This patient meets criteria: pc-ASPECTS 8, likely within 8h, premorbid independent
• I would recommend thrombectomy given poor natural history and favorable imaging

Technique: Stent retriever, contact aspiration, or combination approach via femoral artery access.

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4. Prognostic considerations and complications:

Prognosis:

• Untreated basilar occlusion: 70-90% mortality
• Post-thrombectomy: 30-50% achieve functional independence (mRS 0-3), mortality 30-40%
• Favorable prognostic factors: Younger age (below 65), good pc-ASPECTS (≥8), early reperfusion, absence of coma at presentation
• Poor prognostic factors: Coma (GCS ≤8), fixed dilated pupils, extensive brainstem infarction, delayed presentation (greater than 12h)

This patient has moderate prognosis: Age 64, GCS 12 (not coma), pc-ASPECTS 8, within 8h; estimated 40-50% chance of good outcome with thrombectomy.

Complications:

Early (hours to days):

• Hemorrhagic transformation: 5-10% (lower risk than anterior circulation due to smaller infarct volumes)
• Brainstem edema: May cause obstructive hydrocephalus (4th ventricle compression), respiratory failure, autonomic instability
• Progression to locked-in syndrome: Quadriplegia, anarthria, preserved consciousness (bilateral ventral pontine infarction)
• Coma: Reticular activating system injury

Intermediate (days to weeks):

• Aspiration pneumonia: Dysphagia from brainstem involvement (40-60%)
• Respiratory failure: Central hypoventilation, apnea (may require prolonged ventilation or tracheostomy)
• Cardiac arrhythmias: Autonomic dysregulation
• DVT/PE: Immobility, quadriparesis

Late:

• Posterior cerebral artery (PCA) territory infarction: If basilar top-of-basilar thrombus extends to PCAs (bilateral visual field defects, memory impairment, thalamic pain syndrome)

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5. ICU management post-thrombectomy:

Airway and ventilation:

• High risk of intubation: GCS 12 with brainstem stroke may deteriorate; assess airway reflexes, bulbar function
• Intubate if: GCS below 8-9, loss of protective reflexes, respiratory failure (hypoventilation, apnea)
• Target: SpO₂ 94-98%, normocapnia (PaCO₂ 35-45 mmHg)

Blood pressure:

• Permissive hypertension (allow SBP up to 220 mmHg) if no thrombolysis given
• Post-thrombectomy: Maintain MAP 70-100 mmHg (avoid extremes); individualize based on collateral dependence
• Avoid hypotension (may worsen penumbral ischemia) and severe hypertension (hemorrhagic transformation risk)

Neurological monitoring:

• GCS, pupils, cranial nerves, limb power q1-2h initially
• Watch for deterioration: Progressive drowsiness, coma, respiratory failure (may indicate edema, hemorrhage, or reocclusion)
• Repeat imaging (CT brain) at 24h or if clinical deterioration

Glycemic control:

• Target glucose 6-10 mmol/L (insulin infusion if needed)

Temperature:

• Normothermia below 37.5°C (paracetamol, cooling devices)

Swallow assessment:

• Nil-by-mouth until formal swallow assessment (speech pathology, video fluoroscopy)
• High aspiration risk (brainstem stroke with dysarthria, dysphagia)
• NG tube for nutrition/medications if unsafe swallow

Antithrombotic therapy:

• If thrombectomy alone (no IV tPA): Start aspirin 300 mg at 24h (after CT confirms no hemorrhage)
• If bridging IV tPA given: Delay aspirin 24h post-thrombolysis
• DVT prophylaxis: IPC devices, LMWH (enoxaparin 40 mg SC daily) if no hemorrhagic transformation

Rehabilitation:

• Early PT/OT involvement for positioning, passive range of motion
• Speech pathology for dysphagia management, communication strategies

Prognosis discussion:

• Early family meeting to discuss uncertain prognosis (40-50% good outcome, risk of severe disability or death)
• Assess patient's prior wishes regarding prolonged ventilation, tracheostomy, severe disability

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Summary

Ischemic stroke is a time-critical neurological emergency requiring immediate assessment, imaging, and reperfusion therapy (IV alteplase within 4.5h, endovascular thrombectomy within 6-24h for large vessel occlusion). Intensive care management focuses on neuroprotective strategies (permissive hypertension unless thrombolysed, normoglycemia, normothermia), complication surveillance (malignant MCA syndrome, hemorrhagic transformation, aspiration pneumonia), and secondary prevention (antiplatelet therapy, anticoagulation for atrial fibrillation, risk factor control). Early decompressive craniectomy for malignant MCA syndrome reduces mortality by 50% (NNT = 2). Outcomes depend on age, stroke severity (NIHSS), infarct volume (ASPECTS), time-to-reperfusion, and etiology (TOAST classification). Long-term secondary prevention (BP below 130/80, LDL below 1.8 mmol/L, antiplatelet/anticoagulation) reduces recurrent stroke risk by 50-70%.

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