Acute Stroke
Summary
Stroke is a medical emergency caused by interrupted blood supply to the brain, leading to rapid neuronal death and neurological deficit. It is the second leading cause of death globally and a leading cause of disability. Strokes are classified as ischaemic (85%, due to arterial occlusion) or haemorrhagic (15%, due to vessel rupture). "Time is Brain" - every minute of ischaemia destroys 1.9 million neurons. Rapid recognition (FAST), emergency imaging, and timely treatment (thrombolysis, thrombectomy) have revolutionised outcomes. Secondary prevention is critical to reduce recurrence.
Key Facts
- Mortality: 10-15% at 30 days; 25% at 1 year
- Disability: 50% of survivors have long-term disability
- Types: Ischaemic 85%, Haemorrhagic 15%
- Time Windows: Thrombolysis <4.5h; Thrombectomy up to 24h (select patients)
- Target: Door-to-needle <60 minutes (ideally <45)
- Recurrence: 10% at 1 year without secondary prevention
- Neuronal Loss: 1.9 million neurons/minute during ischaemia
Clinical Pearls
High-Yield Points:
- FAST: Face drooping, Arm weakness, Speech difficulty, Time to call emergency
- CT head is mandatory before any treatment decision
- "Wake-up stroke" may still be eligible for reperfusion (MRI-based selection)
- Large vessel occlusion (LVO) requires thrombectomy - check for it
- Avoid rapid BP lowering unless thrombolysis/haemorrhagic
- Antiplatelet dual therapy (DAPT) for 21 days post-minor stroke/TIA reduces recurrence by 25%
Why This Matters Clinically
Stroke is a leading cause of death and disability affecting all age groups. It is time-critical - delays of even minutes worsen outcomes. Every healthcare professional should recognise stroke immediately and understand the acute management pathway. Secondary prevention reduces recurrence risk from 10% to 2-3% per year.
Prevalence and Incidence
| Metric | Value |
|---|---|
| Annual Incidence (UK) | 100,000 strokes/year |
| Prevalence | 1.3 million stroke survivors (UK) |
| Age: Mean age | 74 years |
| Sex | Slightly more common in males |
| Global Burden | 2nd leading cause of death worldwide |
Risk Factors
Non-Modifiable:
- Age (risk doubles each decade over 55)
- Male sex (until menopause, then equal)
- Family history
- Previous stroke or TIA
- Ethnic minority groups (higher risk)
Modifiable (Target for Prevention):
- Hypertension (most important)
- Atrial fibrillation
- Diabetes mellitus
- Smoking
- Dyslipidaemia
- Obesity
- Physical inactivity
- Excessive alcohol
- Carotid stenosis
Ischaemic Stroke (85%)
Mechanisms:
- Large Vessel Atherosclerosis: Carotid/vertebral stenosis with artery-to-artery embolism
- Cardioembolic: Thrombus from AF, mechanical valve, LV thrombus
- Small Vessel Disease (Lacunar): Lipohyalinosis of perforating arteries
- Other: Dissection, vasculitis, hypercoagulable states
The Ischaemic Penumbra:
- Core: Irreversibly damaged (CBF <10 mL/100g/min)
- Penumbra: At-risk but salvageable tissue (CBF 10-20 mL/100g/min)
- Target of reperfusion therapy
Ischaemic Cascade:
- Energy failure (ATP depletion)
- Ionic pump failure → Depolarisation
- Glutamate release → Excitotoxicity
- Calcium influx → Cell death
- Inflammation → Secondary damage
Haemorrhagic Stroke (15%)
Intracerebral Haemorrhage (10%):
- Hypertensive (basal ganglia, thalamus, pons, cerebellum)
- Cerebral amyloid angiopathy (lobar haemorrhage in elderly)
- Anticoagulation-related
- Vascular malformations
Subarachnoid Haemorrhage (5%):
- Berry aneurysm rupture (85%)
- AV malformation
- Trauma
Recognition: FAST
| Letter | Sign | Description |
|---|---|---|
| F | Face | Facial droop (ask to smile) |
| A | Arm | Arm weakness (raise both arms) |
| S | Speech | Slurred or absent speech |
| T | Time | Time to call 999 |
Anterior Circulation (Carotid Territory)
| Syndrome | Vessel | Features |
|---|---|---|
| Total Anterior Circulation (TACS) | MCA ± ACA | All 3: Hemiparesis, hemisensory, higher cortical dysfunction |
| Partial Anterior Circulation (PACS) | MCA branch | 2 of 3 above |
| Lacunar (LACS) | Perforating arteries | Pure motor, pure sensory, ataxic hemiparesis |
Higher Cortical Features:
Posterior Circulation (Vertebrobasilar)
| Feature | Frequency |
|---|---|
| Vertigo | Common |
| Diplopia | Common |
| Ataxia | Common |
| Dysarthria | Common |
| Visual field defect | Occipital involvement |
| Decreased consciousness | Brainstem involvement |
Red Flag: Posterior circulation stroke is easily missed - have high suspicion with "dizziness + any other neuro sign"
Neurological Assessment
Conscious Level: GCS
Cranial Nerves:
- Facial weakness (upper vs lower motor)
- Eye movements (gaze deviation toward lesion)
- Visual fields
Motor:
- Power in all 4 limbs
- Pronator drift
- Tone (may be flaccid acutely)
Sensation:
- Light touch, pain, proprioception
Cerebellar:
- Ataxia, dysmetria, dysdiadochokinesia
Speech:
- Dysarthria vs dysphasia
NIHSS (National Institutes of Health Stroke Scale)
- Standardised assessment of stroke severity
- Score 0-42
- Used to guide treatment decisions
- NIHSS ≥6 suggests large vessel occlusion
Immediate (Hyperacute)
| Investigation | Purpose | Timing |
|---|---|---|
| CT Head (Non-contrast) | Exclude haemorrhage | Immediately (<25 mins) |
| CT Angiography | Identify LVO, carotid stenosis | With plain CT |
| Blood Glucose | Exclude hypoglycaemia | Immediately |
| ECG | AF detection | Immediately |
Acute Phase
| Investigation | Purpose |
|---|---|
| CT Perfusion | Penumbra assessment for extended window |
| MRI Brain | Diffusion-weighted for acute infarct; wake-up stroke |
| Echocardiogram | Cardiac source of embolism |
| Carotid Doppler | Stenosis (if anterior circulation) |
| 24-72h cardiac monitoring | Paroxysmal AF |
| FBC, U&Es, coagulation, lipids, HbA1c | Baseline and risk factors |
By Mechanism (TOAST)
- Large artery atherosclerosis
- Cardioembolic
- Small vessel occlusion (lacunar)
- Stroke of other determined aetiology
- Stroke of undetermined aetiology (cryptogenic)
By Timing
| Term | Definition |
|---|---|
| TIA | Symptoms <24h, no infarct on imaging |
| Minor Stroke | NIHSS ≤3 |
| Major Stroke | NIHSS > |
Bamford Classification (Clinical)
- TACS, PACS, LACS, POCS (Posterior Circulation Syndrome)
Hyperacute Phase (Golden Hour)
1. Recognition and Transport:
- Pre-alert stroke team
- FAST positive → Emergency department
2. Immediate Assessment:
- ABC, glucose, NIHSS
- CT head within 25 minutes
3. Reperfusion Therapy (Ischaemic Only):
IV Thrombolysis (Alteplase 0.9 mg/kg):
- Eligibility: <4.5 hours from onset
- Contraindications: Active bleeding, recent surgery, haemorrhage on CT
- NNT: 10 for improved outcome
Mechanical Thrombectomy:
- Large vessel occlusion (ICA, M1, M2, basilar)
- Up to 6 hours (standard); up to 24 hours (selected with perfusion imaging)
- NNT: 2-3 for improved outcome
- Transformative for LVO stroke
4. Haemorrhagic Stroke:
- Reverse anticoagulation (if applicable)
- BP control (target SBP <140 mmHg)
- Neurosurgical referral if indicated
Acute Phase (24-72 hours)
If Thrombolysed:
- BP control (SBP <180/105)
- No aspirin for 24 hours
- Repeat imaging if deteriorates
All Ischaemic Stroke:
- Aspirin 300 mg once daily for 14 days
- Consider clopidogrel loading if high-risk TIA/minor stroke
- DVT prophylaxis (pneumatic compression)
- Swallow screen before oral intake
- Early mobilisation (AVERT trial - avoid bed rest)
- Stroke unit care (reduces mortality)
Secondary Prevention
Antiplatelets:
- Clopidogrel 75 mg long-term (first-line, NICE)
- OR Aspirin + Dipyridamole (if clopidogrel contraindicated)
- DAPT (Aspirin + Clopidogrel) for 21 days post-minor stroke/TIA
Anticoagulation (if AF):
- DOAC (Apixaban, Rivaroxaban, Edoxaban)
- Start 2-14 days post-stroke depending on size
Blood Pressure:
- Target <130/80 after acute phase
- ACE-I + CCB/diuretic often used
Lipids:
- High-intensity statin (Atorvastatin 80 mg)
- LDL target <1.8 mmol/L
Carotid Revascularisation:
- Symptomatic stenosis ≥50%: Endarterectomy within 2 weeks
Lifestyle:
- Smoking cessation, exercise, diet, alcohol reduction
Acute
| Complication | Management |
|---|---|
| Haemorrhagic transformation | Reverse anticoagulation, BP control |
| Cerebral oedema | Osmotherapy, decompressive craniectomy |
| Aspiration pneumonia | NBM if swallow unsafe, antibiotics |
| Seizures | Usually not prophylaxis; treat if occur |
| DVT/PE | Pneumatic compression, LMWH when safe |
Chronic
- Spasticity
- Post-stroke depression (30-50%)
- Cognitive impairment/dementia
- Epilepsy (2-5%)
- Chronic pain
- Fatigue
Mortality
| Timeframe | Mortality |
|---|---|
| 30 days | 10-15% (ischaemic), 30-50% (haemorrhagic) |
| 1 year | 25% |
| 5 years | 50% |
Functional Outcome
- 50% of survivors have permanent disability
- 25% require nursing home care
- Better outcomes with: younger age, lower NIHSS, early reperfusion, stroke unit care
Key Guidelines
| Guideline | Organisation | Year |
|---|---|---|
| Stroke and TIA | NICE NG128 | 2019 (Updated 2022) |
| Acute Ischaemic Stroke | AHA/ASA | 2019 |
| Mechanical Thrombectomy | RCP | 2021 |
Key Trials
- NINDS (1995): Thrombolysis works
- MR CLEAN, EXTEND-IA, ESCAPE (2015): Thrombectomy for LVO
- DAWN, DEFUSE-3 (2018): Extended time window thrombectomy
- CHANCE, POINT: Dual antiplatelet for minor stroke/TIA
What is a Stroke?
A stroke happens when blood flow to part of your brain is interrupted, either by a blockage (clot) or a bleed. Without blood, brain cells start to die within minutes, which is why stroke is a medical emergency.
How do I recognise a stroke? (FAST)
- Face: Has their face dropped on one side?
- Arms: Can they raise both arms?
- Speech: Is their speech slurred or strange?
- Time: Time to call 999 immediately
What happens in hospital?
- A brain scan is done immediately to check for bleeding or clot
- If it's a clot, you may receive clot-busting medication or have the clot removed
- If it's a bleed, different treatment is needed
- After the emergency phase, rehabilitation helps recovery
How can I prevent another stroke?
- Take all medications as prescribed (blood thinners, cholesterol tablets, BP tablets)
- Stop smoking
- Eat a heart-healthy diet, exercise regularly
- Manage diabetes and high blood pressure
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Powers WJ, et al. Guidelines for the Early Management of Patients With Acute Ischemic Stroke. Stroke. 2019;50(12):e344-e418. PMID: 30662432
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NICE. Stroke and transient ischaemic attack in over 16s: diagnosis and initial management (NG128). 2019. nice.org.uk
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Goyal M, et al. Endovascular thrombectomy after large-vessel ischaemic stroke: a meta-analysis. Lancet. 2016;387(10029):1723-1731. PMID: 26898852
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Johnston SC, et al. Clopidogrel and Aspirin in Acute Ischemic Stroke and High-Risk TIA (POINT). N Engl J Med. 2018;379(3):215-225. PMID: 29766750
Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. It does not replace professional medical judgement.