MRCP Neurology: Mastering Acute Stroke Management Guidelines

As medical professionals, understanding and applying current guidelines for acute stroke management is not just a clinical imperative but also a high-yield topic for the MRCP examination. Stroke is a common and devastating condition, demanding swift, accurate diagnosis and immediate intervention. This guide will distill the essential guidelines you need to master for your MRCP exam, ensuring you're well-prepared to ace neurology questions and, more importantly, manage real-world emergencies.

The Golden Hour(s): Initial Assessment and Triage

Time is brain! The cornerstone of acute stroke management is rapid assessment and decision-making. For MRCP, understand the following:

1. Recognition: Emphasise rapid recognition using tools like the FAST (Face, Arm, Speech, Time) test. While simple, it's crucial for pre-hospital and initial hospital assessment.

2. Immediate History & Examination: Focus on establishing time of symptom onset (or last known well) and assessing severity using scales like the NIH Stroke Scale (NIHSS). This is critical for determining eligibility for acute reperfusion therapies.

3. ABCDE Assessment: Standard resuscitation principles apply. Ensure airway, breathing, and circulation are stable. Monitor vital signs, especially blood pressure and blood glucose.

   • MRCP Tip: Be aware of permissive hypertension in acute ischaemic stroke (up to 220/120 mmHg) if no reperfusion therapy is planned, allowing for adequate cerebral perfusion. Lowering BP too aggressively can worsen ischaemia.

Neuroimaging: The Cornerstone of Diagnosis

Prompt neuroimaging is non-negotiable. The MRCP exam will test your understanding of why certain scans are performed and what they reveal:

1. Non-Contrast CT Head (NCCT): This is the initial imaging modality of choice. Its primary purpose is to rule out intracranial haemorrhage. If haemorrhage is present, thrombolysis is contraindicated.

   • MRCP Focus: Know that early ischaemic changes (e.g., sulcal effacement, hyperdense MCA sign) might be subtle or absent on initial CT, but their presence doesn't contraindicate thrombolysis within the window.

2. CT Angiography (CTA) / CT Perfusion (CTP): Increasingly, these are used, especially in centres offering thrombectomy or for patients presenting in extended time windows.

   • CTA: Identifies large vessel occlusion, crucial for thrombectomy decisions.

   • CTP: Provides information on ischaemic core and penumbra, guiding treatment in selected cases.

Acute Reperfusion Therapies: Thrombolysis and Thrombectomy

These are high-yield areas for MRCP, requiring precise knowledge of indications, contraindications, and time windows.

1. Intravenous Thrombolysis (IVT) with Alteplase:

   • Mechanism: Fibrinolytic agent that breaks down clots.

   • Time Window: Traditionally 4.5 hours from symptom onset. Extended windows (e.g., wake-up stroke, unknown onset time) can be guided by advanced imaging (CTP/DWI-MRI) based on mismatch criteria.

   • **Key Contraindications (Know These for MRCP!):

     • Any evidence of intracranial haemorrhage on NCCT.

     • Active internal bleeding or recent trauma/surgery.

     • Bleeding diathesis (e.g., low platelets, elevated INR from warfarin).

     • Severe uncontrolled hypertension (>185/110 mmHg) before treatment.

     • Previous stroke or head trauma in past 3 months.

     • Rapidly improving symptoms.

     • Minor stroke symptoms (NIHSS 0-4) in some guidelines.

   • Post-Thrombolysis Care: Strict BP control, neurological monitoring, and no antiplatelets/anticoagulants for 24 hours.

2. Mechanical Thrombectomy (MT):

   • Mechanism: Physical removal of a clot using a catheter-based device.

   • Indications: Large vessel occlusion (LVO) in anterior circulation, often identified on CTA.

   • Time Window: Up to 6 hours from symptom onset, but can be extended up to 24 hours in selected patients with favourable imaging (e.g., large penumbra) based on DEFUSE 3 and DAWN trials.

   • MRCP Note: MT is often preferred over or used in addition to IVT for LVOs. Always consider both options in appropriate candidates.

Secondary Prevention: Beyond the Acute Phase

Once the acute phase is managed, preventing recurrence is paramount. MRCP will test your knowledge of appropriate long-term management.

1. Antiplatelet Therapy:

   • Ischaemic Stroke/TIA: Aspirin (initial 300mg loading dose in acute phase after haemorrhage ruled out, then 75mg daily) or Clopidogrel (75mg daily).

   • Dual Antiplatelet Therapy (DAPT): Aspirin + Clopidogrel for a short period (e.g., 21-90 days) in minor stroke/TIA at high risk of recurrence (e.g., ABCD2 score > 4) in the absence of cardioembolic source.

2. Anticoagulation:

   • Indicated for cardioembolic stroke (e.g., Atrial Fibrillation). Direct Oral Anticoagulants (DOACs) are generally preferred over Warfarin.

   • MRCP Nuance: Timing of anticoagulation post-stroke depends on stroke size and haemorrhagic transformation risk (e.g., 1-14 days after stroke, larger strokes warranting longer delay).

3. Blood Pressure Control: Strict long-term management according to general hypertension guidelines.

4. Lipid Management: High-intensity statin therapy (e.g., Atorvastatin 80mg) is recommended, regardless of baseline cholesterol levels.

5. Lifestyle Modifications: Smoking cessation, regular exercise, healthy diet, and managing diabetes.

6. Carotid Endarterectomy / Stenting: Considered for symptomatic carotid artery stenosis (>70%) where the stroke is attributed to the stenosis. Timing is usually deferred from the acute event.

Common Pitfalls and MRCP Red Flags

• Missing time of onset: Critical for reperfusion therapy decisions.

• Delay in imaging: Never delay imaging for any reason if stroke is suspected.

• Inappropriate BP management: Both too high (risk of haemorrhage) and too low (risk of hypoperfusion) are dangerous.

• Overlooking reversible causes: Think about unusual stroke causes like dissection, vasculitis, thrombophilia, especially in younger patients.

Mastering these guidelines will equip you with the knowledge to excel in your MRCP neurology section and become a more competent physician in managing one of medicine's most challenging emergencies. Keep practicing scenarios, focus on the 'why' behind each guideline, and remember that patient safety is always paramount.