Makindo Medical Notes

Related Subjects: |Neurological History taking |Causes of Stroke |Ischaemic Stroke |Subarachnoid Haemorrhage |Cerebral Arterial Perfusion and Clinical Correlates |Anterior circulation Brain |Posterior circulation Brain |Acute Stroke Assessment (ROSIER&NIHSS) |Carotid Artery dissection |Vertebral artery dissection

📖 About

• Always consider vertebral artery dissection in a young patient with posterior circulation stroke (esp. dizziness, ataxia, vision loss).
• Accounts for ~10–25% of strokes in young adults (<50 years).
• Pathology: vessel wall tear → intramural haematoma → luminal narrowing/thrombosis → emboli.

⚙️ Aetiology

• Dissection → intraluminal clot → embolisation or local occlusion.
• Common sites: at C1–C2 level or origin of the PICA.
• Connective tissue disorders (Ehlers–Danlos IV, fibromuscular dysplasia) predispose.
• Triggered by minor trauma or sudden neck movements (e.g. chiropractor, hairdresser basin, yoga, sports).
• Rare but severe: basilar artery dissection → high mortality.

🧬 Predisposing Factors

• 🦴 Neck trauma (rotation/flexion stresses).
• 🧬 Connective tissue disorders: Ehlers–Danlos IV, fibromuscular dysplasia, cystic medial necrosis.
• ⚡ Genetic conditions: Marfan, COL1 mutations, osteogenesis imperfecta type 1.
• 🧠 Migraine, family history of dissection.
• 🚺 Pregnancy and postpartum state.
• 🚬 Smoking as an acquired risk factor.

🩺 Clinical Presentation

• 🪖 Headache/neck pain (often sudden, occipital, unilateral).
• 🎯 Posterior circulation stroke signs: dizziness, diplopia, vertigo, dysarthria, ataxia.
• 🧑‍⚕️ Lateral medullary (Wallenberg) syndrome: ipsilateral facial numbness, contralateral body numbness, dysphagia, hoarseness, Horner’s syndrome.
• 💢 Intracranial dissections: may rupture → subarachnoid haemorrhage (SAH) (up to 50% cases).

🔍 Investigations

• 🖼️ CTA: Best initial test – shows vessel narrowing, occlusion, or dissection flap.
• 🧲 MRI/MRA with fat suppression: Characteristic crescent sign = intramural haematoma.
• 📡 Doppler ultrasound: May suggest occlusion or flow turbulence, but less sensitive in vertebral arteries.

⚖️ Management

• 💊 Anticoagulation (warfarin) for 3–6 months was traditional; evidence is mixed.
• 💊 Dual antiplatelet therapy (aspirin + clopidogrel) is now often used as an alternative, esp. if SAH risk.
• 📉 Choice of antithrombotic depends on location: – Extracranial dissection → antithrombotic therapy reasonable. – Intracranial dissection → higher SAH risk → anticoagulation often avoided.
• 🧑‍⚕️ Basilar dissections: poor prognosis, sometimes considered for stenting but evidence limited.
• 📆 Follow-up vascular imaging at 3–6 months to assess healing.

💡 Exam Pearls:
– Think vertebral dissection in a young patient with posterior circulation stroke + neck pain.
– Crescent sign on MRI is classic.
– Management: antithrombotics (antiplatelet or anticoagulation) but intracranial dissections carry SAH risk.