Causes of Stroke
Related Subjects:
|Acute Stroke Assessment (ROSIER&NIHSS)
|Atrial Fibrillation
|Atrial Myxoma
|Causes of Stroke
|Ischaemic Stroke
|Cancer and Stroke
|Cardioembolic stroke
|CT Basics for Stroke
|Endocarditis and Stroke
|Haemorrhagic Stroke
|Stroke Thrombolysis
|Brain Herniation syndromes
|Haemorrhagic stroke
|Traumatic Head/Brain Injury
|Acute Hydrocephalus
|Epidural Haematoma
|Subdural haematoma
|Basic Neuroscience
|Basal Ganglia
|Apraxia
|Cerebral Angiography and Perfusion
๐ง Introduction
- Diagnosing the cause of a stroke is like detective work ๐ต๏ธ โ a stroke physician must not only identify stroke but also investigate its cause to prevent recurrence.
- Clues come from careful history and examination: a carotid bruit โ stenosis, atrial fibrillation โ cardioembolism, Hornerโs syndrome โ carotid dissection, or a murmur โ endocarditis.
- Each case requires critical thinking and Bayesian reasoning โ avoid blaming โinnocent bystandersโ like a patent foramen ovale (PFO) without clear evidence.
- When no clear cause is found, the term cryptogenic stroke is used โ it is safer to accept uncertainty than to treat wrongly.
โ ๏ธ Challenges for a Stroke Physician
- Distinguish stroke from mimics (e.g. seizure, migraine, hypoglycaemia).
- Determine the likely cause in each patient and tailor prevention accordingly.
- Balance overlapping risks (e.g. AF + carotid stenosis โ anticoagulation vs surgery).
- Communicate the plan clearly to patients and families.
- Focus investigations on high-yield tests, avoid unnecessary or harmful ones.
๐งฉ Mechanisms of Ischaemic Stroke
- ๐ฉธ In situ arterial thrombosis (atherosclerosis of large vessels).
- ๐ฉธ Small vessel occlusion (lipohyalinosis, hypertension, CADASIL).
- โก Embolism: artery-to-artery (ruptured plaque) or cardioembolic (AF, thrombus, endocarditis, tumour).
- ๐ซ Paradoxical embolism (e.g. PFO, right-to-left shunt).
- ๐ง Low flow states: hypotension, shock โ watershed infarcts.
๐งฌ Pathological Causes of Ischaemic Stroke
- ๐ Large vessel atherosclerosis: cervical (carotid, vertebral) and intracranial (MCA, ACA, PCA).
- ๐ซ Cardioembolism: AF, mitral stenosis, left atrial thrombus, endocarditis, cardiac tumours.
- ๐งฉ Small vessel disease: hypertension, CADASIL, Fabryโs disease, diabetes.
- ๐ฉบ Cervical dissections: carotid or vertebral arteries.
- ๐ฅ Vasculitis: primary (e.g. giant cell arteritis) or secondary (autoimmune/infective).
- ๐ช๏ธ Angiopathies: migraine-related, postpartum, drug-induced, RCVS.
- ๐งฌ Monogenic syndromes: CADASIL, CARASIL, MELAS, Fabryโs.
- ๐งช Haematological causes: polycythaemia, thrombocytosis, sickle cell disease, thrombophilias.
๐ฉธ Aetiologies of Haemorrhagic Stroke
- โก Hypertension: deep bleeds (basal ganglia, pons, thalamus).
- ๐ง Cerebral amyloid angiopathy (CAA): lobar bleeds in older adults.
- ๐ Vascular anomalies: AVMs, cavernomas, dural AV fistula, aneurysms.
- ๐ฉบ Coagulopathy: anticoagulants (warfarin, DOACs), platelet disorders, thrombolysis.
- ๐ฉธ Cerebral venous thrombosis: venous back-pressure โ secondary haemorrhage.
- ๐ญ Other: brain tumours (primary/metastatic) bleeding into lesion.
๐ฅ Mechanisms of Haemorrhage
- ๐ Structural weaknesses: aneurysms, AVMs, Charcot-Bouchard microaneurysms.
- โ๏ธ Venous back pressure: e.g. cerebral venous sinus thrombosis.
- ๐ฉบ Coagulopathy: anticoagulants, bleeding disorders, DOACs.
๐ฅ Causes of Subarachnoid Haemorrhage
- ๐ Saccular (berry) aneurysm rupture.
- ๐ AV malformation.
- โ Idiopathic/perimesencephalic.
- ๐ค Trauma.
- ๐ Anticoagulants or thrombolysis.
- ๐ช๏ธ Reversible cerebral vasoconstriction syndrome (RCVS).
- ๐ฉธ Intracranial artery dissection.
๐งฌ Monogenic Causes of Stroke
- CADASIL / CARASIL.
- MELAS (mitochondrial encephalopathy).
- Fabryโs disease.
- Sickle cell disease.