Cerebrovascular Disorders Flashcards
Define stroke.
A cerebrovascular event causing disrupted blood supply to the brain, characterized by sudden focal/global cerebral dysfunction lasting >24 hours or causing death.
What are the main types of stroke?
Ischaemic Stroke (87%)
Haemorrhagic Stroke (13%)
List the subtypes of haemorrhagic stroke.
Intracerebral Haemorrhage (e.g., intraparenchymal or intraventricular bleeding).
Subarachnoid Haemorrhage (bleeding between the pia and arachnoid mater).
What are the modifiable risk factors for stroke?
Hypertension, diabetes, smoking, hyperlipidemia, atrial fibrillation, obesity, physical inactivity, and alcohol misuse.
Name some non-modifiable risk factors for stroke.
Age, male sex, family history, and genetic predisposition.
What are the main mechanisms of ischaemic stroke?
Embolism (e.g., from atrial fibrillation).
Thrombosis (local clot formation due to atherosclerosis).
Systemic hypoperfusion (e.g., cardiac arrest).
Cerebral venous sinus thrombosis.
What classification system is used for ischaemic strokes?
The Bamford Classification, which categorizes strokes into:
Total Anterior Circulation Stroke (TACS).
Partial Anterior Circulation Stroke (PACS).
Lacunar Stroke (LACS).
Posterior Circulation Stroke (POCS).
What are the common symptoms of stroke?
Weakness, sensory disturbances, visual disturbances, speech disturbances, ataxia, dysphagia, reduced consciousness, and pain.
What type of headache is associated with subarachnoid haemorrhage?
A “thunderclap” headache with sudden onset.
What is the first-line investigation for suspected stroke?
Non-contrast CT of the brain to differentiate between ischaemic and haemorrhagic strokes
Outline the acute management of ischaemic stroke.
IV thrombolysis with alteplase (if <4.5 hours since onset).
Mechanical thrombectomy (for large vessel occlusions).
Antiplatelet therapy (e.g., aspirin).
What is the immediate management of haemorrhagic stroke?
Blood pressure control, neurosurgical intervention (if indicated), and monitoring for increased intracranial pressure.
What are key strategies for secondary prevention of stroke?
Antiplatelets (e.g., aspirin, clopidogrel).
Anticoagulation for atrial fibrillation.
Statin therapy for lipid management.
Lifestyle modifications (e.g., diet, smoking cessation, exercise).
List complications of stroke.
Long-term disability (e.g., hemiparesis).
Speech difficulties (aphasia, dysarthria).
Swallowing difficulties (dysphagia).
Post-stroke depression and fatigue.
Recurrent strokes.
What is a Transient Ischaemic Attack (TIA)?
A TIA is a temporary interruption of blood flow to the brain, resulting in stroke-like symptoms that resolve completely within 24 hours without causing permanent damage.
Why is a TIA considered a medical emergency?
It is a warning sign for potential future strokes, with a significant risk in the following hours to days.
What are the main causes of a TIA?
Atherosclerosis
Thromboembolic events
Cardioembolic sources (e.g., atrial fibrillation)
List common risk factors for a TIA.
Hypertension
Diabetes mellitus
Hyperlipidemia
Smoking
Atrial fibrillation
Carotid artery stenosis
What symptoms might indicate a TIA?
Sudden unilateral weakness or numbness
Dysphasia or aphasia
Amaurosis fugax (temporary vision loss in one eye)
Vertigo or ataxia
Diplopia
How is a TIA diagnosed?
Primarily clinical history supported by investigations:
Brain imaging: MRI with DWI preferred.
Vascular imaging: Carotid Doppler, CT/MR angiography.
Cardiac assessment: ECG and echocardiogram to rule out embolic sources.
Blood tests: FBC, glucose, cholesterol, and clotting studies
What scoring system is used to assess TIA risk?
The ABCD2 score evaluates the risk of stroke following a TIA.
What is the immediate management of a suspected TIA?
Initiate antiplatelet therapy (aspirin 300 mg daily).
Admit high-risk cases for urgent imaging and evaluation.
What long-term management strategies are used?
Antiplatelets: Clopidogrel or aspirin with dipyridamole.
Statin therapy: For cholesterol control.
Blood pressure control: Using ACE inhibitors or other antihypertensives.
Anticoagulation: In cases with atrial fibrillation.
Lifestyle modifications (e.g., smoking cessation, healthy diet).
What is the prognosis after a TIA?
Without intervention, the risk of a stroke within 90 days is approximately 10-20%, most within the first 48 hours.
What is the role of carotid endarterectomy in TIA management?
Indicated for patients with symptomatic carotid artery stenosis (>70%) to prevent further events.
What is a Subarachnoid Haemorrhage (SAH)?
SAH is bleeding into the subarachnoid space, typically caused by the rupture of a cerebral aneurysm, often at the Circle of Willis. It accounts for 5% of strokes.
What are common causes of Subarachnoid Haemorrhage?
Berry aneurysms: Most common, often linked to hypertension or genetic conditions like autosomal dominant polycystic kidney disease (ADPKD).
Arteriovenous malformations (AVMs).
Trauma.
What is the classical presentation of SAH?
Thunderclap headache: Sudden, severe headache reaching peak intensity within seconds.
Often described as the worst headache ever experienced.
Associated symptoms: vomiting, confusion, neck stiffness, reduced consciousness, or focal neurological signs.
What are risk factors for SAH?
Smoking.
Hypertension.
Heavy alcohol use.
Family history of aneurysms.
Genetic conditions (e.g., Ehlers-Danlos syndrome, ADPKD).
How is SAH diagnosed?
CT Head: Detects >95% of SAHs within 6 hours of symptom onset.
Lumbar Puncture (if CT is inconclusive):
Performed >12 hours post-onset to check for xanthochromia (CSF discoloration due to RBC breakdown).
Xanthochromia confirms SAH even with a negative CT.
Angiography: Identifies the source of bleeding.
What is xanthochromia, and how is it detected?
Yellow discoloration of CSF caused by bilirubin from RBC breakdown.
Detected via spectrophotometry after a lumbar puncture performed >12 hours after symptom onset.
What are key findings on cerebrospinal fluid (CSF) analysis in SAH?
Appearance: Initially blood-stained, later xanthochromic (>12 hours).
Opening pressure: Elevated.
RBC count: Elevated.
WBC count: Elevated (WBC-to-RBC ratio ~1:1000).
Glucose: Normal.
Protein: Elevated.
What imaging features are seen in SAH?
CT scan: Hyperdensity around sulci/gyri or basal cisterns.
Often located near the Circle of Willis.
How is SAH managed in acute settings?
Initial stabilization: Airway, breathing, circulation (ABC).
Blood pressure control: Maintain systolic BP <160 mmHg to prevent rebleeding.
Definitive management:
Endovascular coiling or surgical clipping of the aneurysm.
Early treatment (<72 hours) reduces rebleeding risk.
Nimodipine: Reduces risk of delayed ischemia from cerebral vasospasm