Podcast
Questions and Answers
What is a stroke primarily defined as?
What is a stroke primarily defined as?
Which of the following factors is a risk factor for stroke prevention?
Which of the following factors is a risk factor for stroke prevention?
What is the term used to describe a temporary blockage of blood flow to the brain?
What is the term used to describe a temporary blockage of blood flow to the brain?
What is the recommended time frame for the full work-up in a stroke unit?
What is the recommended time frame for the full work-up in a stroke unit?
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What is thrombolysis in the context of stroke treatment?
What is thrombolysis in the context of stroke treatment?
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Which of the following is true about the Circle of Willis?
Which of the following is true about the Circle of Willis?
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Which of the following statements best describes a Transient Ischaemic Attack (TIA)?
Which of the following statements best describes a Transient Ischaemic Attack (TIA)?
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Which of the following complications may arise due to raised intracranial pressure in stroke patients?
Which of the following complications may arise due to raised intracranial pressure in stroke patients?
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What is a primary consideration in the acute investigation of stroke patients?
What is a primary consideration in the acute investigation of stroke patients?
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Which risk factor is particularly significant for stroke prevention in younger individuals?
Which risk factor is particularly significant for stroke prevention in younger individuals?
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Study Notes
Stroke Overview
- Stroke is a sudden neurological event of vascular origin.
- Key learning objectives include defining stroke, describing the Circle of Willis and extracranial cerebral circulation, understanding Transient Ischaemic Attack (TIA), causes and types of stroke in various age groups, prevention strategies (including risk factors), acute stroke investigation and management, and the natural history of acute stroke.
Learning Objectives
- Define the term "stroke."
- Describe the Circle of Willis and extracranial cerebral circulation.
- Understand Transient Ischaemic Attack (TIA).
- Know the causes and types of stroke in different age groups.
- Have a basic understanding of stroke prevention and its associated risk factors.
- Understand the principles of investigating and managing acute stroke.
- Understand the natural history of acute stroke.
Stroke Advances
- Stroke units provide rapid assessment (within 3-4 hours).
- Early recognition and neuroimaging are essential.
- Early treatment includes thrombolysis (door-to-needle time < 60 minutes) and clot retrieval.
- Stroke prevention involves managing risk factors.
- Neurorehabilitation and intensive care are crucial.
Stroke Mimics
- Hypoglycemia, mass lesions, seizures, migraines, functional hemiparesis, encephalopathy, toxic/metabolic issues should be considered.
- Disguised strokes (including movement disorders, confusion, and vomiting) should not be overlooked.
Stroke Frequency by Type
- Acute ischemic strokes (including infarction - thromboembolic) account for over 65%.
- Hemorrhages (subarachnoid and intracerebral) make up 12%.
- Transient ischemic attacks (TIAs) comprise approximately 21%.
Stroke Risk Factors
- Vessel Wall: Hypertension, smoking, atherosclerosis, hyperlipidemia, and diabetes
- Vessel Lumen: Embolism (heart disease, cardiac dysfunction, arrhythmias, valvular disease), thrombosis (haematologic disorders, hypercoagulability).
Young Stroke (<50)
- Risk factors for younger patients include previously mentioned issues plus large vessel disease (fibromuscular dysplasia, dissection), migraines, small vessel disease (such as vasculitis, drug-induced, sickle cell anemia, and antiphospholipid syndrome), and congenital heart disease (including complications of valve prolapse, and patent foramen ovale).
Cerebral Autoregulation
- Cerebral blood flow (CBF) maintains adequate oxygen supply.
- Ischemic thresholds occur when mean arterial blood pressure (MAP) exceeds autoregulation limits, causing electrical dysfunction, ion pump failure, and eventual cell death.
Blood Supply to the Brain
- The brain receives blood from the internal carotid and vertebral arteries, which branch into the anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA).
Collateral Blood Supply
- Good collateral circulation can reduce infarct extent.
- Inadequate collateral can lead to massive infarction.
- Thrombus propagation can block collateral circulation.
Multiphase CT Angiography
- Used to evaluate the presence and quality of collateral circulation.
- Different phases illustrate the progress and extent of occlusion.
Stroke Imaging
- Early CT scanning (within 50 minutes) typically excludes hemorrhage but may require extended observation.
- MRI or other specialized modalities can detect ischemic changes earlier.
Alberta Stroke Program Early CT Score
- Standardized neuroimaging evaluation for middle cerebral artery (MCA) involvement and lesion assessment.
Early Ischemic Changes (EIC)
- Ischemic lesions are initially characterized by swelling, sulcal effacement, and hypoattenuation.
- Later, hypodensity and petechial hemorrhage may manifest on imaging.
- The EIC on NCCT are sensitive (50%) within 3 hours post insult. The Posterior Circulation is difficult to assess early.
Stroke Classification
- Atherothrombosis
- Small Vessel Disease
- Cardioembolism
- Other Causes
Middle Cerebral Artery (MCA) Occlusion
- MCA infarcts display acute mass effect.
- Older MCA infarcts may show different characteristics.
Large Artery Atherothrombosis
- Emboli commonly originate from carotid bifurcations and atherosclerotic plaques.
- This includes potential issues like arterial dissections, and fibromuscular dysplasia (FMD).
Cardioembolic Stroke
- Mural thrombus in the left ventricle, patent foramen ovale, valvular heart disease, prosthetic valves, and bacterial endocarditis are potential causes.
Non-Valvular Atrial Fibrillation (AF)
- AF significantly increases stroke risk (paroxysmal, persistent, and permanent).
- Prolonged AF duration correlates with a higher stroke risk.
National Clinical Guideline for Stroke
- Guideline offers recommendations for stroke management in the UK and Ireland.
Thrombolysis & Clot Retrieval
- Time is critical in stroke treatment.
- Thrombolysis and clot retrieval are most effective within 1.5 – 4.5 hours of stroke onset.
Endovascular Treatment
- Endovascular procedures are often used to treat strokes.
- Images show the anatomical and procedural aspects of endovascular therapies
Small Vessel Disease
- Perforating vessels are critical for supplying brain stem regions.
- Collateral circulation is minimal.
- Issues include lacuna infarcts. Imaging findings like wide peri-vascular spaces and white matter infarcts are features.
Intracerebral Hemorrhage (ICH)
- Hypertension, amyloid abnormalities, coagulation deficits, aneurysms, arteriovenous malformations (AVMs), cavernomas, tumours, drugs, and trauma are possible etiologies.
- Note that some ICHs originate from cocaine use.
- A significant portion of ICHs are familial/genetic.
Subarachnoid Hemorrhage (SAH)
- SAH is often due to berry aneurysms - usually congenital with enlargement over time..
- Risk factors include cigarette smoking and hypertension.
- Presentation includes the worst headache of one’s life, potentially leading to coma, rebleeding, or death.
- Clinical diagnostics usually require a CT Scan of the head for confirmation
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Description
This quiz covers essential aspects of stroke, including its definition, the Circle of Willis, and the nature of Transient Ischaemic Attack (TIA). Participants will learn about the various types of stroke, prevention strategies, and the importance of timely assessment and management. Enhance your understanding of acute stroke and its implications for different age groups.
