Podcast
Questions and Answers
What is a stroke defined as?
What is emphasized for stroke treatment in terms of timing?
Which of the following is a risk factor associated with stroke prevention?
What are Transient Ischaemic Attacks (TIAs)?
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Which structure is involved in the cerebral circulation relevant to stroke?
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What percentage of all cancers do brain tumours represent?
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What is a major consequence of raised intracranial pressure?
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How do brain tumours differ biologically from other tumours in the body?
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What is a potential consequence of localized cerebral oedema?
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What term refers to the condition characterized by abnormal water accumulation in the brain?
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Study Notes
Stroke Overview
- Stroke is a sudden neurological event of vascular origin.
- Stroke Advances:
- Stroke Units: full work-up within 3-4 hours, early recognition, neuroimaging
- Early Treatment: Thrombolysis (door to needle time <60 minutes) & clot retrieval
- Prevention: Risk factor management
- Neurorehabilitation: Intensive care
Learning Objectives
- Define "stroke"
- Describe the Circle of Willis and extracranial cerebral circulation
- Understand Transient Ischemic Attack (TIA)
- Know stroke causes and types (young/old), including risk factors for prevention
- Understand acute stroke investigation and management principles
- Understand the natural history of acute stroke (covered in Brain Tumors lecture)
Stroke Types
- Acute Ischemic Stroke (65%+):
- Infarction (Thrombo-embolic)
- Hemorrhage (12%):
- Subarachnoid hemorrhage (6.6%)
- Intracerebral hemorrhage (5.1%)
- Transient Ischemic Attack (21%)
Stroke Risk Factors
- Vessel Wall: Hypertension, Smoking, Atherosclerosis, Hyperlipidemia, Diabetes
- Vessel Lumen: Embolism (heart disease, impaired cardiac function, CHD, AFib, LVH, valvular disease), Thrombosis (haematocrit, fibrinogen), Other factors (race, family history, oral contraceptives, obesity)
Young Stroke (<50)
- All above risk factors plus:
- Vessel Wall Disease (large vessel, fibromuscular dysplasia, dissection, migraine)
- Small Vessel Disease (vasculitis, drug-induced, sickle cell anemia, antiphospholipid syndrome)
- Heart Disease (congenital heart disease, complications, valve prolapse, patent foramen ovale)
Cerebral Autoregulation
- Cerebral blood flow (mL/100 gms/min) relationship to mean arterial blood pressure (mmHg)
- Vasodilation with increase in CBV (cerebral blood volume) in metabolically active tissue, isodense swelling
- Ischemic thresholds:
- Electrical function affected, electrical failure complete, ion pump failure, K+ release, failure to clear ECF, cell death
- Penumbra (reversible)
- Infarct core (irreversible)
- Time to reperfusion
Blood Supply to Brain
- Blood supply to brain from different arteries (anterior cerebral artery, middle cerebral artery, posterior cerebral artery, anterior choroidal, posterior communicating artery).
Collateral Blood Supply
- Good collateral - silent occlusion, infarct extent reduced.
- No collateral - massive infarction.
- Collateral is blocked by propagating thrombus, massive infarction.)
- Clot lysis: distal propagation, necrotic brain, soft, breaks down, hemorrhage.
Multiphase CT Angiography
- Good, intermediate, and poor collaterals shown in different phases of the angiography.
Stroke Imaging
- CT Scanning (50 minutes, 3 hours, 25 hours): Excludes hemorrhage but may take 60 minutes + before changes appear on CT, MR will demonstrate ischemic changes in a few minutes.
Alberta Stroke Programme Early CT Score
- MCA only (basal ganglia and corona radiata levels).
- 7 cortical and 3 subcortical regions, normal = 1, involved = 0.
Early Ischemic Changes (EIC)
- Swelling, sulcal effacement, ventricle reduction
- Parenchymal hypoattenuation (loss of differentiation, grey vs white, loss of lentiform nucleus.)
- Parenchymal hypodensity (↓ density < normal white)
- Petechial haemorrhage
- NCCT (sensitivity <50% @ 3 hours, poor evaluation) of posterior circulation.
Stroke Classification
- Atherothrombosis
- Small Vessel Disease
- Cardioembolism
- Other causes
Middle Cerebral Artery Occlusion (MCAO)
- MCA Infarct - acute: Note signs of mass effect.
- Old MCA Infarct (5 years later)
Large Artery Atherothrombosis
- Arterial dissection
- Most emboli originate at carotid bifurcation
- Ulcerated plaque (70% stenosis +)
- Aortic arch
Arterial Dissection
- Symptoms of arterial dissection include: neck pain, headache, visual changes, stroke.
- Fibromuscular Dysplasia (causes arterial dissection.)
Cardioembolic Causes
- Mural thrombus (left ventricle)
- Patent Foramen Ovale (PFO)
- Valvular heart disease (prosthetic valve, endocarditis, atrial myxoma)
Non-Valvular Atrial Fibrillation (AF)
- Risk of stroke (paroxysmal, persistent, permanent AF) and risk factors.
National Clinical Guideline for Stroke (2023)
- UK and Ireland guidelines
Thrombolysis & Clot Retrieval
- Time is brain.
- <1.5 hours: patients do very well
- 1.5-3.0 hours: patients do well
- 3.0-4.5 hours: 1:14 patients do very well.
Endovascular Treatment of Stroke
- Carotid artery (T and L) and MCA (proximal, mid, distal, all M2) are shown.
Small Vessel Disease
- Perforating vessels, end arteries, no collateral, no pressure reduction system.
- Supply critical areas (brain stem.)
- Design fault (Charcot-Bouchard aneurysm).
- Lacunar Infarction (small infarct with devastating consequences).
Ischemic White Change, Wide Peri-Vascular Spaces. Old micro-haemorrhages, Deep white matter infarcts all shown on different MRI scans.
Stroke Neuropathology
- Shows various brain scans/images to explain the pathology/diagnosis.
Intracerebral Hemorrhage
- Hypertension
- Amyloid deficits
- Coagulation deficits
- Aneurysm (AVM), Cavernoma, Tumor
- Drugs (therapeutic and recreational)
- Trauma
- Don't forget the cerebellum and the Neurosurgeon!!
- Check the family history!!
- Don't forget the Venous Sinus!
- Amyloid angiopathy (Most commonly βA4 derived)
- Non-amyloidogenic pathway vs amyloidogenic pathway
- Most commonly ΒA4 derived
Subarachnoid Hemorrhage
- Association with polycystic kidneys.
- Berry (saccular) aneurysm.
- Congenital defect; Progressive enlargement in life.
- Risk factors (cigarettes/hypertension.)
- Outcome of Spontaneous Subarachnoid Hemorrhage:
- The worst headache in my life.
- Death
- Coma or Alert
- Survive, rebleed (4–8 days)
- Death
- Diagnostic approach in Subarachnoid Hemorrhage:
- The worst headache of my life, no neurologic exam.
- Neck stiffness = yes/no --> CT scan/subarachnoid blood/other intracranial pathology.
- Xanthochromia = yes/no --> vessel imaging/angiography (to locate cause/surgery/interventional radiology)
- Case Example: 64M, sudden onset severe headache (3 days), drowsy/mild neck stiffness, no other signs, Non Contrast CT shows SAH & probable ACA aneurysm.
Summary Intracerebral Hemorrhage (ICH)
- Hypertension
- Small vascular malformation (AVM)
- Sympathomimetic drugs (cocaine/amphetamines)
- Cerebral amyloid angiopathy (see Lecture on Alzheimer's disease)
- Anticoagulants + other bleeding disorders
- NB: Intracerebral implies hemorrhage into brain substance and differs from intracranial (which includes ALL intra-cranial hemorrhages).
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Description
This quiz provides a comprehensive overview of stroke, including its types, causes, and management strategies. You will learn about the importance of early treatment, risk factors for prevention, and the principles of acute stroke investigation. Test your knowledge on stroke mechanisms and neurorehabilitation techniques essential for optimal recovery.
