stroke - clinical aspects Flashcards
What happens every 2 seconds?
Someone in the world will have stroke
One every 5 minutes in the UK alone
What is stroke?
A major cause of disability in survivors
The commonest neurological problem in the UK
A clinical syndrome, not a full diagnosis
What are over 50% of all stroke survivors?
Dependent
What is the largest cause of complex disability in adult?
Stroke
What are the approximate percentages after stroke?
- 14% have moderate disability
- 10% have severe disability
- 12% have very severe disability
What is stroke becoming?
More common
Ageing population
What is the cost to economy/year for stroke?
~ £7 billion
What is the definition of stroke?
Acute focal neurological deficit resulting from vascular disease lasting over 24 hours
What is Transient Ischaemic attack (TIA)?
Acute focal neurological deficit resulting from vascular disease lasting less than 24 hours
What is definition of brain attack?
Acute focal neurological deficit likely to be the result of vascular disease
What will not all brain attacks turn out to be?
- Stroke
2. TIA
What is the outdated term for stroke?
Cerebrovascular accident (CVA)
What are the symptoms suggestive of stroke?
- Sudden (maximal at onset or within seconds to minutes)
- Focal, not generalised (collapse and LOC, ‘‘dizziness’’ are not suggestive of stroke)
- Negative symptoms (loss of function)
- Presence of vascular risk factors: age, hypertension, diabetes, cholesterol, other vascular disease, family history
positive symptom: hearing problems, visual domain: migraine with aura, tremor, jerking
What are the red flags of stroke?
- No clear onset history
- No risk factors
- No imaging abnormality
- Young age
- Seizures
- Unusual headache
What are the 3 questions that a neurologist needs to know to make a full diagnosis?
- Where is the lesion? anatomy
- What is the pathology? pathology
- Why has it happened? mechanism/risk factors
What is the value of a full stroke diagnosis?
- Explanation to patient and carer
- Guides further investigation (e.g. carotid vs vertebrobasilar circulation)
- Prevention of recurrence
- Prognosis
- Effective treatment can be targeted
What are used for acute stroke?
- Aspirin
- Thrombolysis
- Stroke unit care benefits
- Carotid endarterectomy
- Lower blood pressure in cerebral haemorrhage
- Thrombectomy for acute ischaemic stroke
What does making an accurate diagnosis in stroke require?
- Detailed history and examination
- Appropriate test including brain imaging
- Tests to identify the mechanism (extracranial vessels, heart, blood tests, etc)
Which part of the brain is affected in stroke?
- cortical or subcortical (lacunar)
- Left or right
- Anterior (carotid) or posterior (vertebrobasilar)
What is the benefit of localizing the stroke?
- confirms diagnosis
- Guides brain and vessel imaging
- Guides likely cause and tests needed
- Guides prognosis
What are the basic anatomy for stroke?
- Basic vascular supply
- Motor system: cortical vs subcortical
- Basic brainstem anatomy
- Basic hemisphere localization of function
What are the divisions of cerebral circulation?
- MCA
- ACA
- PCA
What does MCA supply?
Lateral hemisphere convexity and underlying cortex/ some of white matter
What does the PCA supply?
Medial temporal lobe, occipital and parietal lobes
What is ACA limited to?
Territory on lateral convexity
What gives rise to MCA?
Carotid supply
What gives rise to bilateral posterior cerebral arteries?
2 vertebral artery
What perforators go up to the basal ganglia?
Lenticulostriate
in the motor system what is medial within the frontal lobe?
Leg area
supplied by anterior cerebral arteries
What comes down in corona radiata of white matter?
Different motor area giving rise to fibres
What will cause extensive motor deficit?
Fibres that are closely packed in the sub cortical region
What crosses in the medulla?
The corticospinal tract
What are uncrossed (ipsilateral)?
Cerebellar deficits
What localizes to the brainstem?
Cranial nerve deficits with crossed long tract signs
What are the characteristics of total middle cerebral artery territory infarction?
- Hemiparesis
- Drowsy
- Hemisensory loss
- Cortical signs
- Visual field loss
- Inattention
- Neglect
What are the characteristics of small deep lacunar infarct (subcortical stroke)?
- Hemiparesis (face, arm and leg)
2. Normal conscious level and no cortical signs
How are lacunes usually defined as?
<1.5cm
What does visual field loss involve?
Optic radiation
What are the characteristic of ischaemic stroke: lower brainstem infarct (DWI)?
- Right tongue weakness (XII)
- Mild left hemiparesis
- Left sided sensory loss
- No cortical signs
What are 80% of stroke due to?
Blockage = ischaemia (loss of blood flow)
What are 20% of stroke due to?
Bleeding within the brain or subarachnoid space
What is an episode of acute neurological dysfunction presumed to be caused by?
Ischaemia or haemorrhage persisting greater or equal to 24 hours or until death
What is the pathological type of stroke?
- Cerebral infarction (ischaemic stroke) - 80%
- Primary intracerebral haemorrhage 15%
- Subarachnoid haemorrhage 5%
Why is brain imaging important in stroke?
- Stroke is a syndrome not a full diagnosis
- Excludes stroke mimics
- Imaging excludes haemorrhage (esp CT)
- Clarify the mechanism of stroke syndrome
- Guide further investigation including vascular imaging
What are risk factors for stroke?
- Hypertension
- Diabetes
- Alcohol
- Smoking
- Obesity
- Lipid Profile
- Haematological
- Others
What are the mechanisms of stroke?
• Large artery-to-artery embolism • Small vessel occlusion or rupture • Macrovascular rupture • Cardiac embolism • Haemodynamic • Other
What are the main causes of ischaemic stroke?
- Embolism
2. In situ thrombosis
Where do embolism come from?
- From the heart (Artrial fibrillation. valvular heart disease, myocardial infarction)
- From the extracranial carotid or vertebrobasilar vessels (atheroma, dissection)
Where do in-situ thrombosis come from?
- Small perforating vessel occlusion (lacunar)
- Large vessel occlusion
- Venous occlusion
What are examples of Embolism
- Thrombus
- Atheromatous material
- Vegetations
What are rare causes of ischaemic stroke?
Dissection • Vasculitis & SLE • Drug induced • Migraine • Meningitis • Endocarditis • Paradoxical embolism • Atrial myxoma • Haemodynamic stroke
What are the symptoms of acute intracerebral haemorrhage?
Bright on CT
- Drowsiness
- Headache
- Hypertension
What cannot be reliably distinguished from infarct without a scan?
Bleed
What are the importance of intracerebral haemorrhage?
About 10-20% of all strokes worldwide1 • Median 1 month case fatality 40%2 • 60%-90% of survivors are dependent2 • Case fatality not improved 1980-20062 • Incidence persists in elderly populations3 • Few effective treatments • Similar or greater effect on disability (DALYs) to ischaemic stroke
What are the rare causes of intracerebral haemorrhage?
Cerebral vasculitis • Cerebral venous thrombosis • Drug abuse – Cocaine – Amphetamine • Cerebral tumours
What are the treatment of acute stroke?
- Drug therapy
- Thrombolysis in selected patients within 3 hours
- Aspirin for ischaemic stroke (48 hours) - Stroke unit care
- Maintaining normal physiology
- Preventing and treating complications
- Rehabiliatation - Prevention of recurrence
Time is brain
Rapid neurological examination Immediate CT scan IV access and send bloods (including INR) Consider thrombolysis
What is the only licensed treatment for acute ischaemic stroke?
- Alteplase (rtPA)
Improves chances of a good functional recovery if given within 4.5 hours
What are the limitations of IV thrombolysis alone?
Narrow therapeutic time window
• Contraindications such as recent surgery, coagulation abnormalities, and a
history of intracranial hemorrhage
