Stroke Flashcards
Define stroke
‘Cerebrovascular accident’ represents a sudden onset of focal neurological deficit attributed to a vascular cause
Due to infarction of brain tissue due to blockage of blood supply or bleed within the brain
Define TIA
a sudden onset of focal neurological deficit attributed to a vascular cause WITHOUT an infarction of brain tissue = TIA
Temporary blockage in a cerebral vessel - usually resolves within 24 hours
Ischaemic stroke vs haemorrhagic stroke
Embolus/ thrombus - prevents blood from getting to brain tissue - resulting in cell death and infarction - ischaemic
Bleed - reduced blood supply to brain and compression of structures - haemorrhagic
Risk factors for ischaemic stroke - list 7
Diabetes Mellitus Previous TIA/stroke Smoking Thrombophilia Atrial Fibrillation Carotid Artery Stenosis Hypercholesterolemia
Risk factors for haemorrhagic stroke - list 3
Severe, uncontrolled hypertension (>140/90)
AV malformation
Anticoagulation therapy - warfarin (vitamin K antagonist), heparins (enoxaparin, dalteparin), direct thrombin inhibitor (dabigatron) or DOACs (factor Xa inhibitors) such as rivaroxaban and apixaban
Infarcts affecting the frontal lobe may result in what changes?
Personality, mood, speech, behaviour, potentially broca’s aphasia, MOTOR (pre frontal gyrus) contra lateral side
Infarcts affecting the temporal lobe may result in what changes?
Sense of smell, hearing loss, memory loss, agnosia and wernicke’s aphasia (speak, but doesn’t make sense)
Infarcts affecting the parietal lobe may result in what changes?
Sensory loss, visuospatial function, maths, speech and language - may present with contralateral hemispacial neglect
Infarcts affecting the occipital lobe may result in what changes?
Visual field defects (usually a contralateral hemianopia) as primary visual cortex is in the occipital lobe
There will be macular sparing due to collateral blood supply of the macula
… cerebral - motor deficits and sensory deficit in contralateral lower limb and genitals
Anterior cerebral - motor deficits and sensory deficit in contralateral lower limb and genitals
DANISH acronym - cerebellar artery
Dysdiadochokinesia Ataxia Nystagmus Intention tremor Slurred speech Hypotonia
Anterior, middle and posterior cerebral arteries come off from the circle of Willis to supply the brain - they originate from … … artery
Anterior, middle and posterior cerebral arteries come off from the circle of Willis to supply the brain - they originate from internal carotid
… cerebral - motor deficits and sensory in contralateral face and upper limb, homonymous hemianopia due to the optic tract being affected and speech difficulties as brocas and wernickes are in this territory
Middle cerebral - motor deficits and sensory in contralateral face and upper limb, homonymous hemianopia due to the optic tract being affected and speech difficulties as brocas and wernickes are in this territory
… cerebral - homonymous hemianopia with macula sparing and visual agnosia
… artery = can result in DANISH
Posterior cerebral - homonymous hemianopia with macula sparing and visual agnosia
Cerebellar artery = can result in DANISH
BAMFORD/OXFORD stroke classification
Define TACS
All 3 of shown
PACS is … of the TACS criteria
Any 2/3 of the TACS criteria (as shown)
LACS - may present with…
Pure motor symptoms
Pure sensory
Mixed sensori-motor
Ataxia
POCS stroke
Cerebellar dysfunction (DANISH)
Bilateral motor/sensory deficit
LOC
Or homonymous hemianopia
History and exam for stroke
When did it start? Within 6 hours - may be a candidate for thrombectomy
Stroke or stroke mimic such as DKA or migraine with aura, sepsis or space-occupying lesion - determine using NIHSS
Neuro exam - cranial and peripheral
CVS exam - AF, BP, cardiac murmur, carotid bruits
CT head without contrast - no signs = likely TIA
ECG, Echo, bloods, Doppler ultrasound of carotid artery
Management of a TIA
TIA clinic - one stop clinic (OBS, bloods, ECG, Doppler U/S of carotid and MRI brain to look for small infarcts)
Educate patient and carer - stroke association information (Driving info, and other risk factors as shown)
TIA - managing risk factors
TIA - what should be given immediately and continued for about two weeks? Then switch to …
300mg aspirin
Switch to clopidogrel - lifelong
Over 50% obliteration of lumen, vascular surgeons for carotid endarterectomy
Diagnosis of stroke - what to do first?
Secure airway
Provide oxygen
CT confirmation to determine ischaemic or haemorrhagic
Ischaemic stroke management
Ischaemic stroke - 300mg aspirin PO/PR - long term change to anticoagulation
Thrombolysis if <4.5hour since symptom onset, thrombectomy if <6hour since symptom onset
Physio and OT/ SALT teams
Haemorrhagic stroke management
Stop anticoagulation
Call neurosurgeons to refer
Control BP
MDT approach to help - inc PT/OT/SALT
Summary of ischaemic vs haemorrhagic stroke
TIA vs stroke overview
A stroke is a cerebrovascular event that is caused by abnormal … of cerebral tissue.
A stroke is a cerebrovascular event that is caused by abnormal perfusion of cerebral tissue.
Stroke is a common medical emergency that requires urgent recognition and treatment. The total number of strokes each year is estimated at 110,000 and the mortality from a first-ever stroke is 11%. Strokes can broadly be categorised as:
Ischaemic: caused by occlusion of blood vessels, most common accounting for 85% of cases.
Haemorrhagic: result from bleeding, accounts for 15% of cases.
Ischaemic stroke
Ischaemic strokes are due to occlusion of blood vessels that supply the brain parenchyma leading to infarction (tissue necrosis secondary to ischaemia). Ischaemic strokes are common accounting for 85% of all strokes.
Ischaemic strokes are sub-classified according to the Bamford/Oxford classification (discussed below).
Haemorrhagic strokes
Haemorrhagic strokes are the result of bleeding within the brain parenchyma, ventricular system or subarachnoid space. Haemorrhagic strokes account for approximately 15% of all strokes.
They are further divided into an intracerebral haemorrhage (ICH) or subarachnoid haemorrhage (SAH). Due to the different presentation and management, SAH is usually discussed separately.
Ischaemia
Ischaemic strokes are the result of occlusion to cerebral vessels. This can be the result of a thrombus (atheromatous plaque) within a vessel, embolus (blood clot) arising from a distant site, or rarely, dissection.
Thrombosis: local blockage of a vessel due to atherosclerosis. Precipitated by cardiovascular risk factors (e.g. hypertension, smoking) or small vessel disease (e.g. vasculitis, sickle cell).
Emboli: propagation of a blood clot that leads to acute obstruction and ischaemia. Typically due to atrial fibrillation or carotid artery disease.
Dissection: a rare cause of cerebral ischaemia from tearing of the intimal layer of an artery (typically carotid). This leads to an intramural haematoma that compromises cerebral blood flow. May be spontaneous or secondary to trauma.
Haemorrhagic strokes are most commonly due to …. Other causes of non-traumatic intracerebral haemorrhage include vascular malformations (e.g. arteriovenous malformation, ateriovenous fistula), brain tumour, vasculitis or bleeding disorders, among others. Trauma is another major cause of intracerebral haemorrhage but is usually classified as part of traumatic brain injuries.
Haemorrhagic strokes are most commonly due to hypertension. Other causes of non-traumatic intracerebral haemorrhage include vascular malformations (e.g. arteriovenous malformation, ateriovenous fistula), brain tumour, vasculitis or bleeding disorders, among others. Trauma is another major cause of intracerebral haemorrhage but is usually classified as part of traumatic brain injuries.
Risk factors for stroke relate to conditions that affect the integrity of vessels or increase the risk of embolisation.
List..
Smoking Diabetes mellitus Hypertension Hypercholesterolaemia Obesity Atrial fibrillation Carotid artery disease Age Thrombophilic disorders (e.g. antiphospholipid syndrome) Sickle cell disease
The network of blood vessels that supply the brain are joined by the …
The network of blood vessels that supply the brain are joined by the circle of Willis.
Many blood vessels supply different areas of the brain. These are broadly divided into the anterior and posterior circulation.
Anterior circulation: a network of blood vessels arising from the carotid arteries.
Posterior circulation: a network of blood vessels arising from the vertebrobasilar arteries.
Cerebral arteries
There are three major cerebral vessels, which are connected by communicating arteries at the circle of Willis.
Anterior cerebral artery: supplies part of the frontal and parietal lobe. Part of the anterior circulation of the brain
Middle cerebral artery: supplies a large proportion of the lateral surface of each brain hemisphere including the internal capsule and basal ganglia. Most common site of infarction. Forms part of the anterior circulation of the brain
Posterior cerebral artery: supplies the occipital lobe and inferior proportion of the temporal lobe as well as some deep structures (e.g. thalamus). Forms part of the posterior circulation of the brain
There are three major cerebral vessels, which are connected by communicating arteries at the circle of Willis.
List the territories below
The circle of Willis is an arterial polygon and is the main arterial blood supply to the brain. It connects the anterior and posterior cerebral circulation, which arise from the carotid and vertebrobasilar systems, respectively.
Carotid system: the common carotid artery gives off the internal and external carotid arteries. The internal carotid artery is vital to the circle of Willis. It gives off the anterior and middle cerebral arteries as well as the posterior communicating artery.
Vertebrobasilar system: the two vertebral arteries join to form the basilar artery. Multiple branches arise from this artery. The basilar artery gives off the posterior cerebral arteries and joins anterior circulation via the posterior communicating artery.
the common carotid artery gives off the internal and external carotid arteries. The … carotid artery is vital to the circle of Willis. It gives off the anterior and middle cerebral arteries as well as the posterior communicating artery.
the common carotid artery gives off the internal and external carotid arteries. The internal carotid artery is vital to the circle of Willis. It gives off the anterior and middle cerebral arteries as well as the posterior communicating artery.
the two vertebral arteries join to form the … artery. Multiple branches arise from this artery. The … artery gives off the posterior cerebral arteries and joins anterior circulation via the posterior communicating artery.
the two vertebral arteries join to form the basilar artery. Multiple branches arise from this artery. The basilar artery gives off the posterior cerebral arteries and joins anterior circulation via the posterior communicating artery.
The … classification is used to subclassify ischaemic strokes.
The Bamford/Oxford classification is used to subclassify ischaemic strokes.
Bamford/Oxford classification
The Bamford/Oxford classification is used to subclassify ischaemic strokes.
Patients with a haemorrhagic stroke are more likely to present with … features such as …
Global features e.g.
Headache Altered mental status Nausea & Vomiting Hypertension Seizures Focal neurological deficits (dependent on location of bleed)
Patients with anterior ischaemic strokes (i.e. TACS, PACS, LACS) develop a constellation of features dependent on the extent and location of the infarct.
LIST 3
Unilateral weakness and/or sensory deficit: face and/or arms and/or legs
Homonymous hemianopia: visual field loss on the same side of both eyes
Higher cerebral dysfunction: dysphasia, visuospatial dysfunction (e.g. neglect, agnosia)
The cortical … - areas of the body that correspond to the motor and sensory cortex
The cortical homunculus - areas of the body that correspond to the motor and sensory cortex
The posterior circulation is composed of the vertebrobasilar arterial system. This supplies the brainstem, cerebellum and occipital cortex. Therefore, posterior strokes can affect …, …, and cranial nerves. POCS account for 20-25% of ischaemic strokes.
The posterior circulation is composed of the vertebrobasilar arterial system. This supplies the brainstem, cerebellum and occipital cortex. Therefore, posterior strokes can affect balance, vision, and cranial nerves. POCS account for 20-25% of ischaemic strokes.
Posterior ischaemic stroke
Symptoms (6)
Dizziness Diplopia Dysarthria & Dysphagia Ataxia Visual Field defects Brainstem syndromes: often seen with crossed signs*
Posterior stroke syndromes - what is this?
A collection of syndromes that occur due to infarction of specific posterior circulation arteries.
Posterior stroke syndromes
Commonly referred to as ‘brainstem syndromes’. Classical examples include ‘Wallenberg syndrome’ (posterior inferior cerebellar artery occlusion) or ‘locked-in syndrome’ (basilar artery occlusion).
Wallenberg syndrome, also known as lateral medullary syndrome due to its location, presents with a constellation of features: (7)
Nystagmus Vertigo Ipsilateral Horner’s syndrome Ipsilateral facial sensory loss Dysarthria & dysphagia Diplopia Contralateral pain and temperature loss
‘locked-in syndrome’ (… artery occlusion).
‘locked-in syndrome’ (basilar artery occlusion).
Any patient with a suspected stroke on clinical assessment should be…
Any patient with a suspected stroke on clinical assessment should be referred urgently to a stroke unit.
Stroke is initially a clinical diagnosis based on the history and examination. The ‘… test’ is used in the community to quickly screen patients who require urgent transfer to a hyperacute stroke unit (HASU).
Stroke is initially a clinical diagnosis based on the history and examination. The ‘FAST test’ is used in the community to quickly screen patients who require urgent transfer to a hyperacute stroke unit (HASU).
In hospital, patients are assessed using the NIHSS score (see below) in correlation with urgent cross-sectional imaging (i.e. CT head +/- CT angiography). Patients outside the thrombolysis/thrombectomy window may be assessed locally, as appropriate, before transfer to a stroke centre.
Clinical assessment in suspected stroke:
Onset & duration of symptoms: collateral history may be needed
Associated symptoms: headache, vomiting, syncope, seizures (if witnessed)
Neurological deficit: see clinical features
Cardiovascular risk factors: hypertension, diabetes, smoking, high cholesterol, family history
Co-morbidities: heart disease, atrial fibrillation, carotid disease, previous stroke/TIA
Anticoagulation history
Contraindications to thrombolysis or thrombectomy
In hospital, patients are assessed using the … score in correlation with urgent cross-sectional imaging (i.e. CT head +/- CT angiography).
In hospital, patients are assessed using the NIHSS score (see below) in correlation with urgent cross-sectional imaging (i.e. CT head +/- CT angiography).
The Face Arm Speech Time test (FAST test)
A rapid diagnostic screen to assess for features of TIA/stroke used in the community. Anyone with a positive screen should be assessed urgently at a stroke unit. The test is positive if any of the following are met:
New facial weakness
New arm weakness
New speech difficulty
Numerous conditions can present similarly to stroke, which are collectively referred to as ‘stroke mimics’.
List 6 differential diagnosis
Toxic/metabolic: hypoglycaemia, drug and alcohol consumption
Neurological: seizure, migraine, Bell’s palsy
Space occupying lesion: tumour, haematoma
Infection: meningitis/encephalitis, systemic infection with ‘decompensation’ of old stroke
Syncope: extremely uncommon presentation of TIA, many other causes
Non-organic: functional neurological disorders (FND)
The NIH Stroke Scale (NIHSS) is a scoring system out of …, which has been designed as a predictive score of clinical outcome in stroke.
The NIH Stroke Scale (NIHSS) is a scoring system out of 42, which has been designed as a predictive score of clinical outcome in stroke.
The NIH Stroke Scale (NIHSS) is a scoring system out of 42, which has been designed as a predictive score of clinical outcome in stroke.
A score < 4 is associated with a good clinical outcome. A high score (> …) indicates a significant proportion of the brain is affected by ischaemia, and as such, there is higher risk of cerebral haemorrhage with thrombolysis. A score ≥ … is often considered a contraindication to thrombolysis.
A score < 4 is associated with a good clinical outcome. A high score (> 22) indicates a significant proportion of the brain is affected by ischaemia, and as such, there is higher risk of cerebral haemorrhage with thrombolysis. A score ≥ 26 is often considered a contraindication to thrombolysis.
… … is the key investigation in patients presenting with a suspected stroke.
CT head is the key investigation in patients presenting with a suspected stroke.
A CT head is very sensitive for detecting cerebral haemorrhage. In an ischaemic stroke, CT imaging is often normal in the first few hours. Therefore, a normal CT head in the presence of neurological symptoms is presumed secondary to ischaemia.
A CT head is very sensitive for detecting cerebral haemorrhage. In an ischaemic stroke, CT imaging is often normal in the first few hours. Therefore, a normal CT head in the presence of neurological symptoms is presumed secondary to ischaemia.
Investigations for stroke
Bedside: observations, blood glucose, ECG (AF)
Bloods: FBC, U&Es, Bone profile, LFT, ESR, coagulation, lipid profile, HbA1c
Imaging: CT head +/- CT angiography +/- MRI head
Special: Echocardiography, carotid dopplers, 24 hour tape, young stroke screen
Thrombolysis and … have revolutionised the management of stroke.
Thrombolysis and thrombectomy have revolutionised the management of stroke.
The first step in acute management is to determine whether the stroke is … or … on the initial CT.
The first step in acute management is to determine whether the stroke is haemorrhagic or ischaemic on the initial CT.
Haemorrhagic stroke management
Management depends on the extent of bleeding and the suitability for neurosurgical interventions (e.g. co-morbidities, frailty). In most small bleeds, there is no requirement for neurosurgical intervention.
Neurosurgical intervention may be required for larger bleeds with significant neurological deterioration. This includes use of decompressive hemicraniectomy in those meeting specific clinical criteria or suboccipital craniotomy for posterior fossa bleeds.
Ischaemic stroke management
If the CT head does not reveal any signs of intracerebral bleeding then the patient is managed as an ischaemic stroke. An initial decision is made about suitability of thrombolysis based on stroke severity, contraindications and timeframe.
Thrombolysis: synthetic tissue plasminogen activator (e.g. Alteplase). ‘Clot-busting’ drug
Contraindications: checklist (e.g. neurosurgery last 3 months, active internal bleeding, etc)
NIH stroke scale: consider if score ≥ 5 and < 26
Timeframe: within 4.5 hours (‘thrombolysis window’). Limited benefit beyond this time with increased bleeding risk
Thrombolysis: synthetic tissue plasminogen activator (e.g. …). ‘Clot-busting’ drug
Thrombolysis: synthetic tissue plasminogen activator (e.g. Alteplase). ‘Clot-busting’ drug
Contraindications to thrombolysis: checklist (e.g. … last 3 months, active … bleeding, etc)
Contraindications: checklist (e.g. neurosurgery last 3 months, active internal bleeding, etc)
NIH stroke scale: consider thrombolysis if score ≥ 5 and < …
NIH stroke scale: consider thrombolysis if score ≥ 5 and < 26
Timeframe: within … hours (‘thrombolysis window’). Limited benefit beyond this time with increased bleeding risk
Timeframe: within 4.5 hours (‘thrombolysis window’). Limited benefit beyond this time with increased bleeding risk
If thrombolysis is not appropriate in ischaemic stroke, patients should be started immediately on … mg of aspirin for two weeks.
After two weeks, conversion to secondary prophylaxis with … mg clopidogrel is indicated unless anti-coagulation (e.g. NOAC) is appropriate because of aetiology (e.g. AF). If thrombolysis was given, aspirin is usually started 24-48 hours following treatment.
If thrombolysis is not appropriate, patients should be started immediately on 300 mg of aspirin for two weeks. After two weeks, conversion to secondary prophylaxis with 75 mg clopidogrel is indicated unless anti-coagulation (e.g. NOAC) is appropriate because of aetiology (e.g. AF). If thrombolysis was given, aspirin is usually started 24-48 hours following treatment.
If thrombolysis is not appropriate, patients should be started immediately on 300 mg of … for two weeks. After two weeks, conversion to secondary prophylaxis with 75 mg … is indicated unless anti-coagulation (e.g. NOAC) is appropriate because of aetiology (e.g. AF). If thrombolysis was given, aspirin is usually started … hours following treatment.
If thrombolysis is not appropriate, patients should be started immediately on 300 mg of aspirin for two weeks. After two weeks, conversion to secondary prophylaxis with 75 mg clopidogrel is indicated unless anti-coagulation (e.g. NOAC) is appropriate because of aetiology (e.g. AF). If thrombolysis was given, aspirin is usually started 24-48 hours following treatment.
Thrombectomy - what does this involve?
Thrombectomy involves removal of thrombus from a vessel. Mechanical thrombectomy can be completed in specialist centres by the interventional neuroradiology team with the use of special clot retrieval systems. It can be combined with thrombolysis (if not contraindicated and within the licensed time window).
Admission to a … stroke unit for ongoing monitoring is essential.
Admission to a hyperacute stroke unit for ongoing monitoring is essential.
Stroke ongoing management
Blood pressure control: acute control with haemorrhage or peri-thrombolysis. Subsequent treatment if hypertensive emergency, otherwise gradual and cautious introduction of agents.
Blood glucose control: maintain glucose between 4-11 mmol/L. Optimise diabetic control
Anti-lipid therapy: commence on statin 48 hours after the initiation of a stroke unless already established. Avoided in cerebral haemorrhage.
Anti-platelet/anti-coagulation: two weeks of aspirin 300 mg followed by clopidogrel 75 mg daily. Warfarin/direct-acting oral anticoagulant may be appropriate (e.g. AF)
Carotid artery assessment: carotid dopplers or CT angiography. Consider carotid endarterectomy if anterior stroke and significant stenosis (ECST - 70-99% / NASCET - 50-99%).
Swallow and nutrition assessment: complete on all patients. Nil by mouth if unsafe swallow and consider nasogastric tube within 24 hours. SALT/dietician input essential.
Rehabilitation: referral to local stroke unit. All members of MDT essential (PT, OT, SALT, dieticians, social worker, stroke coordinator, neuropsychologist).
Palliative care: early recognition and referral in those with suspected poor outcome
Early complications from stroke (7)
Haemorrhagic transformation of ischaemic stroke Cerebral oedema Seizures Infection (e.g. aspiration pneumonia) Cardiac arrhythmias Venous thromboembolism Death
Late complications from stroke (8)
Mobility & sensory issues Bladder & bowel dysfunction Pain Fatigue Cognitive problems Visual problems Emotional and psychological issues Issues with swallowing, hydration and nutrition
Malignant MCA infarction
Term used to describe rapid neurological deterioration due to cerebral oedema following middle cerebral artery (MCA) territory stroke. May require urgent decompressive hemicraniectomy in selected cases.
It is vital to advise all patients who have had a stroke to stop …
It is vital to advise all patients who have had a stroke to stop driving.
It is vital to advise all patients who have had a stroke to stop driving.
Patients should always be advised to check the DVLA for the most up to date recommendations on driving.
Cars and motorcycles?
Larger vehicles?
Cars and motorcycles: stop driving one month. Inform DVLA if ongoing symptoms after one month Larger vehicles (e.g. buses, lorries): stop driving, inform the DVLA
Stroke is the … leading cause of mortality in the UK.
Stroke is the 4th leading cause of mortality in the UK.
Prognosis of stroke - mortality and disability
Mortality: One in seven patients with acute stroke die in hospital. Mortality following a haemorrhagic stroke is 35-40% higher than ischaemic stroke.
Disability: Around 40% will have difficulty with basic activities of daily living 6 months following their stroke.
