[6] Acute Stroke Flashcards
What is stroke also known as?
Cerebrovascular event
What is a stroke?
A clinical syndrome caused by disruption to the blood supply of the brain
What is a stroke characterised by?
Rapidly developing signs of focal or global disturbance of cerebral functions, lasting for more than 24 hours or leading to death
What is a transient ischaemic attack?
A similar presentation that resolves within 24 hours
What are the 2 types of stroke?
- Ischaemic
- Haemorrhagic
Can ischaemic and haemorrhagic strokes be distinguished clinically?
Not reliably, but there are pointers
What clinical signs point towards a haemorrhagic stroke?
- Meningism
- Severe headache
- Coma within hours
What clinical signs point towards an ischaemic stroke?
- Carotid bruit
- Atrial fibrillation
- Past TIA
What happens in ischaemic stroke?
There is loss of blood supply to part of the brain
After how long does brain tissue cease to function when deprived of oxygen?
60-90 seconds
After how long does brain tissue suffer irreversible injury when deprived of oxygen?
After approx 3 hours
How might atherosclerosis be involved in stroke?
It can disrupt blood supply by narrowing the lumen of blood vessels, leading to a reduction in blood flow
By what methods can atherosclerosis cause the formation of blood clots?
- Due to the reduction in blood flow
- May release showers of small emboli through the disintegration of atherosclerotic plaques
What is an embolic infarction?
When the emboli formed elsewhere in the circulatory system
Where do the emboli typically form in embolic infarction?
- Heart
- Carotid arteries
What can cause embolic infarction originating from the heart?
AF
What happens in an embolic infarction?
The clots enter the cerebral circulation, then lodge in and block brain blood vessels
What are haemorrhagic stroke classified on the basis of?
Their underlying pathologies
Give 5 causes of haemorrhagic strokes
- Hypertensive haemorrhage
- Ruptured aneurysm
- Ruptured AV fistula
- Transformation of prior ischaemic infarction
- Drug-induced bleeding
How do haemorrhagic strokes result in tissue injury?
- Causing compression of tissue from an expanding haematoma(s)
- Blood released by brain haemorrhage appears to have direct toxic effects on brain tissue and vasculature
What might result from compression of brain tissue from a haematoma in haemorrhagic stroke?
It may lead to loss of blood supply to affected tissue, with resulting infarction
What are the causes of stroke in a younger patient?
- Vasculitis
- Thrombophilia
- Subarachnoid haemorrhage
- Venous sinus thrombosis
- Carotid artery dissection
What are the causes of stroke in older patients?
- Thrombosis in situ
- Atherothromboembolism
- Heart emboli
- CNS bleed
- Sudden BP drop
- Vasculitis
- Venous sinus thrombosis
What might cause heart emboli leading to stroke?
- Atrial fibrillation
- Infective endocarditis
- Myocardial infarction
What might cause a CNS bleed leading to stroke?
- Hypertension
- Head injury
- Aneurysm rupture
What sudden BP drop may lead to stroke?
More than 40mmHg
Give an example of a type of vasculitis that can lead to stroke
Giant cell arteritis
What are the risk factors for stroke?
- Hypertension
- Smoking
- Diabetes mellitus
- Heart disease
- Peripheral arterial disease
- Post-TIA
- Polycythaemia vera
- Carotid artery occlusion or carotid bruit
- COCP
- Hyperlipidaemia
- Excess alcohol
- Clotting disorders
What kinds of heart disease increase the risk of stroke?
- Valvular
- Ischaemic
- Atrial fibrillation
What can cause a CNS bleed leading to a stroke?
- Hypertension
- Head injury
- Aneurysm rupture
What sort of vasculitis can lead to a stroke?
Giant cell arteritis
What two ways do strokes typically present?
- Sudden onset
- Step-wise progression of symptoms over hours
What tool can be used to assess sudden onset symptoms that resemble stroke?
FAST
What are the steps of FAST tool for stroke symptom assessment?
- Face (weakness or asymmetry)
- Arm (weakness)
- Speech (difficulty)
- Time to call 999
What do the symptoms of stroke depend on?
The area of the brain that is affected
What affects the severity and quantity of symptoms of stroke?
How extensive the affected area of brain is
What are some possible symptoms of cerebral hemisphere infarct?
- Contralateral hemiplegia
- Contralateral sensory loss
- Homonymous hemianopia
- Dysphasia
How does the contralateral hemiplegia in a cerebral hemisphere stroke progress?
Flaccid initially then becomes spastic
What are some possible symptoms of a stroke involving posterior circulation ischaemia?
- Motor deficits in any combination of arms and legs up to quadriplegia
- ‘Crossed’ syndromes
- Sensory deficits
- Homonymous hemianopia
- Ataxia, imbalance, unsteadiness or disequilibrium
- Vertigo
- Diplopia
- Dysphagia
- Dysarthria
- Locked in syndrome
What motor deficits can occur in a posterior circulation ischaemia?
- Weakness
- Clumsiness
- Paralysis
What is meant by ‘crossed’ syndromes?
Ipsilateral cranial nerve dysfunction and contralateral long motor or sensory tract dysfunction
What sensory deficits can occur as a result of posterior circulation ischaemia?
Numbness including loss of sensation or parasthesia in any combination of the extremities
What causes a locked in syndrome?
Complete infarction of the pons
What are the features of a locked in syndrome?
- Quadriparesis
- Loss of speech
- Preserved awareness and cognition
- Sometimes preserved eye movements
What are lacunar infarcts?
Small infarcts around the basal ganglia, internal capsule, thalamus and pons
What can lacunar infarcts cause?
- Pure motor
- Pure sensory
- Mixed signs
- Ataxia
What is left intact by a lacunar infarct?
Cognition/consciousness
What is an important symptom that affects a large proportion of stroke patients?
Dysphagia
How is a diagnosis of stroke made?
Clinically with imaging to assist
What modes of imaging can be helpful in assessing a patient who has had a stroke?
- CT scan
- MRI scan
What group of stroke patients is a CT scan recommended in?
Those in the acute phase of the stroke
Which type of stroke is a CT scan very sensitive in diagnosing?
Haemorrhagic stroke in acute stage
How does the appearance of a CT scan progress in a patient with an ischaemic stroke?
Often normal at first but improved accuracy after 6 hours
What is an MRI better than a CT scan at assessing in stroke patients?
The site and extent of ischaemic damage
What proportion of stroke patients is an MRI contra-indicated in?
1/3
What can contra-indicate an MRI scan in a stroke patient?
- Too ill
- Confusion
- Pacemaker
- Other metal
Why may additional studies be needed once a stroke has been diagnosed?
To assess the underlying cause of the acute event
What helps to indicate which test may be useful in identifying underlying cause of a stroke?
- Age
- Comorbidities
- Presentation
What are some common additional tests used to assess for underlying causes of stroke?
- USS/doppler of carotid arteries
- ECG and echo
- Angiogram of cerebral vasculature
- Blood tests
What underlying cause of stroke can be detected by USS of carotid arteries?
Carotid artery stenosis
What underlying cause of stroke can be detected by ECG and echo?
Arrhythmias and resultant clots
What underlying cause of stroke can be detected by angiogram of cerebral vasculature?
Aneurysms and AV malformation
What underlying cause of stroke can be detected by blood tests?
- Hypercholesterolaemia
- Clotting disorders
- Other rare conditions
What are the differentials for acute stroke?
- Hypoglycaemia
- TIA
- CNS tumour
- Subdural bleed
- Todd’s palsy
- Drug overdose
When can a TIA be a differential for a stroke?
In the first 24 hours of symptoms only
What aspects of homeostasis should be restored and/or maintained in all patients with stroke?
- Keeps sats over 95% with O2
- Blood sugar levels
What does the specific management of an acute stroke depend on?
The kind of stroke
What is the aim of definitive therapy for an ischaemic stroke in the first few hours?
Removing the blockage
How can the vessel blockage be removed in an ischaemic stroke?
- Thrombolysis (breaking it down)
- Thrombectomy (mechanical removal)
What drug can be used in thrombolysis?
Alteplase
What is the main benefit of thrombolysis?
It can improve prognosis after the acute stroke
What improves the benefits of thrombolysis?
The earlier it is given
What are the criteria that must be met for thrombolysis to be givne?
- Within 4.5 hours of onset
- Haemorrhage has been excluded
What can happen if haemorrhage has not been excluded or thrombolysis is given after 4.5 hours?
It can worsen the outcomes
What sort of ischaemic stroke is mechanical thrombectomy viable for?
Occlusion of large arteries e.g. middle cerebral artery
How is mechanical thrombectomy performed?
Endovascularly
Besides thrombectomy or thrombolysis, what other treatments can help improve outcomes of ischaemic strokes?
- Decompressive hemicraniotomy
- Anti-platelets
When is a decompressive hemicraniotomy useful in treating an ischaemic stroke?
To reduce pressure due to brain swelling
What causes significant brain swelling in ischaemic stroke?
Strokes affecting large portions of the brain - mainly those in the middle cerebral artery
What criteria should patients meet to be considered for a decompressive hemicraniotomy?
- Aged 60+
- Deficit suggestive of infarction of middle cerebral artery
- Decreased consciousness
- Signs on CT of at least 50% of territory of MCA affected
Within what timeframe should a decompressive hemicraniotomy be performed fro acute stroke?
Within 48 hours
What anti-platelet should all patients with an ischaemic stroke be gien?
Aspirin
How can aspirin be given to post-stroke patients?
- Orally (if not dysphagic)
- Rectally
How long should 300 mg aspirin be continued post-stroke?
2 weeks
What should be initiated after the 2 weeks 300mg aspirin post stroke?
Definitive ant-thrombotic therapy
How can haemorrhagic strokes be managed?
- Supportive therapy
- Active monitoring
- Reversal of any anticoagulation
- Surgical intervention
What parameters should be monitored in patinets that have had a haemorrhagic stroke?
- Consciousness
- Blood sugar
- Oxygenation
- BP
If a previously fit haemorrhagic stroke patient has hydrocephalus what therapy should they be considered for?
Surgical intervention
How can anticoagulated patients who have had a haemorrhagic stroke be reversed?
Combination of prothrombin complex and IV vitamin K
What is the main burden of stroke?
40% of survivors have some degree of functional impairment
What problems should be screened for in stroke patients upon admission to hospital and management be commenced as soon as possible?
- Orientation
- Positioning, moving and handling
- Swallowing
- Transfers
- Pressure area risk
- Continence
- Communication
- Ability to understand
- Nutrition and hydration
How should mobility be managed early after a stroke?
Sit patient on edge of bed and consider standing within the first 3 days
What support should people with a post-stroke disability receive?
- Rehab as an inpatient
- Rehab in the community
What areas of disability can stroke rehabilitation help to address?
- Cognition
- Communication
- Emotional function
- Movment
- Self-care
- Swallowing
- Vision
What cognitive functions should be looked at as part of stroke rehabilitation?
- Memory
- Attention
- Visual neglect
What interventions can be used to improve memory post-stroke?
- Increase awareness of memory deficit
- Enhance learning
- External aids like calendars and diaries
- Environmental prompts
How can attention be improved post-stroke?
Manage the patient’s environment and provide prompts relevant to the functional task
What techniques can be used to help reduce visual neglect post-stroke?
- Brightly coloured lines on the edge of a page
- Auditory cues
Which team of specialists can be helpful in managing communication problems in a person who has had a stroke?
Speech and language therapists (SALT)
How can SALT help to improve communication in a person who has had a stroke?
- Direct impairment based therapy
- Enhance remaining language capabilities
- Teach other methods of communicating
What alternative communication methods can be useful to patients who have had a stroke?
- Gestures
- Writing
- Prompts
- Assistive technology
Who should receive emotional support and education after a stroke?
Patient and their relatives
When should a stroke patient with persisting emotional difficulties be referred to more specialised services?
At 6-month or annual reviews
What types of therapies can be used to improve a patients movement after a stroke?
- Physiotherapy
- Fitness training
- Strength straining
- Repetitive task training
Who is physiotherapy useful for after a stroke?
Those with weakness in their trunk or limbs, sensory disturbances, and balance difficulties
How can people who have had a stroke improve their fitness?
- Encourage physical activity
- Cardio and resistance training started with a physio
Who can be considered for strength training after a stroke?
People with muscle weakness
What sorts of strength training is useful after a stroke?
- Repetition of body weight activities e.g. sit -to-stand
- Weights
- Resistance machines and exercise bikes
What repetitive tasks can be trained in the upper limb?
- Reaching
- Grasping
- Pointing
- Manipulating objects
What repetitive tasks can be trained in the lower limb?
- Sit-to-stand
- Transfers
- Walking
- Using stairs
What type of activities must be looked at when assessing a patients ability to self-care?
Activities of daily living
How can better self care be implemented in a patient post-stroke?
- Encourage attending to neglected side
- Establish dressing routine
- Use equipment
What equipment can help to improve a patient’s ability to self-care after a stroke?
- Chair raiser
- Hoists
- Small aids e.g. long handled sponge
What should be offered to patients with dysphagia after a stroke?
- 3-times a week swallowing therapy
- Ensure adequate mouth care to reduce the risk of aspiration pneumonia
What can swallowing therapy involve for stroke patients?
- Compensatory strategies
- Exercises
- Postural advice
What should be offered to stroke patients with persisting hemianopia?
Eye movement therapy
How can the prevention of stroke be classified?
- Primary prevention
- Secondary prevention
- (Tertiary prevention)
What is primary stroke prevention?
Preventing stroke in someone who has no history of stroke or TIA
What is secondary prevention of stroke?
Preventing another stroke occurring in someone who has a history of stroke or TIA
What are some well-documented modifiable risk factors for stroke?
- Hypertension
- Exposure to cigarette smoke
- Diabetes
- AF
- Dyslipidaemia
- Carotid artery stenosis
- Sickle cell disease
- Post-menopausal hormone therapy
- Poor diet
- Physical inactivity
- Obesity
How can hypertension be modified as a risk factor for stroke?
Should be screened for and treated appropriately
How can smoking be modified as a risk factor for stroke?
Offer support, advice and medication to help cessation
How should AF be modified as a risk factor for stroke?
Assess need for thromboprophylaxis against risk of bleeding
Which patients with AF should be offered oral anticoagulation?
- Those with sinus rhythm not restored within 48 hours of onset
- High risk of recurrence
What suggests a high risk of AF recurrence?
- Structural heart defect
- Prolonged AF ( longer than 12 months)
What mediations can be considered for oral anticoagulation?
Warfarin or DOAC
Who should receive statin therapy for primary prevention of CVD?
Adults who have a 20% or greater 10 year risk of CVD
What dietary advise can help reduce risk of stroke?
- At least 5 fruit and veg per day
- Total fat intake less than 30% of total calories
- Saturated fat less than 10% total calories
- Dietary cholesterol less than 300mg/day
What is the recommended advice to give regarding exercise to reduce stroke risk?
At least 30 mins of moderate intensity exercise at least 5 days a week
How can recommended amount of exercise be achieved more easily?
Incorporate into daily life e.g. brisk walking, cycling etc.
What advice should be given to obese people to reduce risk of stroke?
Advice about achieving and maintaining a healthy weight
What things can put people at increased risk of thromboembolism?
- Large anterior MI
- Left ventricular aneurysm or thrombus
- Paroxysmal tachycardias
- Chronic heart failure
- History of thromboembolic events
- Prosthetic heart valves
- Rheumatic heart disease
- AF
What can be given to patients at increased risk of thromboembolism to reduce the risk of stroke?
Anti-thrombotic treamtent
What measures can be used for the secondary prevention of stroke?
The same as used for primary prevention
What is the standard preventive therapy for atherosclerotic stroke?
Carotid endarterectomy
What is a less invasive alternative for carotid endarterectomy?
Carotid stenting
What is recommended for people with neurological symptoms of acute non-disabling stroke or TIA with carotid stenosis of 50-99%?
- Refer for carotid endarterectomy within one week
- Surgery within maximum of 2 weeks
- Control modifiable risk factors
What are the potential complications of stroke?
- Neurological problems
- Pain
- Psychological disorders
- Cognitive impairment
- Speech and communication difficulties
- Visual impairments and hemianopia
- Bladder and bowel problems
- Swallowing problems
- Malnutrition and dehydration
- Sexual dysfunction
- Difficulties with ADL
- Thromboembolism
- Pneumonia
- Bedsores
What neurological problems can occur following a stroke?
- Balance
- Movement
- Tone
- Sensation
What sorts of pain can result from stroke?
- Neuropathic
- Musculoskeletal
What psychological problems can occur following a stroke?
- Depression
- Anxiety
- Emotionalism
- Disturbed social interaction
- Disinhibition
- Agression
How can stroke affect cognition?
- Attention and concentration problems
- Memory
- Disturbance of spatial awareness
- Disturbance of perception
- Apraxia
- Disturbances of executive functioning
What problems can disturbance of executive functioning post-stroke cause?
Difficulty in planning, organising, initiating and monitoring behaviour
What sorts of speech and communication difficulties can arise due to stroke?
- Dysphasia
- Dysarthria
- Apraxia of speech
What bladder and bowel problems can occur due to stroke?
- Urinary incontinence
- Faecal incontinence
- Constipation
