Stroke Flashcards
Draw the Circle of Willis and annotate it
Outline the blood supply of the brain
Cerebrovascular accidents are either:
- Ischaemia or infarction of brain tissue secondary to inadequate blood supply
- Intracranial haemorrhage
What are the causes of ischaemic stroke?
Embolism: an embolus originating somewhere else in the body (e.g. the heart) causes obstruction of a cerebral vessel, resulting in hypoperfusion to the area of the brain the vessel supplies.
Thrombosis: a blood clot forms locally within a cerebral vessel (e.g. due to atherosclerotic plaque rupture).
Systemic hypoperfusion: blood supply to the entire brain is reduced secondary to systemic hypotension (e.g. cardiac arrest).
Cerebral venous sinus thrombosis: blood clots form in the veins that drain the brain, resulting in venous congestion and tissue hypoxia
In which ways may cerebral blood flow be disrupted?
- Thrombus formation or embolus, for example in patients with atrial fibrillation
- Atherosclerosis
- Shock
- Vasculitis
What is a TIA?
transient neurological dysfunction secondary to ischaemia without infarction
What is a crescendo TIA?
A crescendo TIA is where there are two or more TIAs within a week. This carries a high risk of developing in to a stroke.
How does stroke normally present?
In neurology, suspect a vascular cause where there is a sudden onset of neurological symptoms.
Stoke symptoms are typically asymmetrical:
- Sudden weakness of limbs
- Sudden facial weakness
- Sudden onset dysphasia (speech disturbance)
- Sudden onset visual or sensory loss
Outline the risk factors for stroke
- Cardiovascular disease such as angina, myocardial infarction and peripheral vascular disease
- Previous stroke or TIA
- Atrial fibrillation
- Carotid artery disease
- Hypertension
- Diabetes
- Smoking
- Vasculitis
- Thrombophilia
- Combined contraceptive pill
What is the ROSIER tool?
Recognition of stroke in emerggency room (ROSIER) is a clinical scoring tool based on clinical features and duration. Stroke is likely if the patient scores anything above 0.
Outline some important differential diagnoses of a stroke
• Migraine
• Epilepsy
• Structural brain lesions (SDH, Tumour,
abscess)
• Metabolic/toxic disorders (hypoglycemia)
• Vestibular disorders
• Functional weakness
• Demyelination
• Mononeuropathy
What are some important features to delineate within a stroke history?
- Onset
- Course
- Focal vs general symptoms
- “Negative” symptoms (loss of function)
+ risk factors
What are 3 important considerations when thinking of thrombolysis?
- Clear time of onset (less than 4 ½ h)
- No contra-indications
- Infarct v haemorrhage
How quickly should patients get a CT scan of their brain?
Within 1 hour
What indications are there for an urgent scan?
Urgent scan if:
• Thrombolysis or early anticoagulation being considered
• On anticoagulant treatment
• A known bleeding tendency
• Depressed level of consciousness (GCS < 13)
• Unexplained progressive or fluctuating symptoms
• Papilloedema, neck stiffness or fever
• Severe headache at onset
How is stroke managed?
- Admit patients to a specialist stroke centre
- Exclude hypoglycaemia
- Immediate CT brain to exclude primary intracerebral haemorrhage
- Aspirin 300mg stat (after the CT) and continued for 2 weeks
- Thrombolysis with alteplase
- Thrombectomy
Outline thrombolysis with alteplase
Thrombolysis with alteplase can be used after the CT brain scan has excluded an intracranial haemorrhage. Alteplase is a tissue plasminogen activator that rapidly breaks down clots and can reverse the effects of a stroke if given in time. It is given based on local protocols by an experienced physician. It needs to be given within a defined window of opportunity, for example 4.5 hours. Patients need monitoring for post thrombolysis complications such as intracranial or systemic haemorrhage. This includes using repeated CT scans of the brain.
List the absolute and relative contraindications to thrombolysis
Outline thrombectomy
Thrombectomy (mechanical removal of the clot) may be offered if an occlusion is confirmed on imaging, depending on the location and the time since the symptoms started. It is not used after 24 hours since the onset of symptoms.
How is TIA managed?
Start aspirin 300mg daily. Start secondary prevention measures for cardiovascular disease. They should be referred and seen within 24 hours by a stroke specialist.
Outline the ABCD2 score
Outline the secondary prevention of stroke
- Aspirin 300mg for 2 weeks, then clopidogrel 75 mg (most patients) or warfarin/NOAC if in AF or cardiac origin of embolism
- Atorvastatin 80mg should be started but not immediately (even if cholesterol is “normal”)
- Carotid endarterectomy or stenting in patients with carotid artery disease
- Treat modifiable risk factors such as hypertension and diabetes
What specialist imaging is available?
- Diffusion-weighted MRI is the gold standard imaging technique. CT is an alternative.
- Carotid ultrasound can be used to assess for carotid stenosis. Endarterectomy to remove plaques or carotid stenting to widen the lumen should be considered if there is carotid stenosis.
How do we delineate whether the right or left cerebral hemisphere has been affected?
- Crossing of sensory and motor fibres:
- Corticospinal tracts – lower medulla
- Spinothalamic fibres – spinal cord
- Dorsal columns – upper medulla
- The “dominant hemisphere”:
- Language function localises to left hemisphere
- Awareness of body localises to right hemisphere
- Visual pathways:
- Monocular vs homonymous deficits
- Cerebellar and cranial nerve lesions
- Result in ipsilateral deficits
How do we delineate whether it is the anterior or posterior circulation affected?
What are the stroke sub-types? (Bamford classification of stroke)
Anterior Circulation:
- TACS Total anterior circulation syndrome
- PACS Partial anterior circulation syndrome
- LACS Lacunar syndrome
Posterior Circulation:
• POCS Posterior circulation syndrome
What are the features of a TACS?
A total anterior circulation stroke (TACS) is a large cortical stroke affecting the areas of the brain supplied by both the middle and anterior cerebral arteries
1. New higher cerebral dysfunction:
- Dysphasia
- Neglect / visuospatial disorder
2. Hemiparesis / hemisensory loss:
• At least 2 of face / arm / leg
3. Homonymous haemianopia
What are the features of a LACS?
A lacunar stroke (LACS) is a subcortical stroke that occurs secondary to small vessel disease. There is no loss of higher cerebral functions (e.g. dysphasia).
One of the following:
- Pure motor stroke
- Pure sensory stroke
- Sensori-motor stroke
- Ataxic hemiparesis
At least 2 or 3 of face, arm, leg
What are the features of a PACS?
A partial anterior circulation stroke (PACS) is a less severe form of TACS, in which only part of the anterior circulation has been compromised.
2 of 3 components of TACS
Higher disturbance of cerebral function
alone
Restricted motor / sensory loss:
- One limb
- Face + hand, but not whole arm
What are the features of a POCS?
A posterior circulation syndrome (POCS) involves damage to the area of the brain supplied by the posterior circulation (e.g. cerebellum and brainstem).
• Ipsilateral cranial nerve palsy with contralateral
motor/sensory deficit
• Bilateral simultaneous motor/sensory loss
• Cerebellar dysfunction (e.g. vertigo, nystagmus, ataxia)
• Isolated visual field defect (homonymous hemianopia)
List the complications of an acute stroke and how these are prevented
- Pneumonia: Swallow assessment, nurse semi-erect, physiotherapy
- Dehydration: IV fluid or NG feeding if oral intake unsafe or inadequate
- Hypoxaemia: Avoid/treat chest infection, treat heart failure
- Seizures: Avoid metabolic disturbance
- DVT: Intermittent pneumatic compression stockings
- Pressure sores: Frequent turning, special mattress, avoid urinary contamination
- Urinary infection: Avoid catheter – use penile sheath
- Constipation: Diet, laxatives
- Painful shoulder: Correct handling, physiotherapy
What investigations should be performed to delineate how a stroke happened?
- FBP & ESR
- U&E (LFT, CK, TFTs)
- Fasting lipids and glucose / HbA1c
- ECG
- Carotid duplex imaging if anterior circulation
- ECHO/Holter – if cardiac embolism suspected*
- CTA/MRA if dissection suspected*
*consultant request
Outline the causes of haemorrhage (age and location)
According to age:
- < 45 years Vascular abnormality, e.g. AVM
- 45–69 years Small vessel disease
- > 70 years Cerebral amyloid angiopathy
Small vessel disease:
- According to location:
- Lobar Amyloid, AVM, small vessel
- Deep white Small vessel disease
List the two types of primary intracranial haemorrhage
- Basal ganglia bleed (due to hypertension)
- Lobar bleed (from cerebral amyloid)
What is Albert’s test?
- Albert’s Test is a screening. tool used to detect the presence of unilateral spatial neglect (USN) in patients with stroke.
- 20% due to haemorrhagic stroke
- Is essentially drawing lines on a page
What is apraxia?
Apraxia is a neurological disorder characterized by the inability to perform learned (familiar) movements on command, even though the command is understood and there is a willingness to perform the movement. Both the desire and the capacity to move are present but the person simply cannot execute the act.
What is neglect?
A tendency to ignore spatial surroundings on
the opposite side to the cerebral damage
What is dysarthria?
Dysarthria is a motor speech disorder in which the muscles that are used to produce speech are damaged, paralyzed, or weakened. The person with dysarthria cannot control their tongue or voice box and may slur words.
What is dysphasia?
- Expressive dysphasia is a difficulty in expressing what you want to say. This may be in the form of speech but may also affect their writing and reading aloud abilities. Speech may be non-fluent, and a person may find it difficult to find the right word for something.
- Receptive dysphasia is when a patient has difficulty with the understanding of written or spoken language. Patients can both hear and see the words but not process and make sense of them.
Outline, again, the Bamford stroke classification
