Stroke Flashcards
Name stroke mimics
Seizure (e.g. Todd's palsy following a seizure) Toxic/metabolic Sepsis Dementia Acute confusion Presyncope SOL vestibular dysfunction Functional
What proportion of ‘stroke’ patients who present may be stroke mimics?
1/3
What tool can assess the likelihood of a person having had a stroke when they present with symptoms?
What are the different parts of this tool?
What score makes a stroke likely?
Rosier score Loss of consciousness/syncope (-1 point) Seizure activity (-1 point) New acute onset, or on wakening: - Asymmetric facial weakness (1 point) - Asymmetric arm weakness (1 point) - Asymmetric leg weakness (1 point) - Speech disturbance (1 point) - Visual field defect (1 point) Score >0 makes stroke likely
What are the four stroke syndromes that can present?
Total anterior circulation syndrome (TACS)
Partial anterior circulation syndrome (PACS)
Lacunar syndrome (LACS)
Posterior circulation syndrome (POCS)
What is the most severe type of stroke?
What is the prognosis?
Total anterior circulation syndrome
5% of patients alive and independent at 1year
What are the signs and symptoms of total anterior circulation syndrome?
Hemiplegia involving at least two of face, arm and leg +/- hemisensory loss
Homonymous hemianopia
Cortical signs (Dysphasia, neglect etc)
What are the signs and symptoms of partial anterior circulation syndrome?
2/3 features present in a TACS
or
Isolated cortical dysfunction such as dysphasia
or
pure motor/sensory signs less severe than lacunar syndromes (e.g. monoparesis)
What are lacunar infarcts?
Small infarcts in the deeper parts of the brain (basal ganglia, thalamus, white matter) and brainstem
Caused by occlusion of a single deep penetrating artery
What is effected in a lacunar stroke?
Any two of face arm and leg
What is the prognosis of a lacunar stroke?
60% of patients alive and independent at 1 year
What is the prognosis of PACS?
55% of patients alive and independent at 1 year
What are the signs and symptoms of posterior circulation syndrome?
Cranial nerve palsies Bilateral motor and/or sensory deficits Conjugate eye movement disorders Isolated homonymous hemianopia Cortical blindness Cerebellar deficits without ipsilateral motor/sensory signs (in contrast to ataxic hemiparetic lacunar syndrome)
What major function is often affected by dominant hemisphere cortical events?
Language
What major function is often affected by non-dominant hemisphere cortical events, and what does this lead to?
Spatial awareness
Neglect
What are the causes of stroke?
Atherothromboembolism (50%)
Intracranial small vessel disease (25%)
Cardiac source of embolism (20%)
Rare causes 5%
What are the classes of cerebral small vessel disease?
Type 1: Arteriosclerotic
Type 2: Sporadic and hereditary cerebral amyloid angiopathy
Type 3: Genetic small vessel disease distinct from cerebral amyloid angiopathy
Type 4: Inflammatory and immunologically mediated
Type 5: Venous collagenosis
Type 6: Other small vessel disease e.g. post radiation angiopathy
What is the increased risk of stroke associated with atrial fibrillation?
5 fold increased risk
What proportion of strokes are due to AF?
About 1/6
What type of stroke can be caused by amyloid angiopathy?
Haemorrhagic stroke
What are the classes (and examples for each class) of haemorrhagic stroke?
Primary intracerebral haemorrhage - hypertension - amyloid angiopathy Secondary intracerebral haemorrhage - Arteriovenous malformation - Aneurysm - Tumour
What may a lobar intracerebral haemorrhage be related to?
Cerebral amyloid angiopathy
What may a deep intracerebral haemorrhage be related to?
Effects of hypertension
What four aspects of a stroke should be identified and commented on?
Type of stroke
Size of stroke
Laterality of stroke
Cause of stroke
What does the abcd2 score predict the risk of?
Short term stroke risk after a TIA
Name three antiplatelet drugs
Aspirin
Clopidogrel
Dipyridamole
What is the effect on stroke risk of lowering cholesterol?
It is lowered by 25-33%
What type of stroke is low cholesterol associated with an increased risk of?
Haemorrhagic stroke
What are the principle sites of stenoses in extracerebral arteries?
- Common carotid
- Internal carotid
- Vertebral arteries
- Subclavian arteries
Name some causes of cardio-embolic stroke.
Atrial fibrillation
Valvular disease e.g. congenital valve disorders, infective vegetations, rheumatic and degenerative calcific changes
Mural thrombosis from damaged or akinetic segment of ventricle.
Patent foramen ovale
Which cerebral area is particularly vulnerable to hypoperfusion?
The parieto-occipital area between the middle and posterior cerebral artery territories
Where do most dissections take place that can cause stroke?
Large extracranial neck vessels
What features may be present with a dissection of a neck vessel?
Pain in the neck or face
Horner’s syndrome
Lower cranial nerve palsies
When may venous thrombosis in the intracranial venous sinuses occur?
What may result?
Pregnancy Hypercoagulable states Thrombotic disorders Dehydration Malignancy Results: cortical infarction, seizures, raised ICP
What is the most modifiable stroke risk factor?
What is the relationship between this factor and stroke risk?
Hypertension
There is a linear relationship between blood pressure and stroke risk.
What is CADASIL?
Cerebral dominant arteriopathy with subcortical infarcts and leucoencephalopathy
A rare inherited cause of stroke/vascular dementia.
What investigations should be done in a patient who has had a TIA?
Carotid artery doppler
ECG, echo
CT/MRI brain including angiography
What is often the first clinical evidence of internal carotid artery stenosis?
A TIA causing an episode of amaurosis fugax (sudden transient loss of vision in one eye)
Often a forerunner of hemiparesis.
What are the differential diagnoses of a TIA?
Migraine (headache rare in TIA)
Focal epilepsy (usually recognised by positive features e.g. limb jerking and LOC)
Mass lesion
What is an ischaemic penumbra? How is it detected?
A swollen area surrounding the infarcted area of brain which does not function but is structurally intact.
It is detected on MRI.
It can regain function with neurological recovery.
