Strokes Flashcards
What are the 2 types of strokes?
- ischaemic and haemorrhagic stroke
What is a TIA?
It is an ischaemic stroke that has symptoms that resolve within 24 hours
But generally presents for just an hour
What are the 4 lobes of each cortex?
- frontal
- temporal
- parietal
- occipital
What does the frontal lobe control?
- executive function
2. movement
What does the temporal lobe control?
- Hearing
- memory
- facial recognition
- smell languages
What does the parietal lobe control?
sensory information
What does he occipital lobe control?
vision
What does the cerebellum controls?
- balance
2. muscle co-ordination
What does the brainstem control?
- heart rate
- blood pressure
- Breathing
- GIT tract
What is the circle of willis?
It is the circulation in the brain that ensures that the brain always has a secondary supply
How is stroke classification?
According to the oxfordshire community project
- TACS- TOTAL ANTERIOR CIRCULATION SYNDROME
- PACS-PARTIAL ANTERIOR CIRCULATION SYNDROME
- LACS-LACUNAR STROKE
- POCS-POSTERIOR CIRCULATION SYNDROME
What is TACS?
This means that the deep structures have experienced haemorhage or iscahemia as well as cortical infarction
- If it is ischaemic in origin it is frequently caused by the middle cerebral artery
- 90% of patients are dead or dependent 1 year after the stroke
What is PACS?
Also affects the proximal middle cerebral artery but the overlying cortex is spared because of good collateral from the leptomeningeal collaterals
What is LACS?
Usually occur in the basal ganglia and pons and ususally caused by hyalinosis
What is the definition of a stroke?
It is an acute neuronal event that occurs as a result of ischaemic or haemoorhagic event
What is the definition of a stroke?
It is an acute neurological event that occurs as a result of ischaemic or haemoorhagic event
What is the penumbra?
It is when the tissue has neurological fallout but there is still viable tissue
What forms the posterior cerebral artery?
The subclavian artery then the vertrbral and then the basilar artery
What are the causes of haemorrhagic strokes?
- hypertensive bleed
- aneurysms
- tumours
- inherited bleeding disorders
- cerebral amyloid angiopathy in the elderly
What are the causes of Ischaemic strokes?
- artherosclerosis
- cardiac emboli
- small vessel disease-diabetes, smoking, alcohol, hypertension
What is Virchows triad about?
- endothelial injury
- hypercoagubality
- stasis
What are the causes of rare strokes especially in younger patients?
- arteritis: SLE, Takayasus HIV
- carotid and vertebral dissection
- fibromuscular dysplasia
- cancer, pregnancy(hypercoaguable states)
- antiphospholipid syndrome
What are the causes of stroke in young patients?
- Illicit drus like TIK, cocaine, amphetamine,
2.
Where do emboli come from most o the time?
- left atrium and left ventricle
- aorta
- carotid artery
Which arrythmia causes strokes?
Atrial fibrillation
What are the modifiable risk factors of strokes?
- smoking
- diabetes mellitus
- hypertension
- the pill
- alcohol
Which blood vessels are prone to developing lacunar infarcts?
- small vessels from the middle cerebral artery (lenticulo striate vessels)
What is aphasia and how do we test it?
- fluency
- naming-ask to name body parts
- comprehension
- repetition
- reading
What is neglect?
- visual-ask them to draw a clock and draw the numbers
- auditory
- tactile
What is anosognosia?
The denial of being ill
What blood vessels are involved in developing a homonomous hemianopia?
anterior circulatioion or poserior circulation
How do patients with TACS present?
- hemiplegia or severe hemipareiss contralateral to the lesion
- hemanopia contralateral to the cerebral lesion
- higher cerebral function disturbance: aphasia
How do patients with PACS present?
With 2/3 of:
- motor/sensory deficit
- hemianopia
- higher cerebral dysfunction
How does POCS presnet?
- with isolated homonymous hemianopia
- cranial nerve palsy and contralateral motor deficit
- horizontal gaze palsy
- cerebellar dysfunction like nystagmus, vertigo
What are stroke mimics?
- hypoglycaemia
- seizures
- migraine
- conversion syndrome
What special investigtions would you do in stroke patients?
- blood glucose
- blood pressure
- bloods: HIV, RPR, cholesterol, FBC
- Imaging:
ECG, CXR, uncontrasted CT - extra things:
-carotid ultrasound, Transthoracic/transoesophageal echocardiogram
What is the causes of strokes?
- large vessels atheroemboli-atheromatous plaques in the carotid or vetebral arteries which caues narrowing and turbulent flow
- cardioemboli
- small vessel occlusion
What leads to an increased risk of cardiac emboli?
1. dilated cardiomyopathy . infective endocarditis 3. mechanical valve lesions 4. atrial and ventricular thrombi 5.myocardial infarction in the last month
How do you manage acute stroke?
- Confirm patent airway and vital signs
- Give oxyfen 2-4l/minutes via face mask or nasal prongs if SATS <95%
- Monitor ECG for atrial fibrillation for the first 24 hours
- Make sure you don’t give blood pressure lowering agents unless it’s a patient with myocardial infarction, aortic dissection
- Keep patient NPO to prevent aspiration and give 0,9% normal saline if dehydrated
- Check Hb and if <10 give oxygen and investigate cause
- manage hgt
What are the complications of strokes?
- Aspiration and pneumonia cause 15-25% death
- depression
- cardiac dysfunction(myocardial infarction
- brain herniation and increased intracranial pressure
- seizures
- DVT, pulmonary embolism
- pressure sores
- UTI’s
What does the CT scan of ischameic stroke look like?
The white and grey matter become dark and get progressively darker
The hypodensity means that there is irreversible damage
How can we prevent a secondary stroke?
- control the risk factors
- Statin to lower the cholesterol
- warfarin especially in AF
- Antiplatelet agent aspirin 75-150mg/d)
- blood pressure always lowered
- carotid endarcetomy or stent if >70% stenosis of ipsilateral carotid
What are the side effects of using aspirin?
-it causes gastrointestinal haemorrhage and irritation
What are the new drugs we can use to help prevent scondary strokes that do not need monitoring of the INR?
NOACS-Novel oral anticogulants
-can cause left intracranial haemmorhage
What are the causes of TIA?
- cardiac emboliism
- artherothromboembolism from carotid arteries
- hyperviscosity like in polycythemia
What is the differential diagnosis of TIA?
- Hypoglycaemia
- migraine aura
- focal epilepsy
