Stroke Flashcards
(27 cards)
What is a stroke?
A sudden interruption of vascular supply of the brain, disrupting the oxygen supply leading to irreversible tissue damage
What are the two main types of strokes?
- Ischaemic
* Haemorrhagic
What is an ischaemic stroke proportion compared to haemorrhagic stroke?
- 85% ischaemic
* 15% haemorrhagic
What are the subtypes of ischaemic stroke?
- Thrombotic stoke =thrombosis from large vessels e.g. carotid
- Embolic stroke =usually blood clot (can be fat/air) AF most important cause of emboli forming
What are the subtypes of haemorrhagic stroke?
- Intracerebral haemorrhage =bleeding in brain
2. Subarachnoid haemorrhage
What is the difference between a TIA and Stroke?
- Stroke lasts more than 24hours or can lead to death
* TIA symptoms and signs resolve within 24hrs and no apparent signs of infarction on MRI/CT
What are the generic features of a stroke?
- Motor weakness
- Dysphasia
- Swallowing problems
- Visual field defects
- Balance problems
How does a cerebral hemisphere infarct present?
- Contralateral hemiplegia: flaccid then spastic
- Contralateral sensory loss
- Homonymous hemianopia
- Dysphasia
What is the presentation of a brainstem infract?
*Severe symptoms including quadriplegia and locked-in syndrome
What is the formal classification system used for strokes?
Oxford stroke classification also known as Bamford classification
How does the oxford/bamford stroke classification classify?
Based on initial symptom presentation. Indicates area the has infarcted
What criteria should be assessed in the oxford/bamford classification system?
- Unilateral hemiparesis and or hemisensory loss of face arm and legs
- Homonymous hemianopia
- Higher cognitive dysfunction e.g. dysphagia
What is present in a total anterior circulation infract? Caused by what vessels?
Due to middle and anterior cerebral arteries
> All 3 of oxford classification present
What is present in a posterior circulation infarct? Caused by what vessels?
Involves vertebrobasilar arteries
Presents with 1 of following:
- Cerebellar or brainstem syndrome
- Loss of consciousness
- Isolated homonymus hemianopia
What is present in a lacunar infarct? Caused by what vessels?
Small infract involves perforating arteries around the internal capsule, thalamus and basal ganglia
Presents with 1 of:
- Unilateral weakness of face and arm, arm and leg or all three
- Pure sensory stroke
- Ataxic hemiparesis
What is present in a partial anterior circulation infarct?
Smaller arteries of anterior circulation e.g. upper or lower division of middle cerebral artery
Present with 2/3 oxford classification
What are patients who have suffered with haemorrhagic stroke more likely to present with than an ischaemia stroke?
- Decrease in level of consciousness
- headache
- nausea and vomiting
- seizures
What investigations are done in suspected stroke?
- first line non-contrast CT head
* MRI
What is the main treatment of ischaemic stroke?
*Thrombolysis with alteplase given if
>Administered within 4.5hrs of onset of stroke symptoms
>haemorrhage definitevely excluded via imaging
What is the overall management of ischaemic stroke as an FY1?
- A-E assessment + GCS
- Urgent CT head request
- Oxygen/fluid optimised, glycaemic control
- Ischaemic stroke diagnosed = give aspirin 300mg orally or rectally ASAP
- Within 4.5 hours given alteplase
- Consider need for thrombectomy
What are absolute contraindications for thrombolysis?
- Seizure at onset of stroke
- Previous intracranial haemorrhage
- Suspected subarachnoid
- Stroke or traumatic brain injury preceding 3months
- LP preceding 7 day
- Active bleeding
- Pregnancy
- Oesophageal varices
- Uncontrolled hypertension
What is the secondary prevention of a stroke?
1st line: clopidogrel
2nd line: aspirin plus MR dipyridamole
Look at other risk factors and treat:
- AF check
- Cholesterol check -statins
- Blood pressure check
Why is regular antihypertensive withheld in stroke and only given is serious medical issue?
This is because lowering blood pressure too much can potentially compromise collateral blood flow to the affected region, and possibly hasten the time to complete and irreversible tissue infarction
What must stroke patients be screened for before oral intake?
*Assess for dysphagia
