Stroke - ischaemic Flashcards
Define what a stroke is
It is rapidly developing clinical symptoms and/or signs of focal (sometimes global) of loss of brain function, with symptoms lasting >24hrs or leading to death due to infarction or haemorrhage (vascular origin)
Define what a TIA is
TIA = transient ischaemic attack or ‘‘mini stroke’’ it is caused by a temporary disruption in the blood supply to part of the brain. Symptoms can be similar to a stroke but symptoms usually last a few mins to hrs and fully resolve within 24hrs
As if they didnt this would be a stroke
What are the 3 main different types of stroke ?
- Infarction
- Haemorrhage
- Subarachnoid haemorrhage
Stroke is subdivided into ischaemic stroke (caused by vascular occlusion or stenosis) and haemorrhagic stroke (caused by vascular rupture, resulting in intraparenchymal and/or subarachnoid haemorrhage)
What is the most common type of stroke ?
- Ischaemic, they account for 85% of strokes
- Haemorrhagic type account for the rest
Define what an ischaemic stroke is due to
It is due to a blood cot forming in an artery leading to the brain or within one of the small vessels deep within the brain, called a cerebral thrombosis
What are the 3 main different types of ischaemic strokes ?
- Cardioembolic - clot blocking artery has travelled to artery it occludes from somewhere more proximal in the arteries or the heart
- Atheroembolic - clot blocking artery formed at the site it is occluding
- Small vessel disease
What are the 2 main types of ischaemic stroke that you need to differentiate between and why ?
Decide if it is a cardioembolic or atheroembolic stroke as the follow up management differs between the two
What are the general signs/symptoms suggestive of stroke ?
Think FAST - facial dropping, arm weakness, speech difficulty, = time to call 999
Some of the symptoms are listed below:
- Sudden numbness or weakness in the face, arm, or leg, especially on one side of the body
- Sudden confusion, trouble speaking, or difficulty understanding speech
- Sudden trouble seeing in one or both eyes
- Sudden trouble walking, dizziness, loss of balance, or lack of coordination
- Sudden severe headache with no known cause
What do the focal signs of a stroke generally depend on ?
The affected artery
What are the 3 vessels which anastomse together to form the circle of willis ?
- The 2 internal carotid arteries
- The basillar artery (formed by joining of the 2 vertebral arteries)
What are the 3 pairs of arteries (as have a R and L part ot the brain) given off by the circle of willis and what do they supply ?
- Anterior cerebral arteries - supplies most midline portions of the frontal lobes and superior medial parietal lobes.
- Middle cerebral arteries - supplies the lateral part of each hemisphere
- Posterior cerebral arteries - supplies the occipital lobe
What are the anterior and middle cerebral arteries branches off ?
The internal carotids
What is are the posterior cerebral arteries branches of ?
The basillar artery
What are the focal signs present in a stroke which could suggest an anterior cerebral artery infarct ?
- Occulsion may cause a weak, numb contralteral leg to the occulsion +/- similar, if milder arm symptoms to the leg again on opposite side to the occlusion. - look out for weakness and sensory loss in contralateral leg
- The face is spared
- Frontal lobe dysfunction e.g. speech
What are the focal signs present in a stroke which could suggest a middle cerebral artery infarct ?
- Note that the MCA supplies the major bulk of the motor and sensory cortex
- Contralateral hemiparesis (weakness of one side of the body)
- Hemisensory loss esp face and arm
- Contralateral homonymous heminopia due to involvement of the optic radiation
- Cognitive change e.g. dysphagia with lesions on dominant side
- +/- Visuo-spatial awareness (cant get dressed and gets lost) with lesions on non-dominant side