Carotid Disease - Stroke/TIA Flashcards
Neurological deficit attributed to an acute focal injury of the central nervous system by a vascular cause. Including cerebral infarction, intracerebral haemorrhage and subarachnoid haemorrhage.
Stroke
2 different types of stroke
Ischaemic stroke - 80%
Haemorrhagic stroke - 20%
2 different types of ischaemic stroke
Large vessel occlusion
Small vessel occlusion
2 different types of haemorrhagic stroke
Intracerebral haemorrhage
Subarachnoid haemorrhage
What is ischaemic stroke
A blocked artery to the brain, the damage of which depends on location and time.
What is a transient ischaemic attack?
If the blockage self-resolves within 24 hours.
What is the main role of the parietal lobe?
Processing sensory information and proprioception
What is the main function of the cerebellum?
Muscle co-ordination and balance
What do the middle cerebral arteries supply?
Lateral portions of the frontal, parietal and temporal parts of the brain.
What does the anterior cerebral arteries supply?
Medial portions of the frontal and parietal lobes.
What does the posterior cerebral artery supply?
Occipital lobe and thalamus
What is the function of the circle of willis?
Offers alternative ways for blood to get around obstructions.
How does endothelial cell dysfunction occur?
Something irritates or inflames the tunica intima (inner lining of the artery).
When the tunica intima is damaged what forms?
The damage becomes a site for atherosclerosis, plaque forms obstructing blood flow.
What is a plaque made of?
Build up of fats, cholesterol, proteins, calcium and immune cells.
What is an embolism?
Blood clot breaks off from one location and gets lodged in another.
What causes hyaline atheriosclerosis?
When the blood vessel wall becomes filled with protein.
What does hyaline atheriosclerosis cause?
Hypertension and diabetes due to thickening of the arterial wall and narrowing of the lumen.
What is lacunar stroke?
Stroke involving the deep branches of the middle cerebral artery supplying the basal ganglia. The damaged area of the brain goes on to form cysts that look like lakes.
Shock results in
Reduction in blood flow throughout the body
Shock results in what types of ischaemic stroke?
Watershed infarct
What is the ischaemic core?
The tissue that will likely die at the site of a stroke.
What is the ischaemic penumbra?
The tissue surrounding the ischaemic core that is preserved by collateral circulation. May survive if blood flow is restored quickly.
What does the absence of glucose and oxygen for a cell lead to the build up of?
Na+ and Ca2+
What does a build up of high Na+ levels in a cell cause?
Cytotoxic edema
What is cytotoxic edmea caused by?
Na+ drawing water into the cell making it swell.
What does high levels of Ca2+ in a cell lead to?
Damages lipids in mitochondria and lysosomes causing the cell to release apoptosis inducing factors and degradative enzymes.
What are symptoms often seen with anterior/middle cerebral artery stroke?
Numbness
Sudden muscle weakness
What occurs if a stroke affects broca’s area?
Slurred speech
What occurs if a stroke affects wernicke’s area?
Difficulty understanding speech
What symptom’s are often seen with a posterior cerebral artery stroke.
Problems with vision
FAST
Facial drooping
Arm weakness
Speech difficulties
Time - time to get help
How is the site of stroke located within the brain?
CT Flair MRI Angiography
What are the four causes of ischaemic stroke?
Atherosclerosis Thrombus Embolus Shock (general reduction of blood flow)
Define infarction.
Obstruction of the blood supply to an organ or region of tissue, causing local death of the tissue.
Where do the majority of embolisms that cause large vessel occlusion originate from?
Internal carotid artery