Stroke

Question 1

What is a stroke?

Answer 1

Haemorrhagic - burst in a blood vessel,
Ischaemic - caused by atherosclerosis and leads to a blood clot blocking the blood vessels supplying brain.
Transient ischaemic stroke (TIA) - resolved in 24hrs with no major neuro symptoms

Question 2

What is the circle of willis?

Answer 2

A network of blood vessels that supply the brain with blood.
In a circle which allows for compensation if one route is blocked, a stroke occurs when there is a sudden stop in the blood flow.
Internal carotid -> circle of willis
Vertebral -> basilar -> circle of willis.

Question 3

What is the pathophysiology of a stroke?

Answer 3

Reduce in blood flow causes loss of oxygen and glucose. No ATP means NA K pump stops working, NA is retained in cell increasing water potential causing an uptake of water in the cell, leading to cell death/burst. Pro-inflammatory cells like phagocytes lead to inflammation they release pro inflammatory cytokines.

Question 4

What happens in a MCA stroke?

Answer 4

Affects Frontal, Temporal and parietal lobe.
Causes: Contralateral sensory loss
Contralateral motor loss- Muscle weakness, spasticity, hyperreflexia
Dysphagia
Dysarthria
Visual Loss

Question 5

What happens in a PCA stroke?

Answer 5

Affects Occipital, inferior temporal lobe
Causes: Visual field defects
Impairment of memory
Contralateral sensation loss
decreased co-ordination
ataxia
Aphasia - Expressive/receptive
Balance disorders

Question 6

What happens in a ACA stroke?

Answer 6

Affects: Midline of frontal, superior and medial parietal lobe
Causes: Contralateral monoplegia of lower limb
contralateral sensory loss of the lower limb
Urinary incontinence
Behavioural abnormalities