Pathology of Cerebrovascular Disease Flashcards
Main blood vessels in the brain (constituents of Circle of Willis)
Internal carotid arteries Anterior communicating artery Anterior cerebral arteries Ophthalmic arteries Anterior choroidal arteries Posterior communicating arteries Superior cerebellar arteries Pontine arteries Basilar artery Anterior inferior cerebellar arteries Vertebral arteries Anterior spinal artery Posterior inferior cerebellar arteries
Major categories of stroke
Transient ischaemic attack
Minor stroke
Disabling stroke
What is a stroke?
Focal neurological deficit due to disruption of its blood supply
Transient ischaemic attack features
symptoms and signs last < 24 hours
Minor stroke features
Symptoms and signs last > 24 hours but with minor neurological deficit
Disabling stroke features
Symptoms and signs last > 24 hours with persisting disability that impairs independence
Causes of thrombotic/embolic events
Pro-thrombotic;
Athersclerosis
Smoking
Diabetes
Source of embolus;
Cardiac arrythmia
Thoracic aortic aneurysm
What is a parenchymal/intracerebral haemorrhage?
Haematoma that generally occurs as a result of head trauma
When might a parenchymal/intracerebral haemorrhage occur suddenly without apparent cause?
In people with weakened blood vessels as a result of long-term hypertension
Causes of parenchymal/intracerebral haemorrhage
Head trauma Long-term hypertension Tumours Anticoagulation Brain lesions
Cerebral blood flow accounts for what percentage of cardiac output? Why is this?
15%, due to high metabolic and input requirement
Ischaemia can lead to
infarction
Is damage to neurones permanent or reversible?
Permanent
Components of Virchow’s triad
Change in vessel wall
Change in blood flow
Change in blood constituents
(pro-thrombotic events)
What does Poiseuille’s law state?
That the flow of fluid is related to the viscosity of the fluid, pressure gradient across the blood vessel and length and diameter of the blood vessel
Causes of ischaemic stroke
Atherosclerosis Thrombosis Embolism Hypotension Arterial spasm following subarachnoid haemorrhage Systemic vascular disease Mechanical compression Venous obstruction
Strokes related to the carotid artery and its cerebral branches are associated with
Focal epilepsy
Contralateral sensory/motor deficit
Psychological deficit
Strokes involving the vertebrobasilar circulation lead to
focal brain stem syndrome
What would be seen in the blood vessels of a patient who had suffered an ischaemic stroke?
Fatty plaques lining the blood vessels
Pathogenesis of haemorrhagic stroke
Rupture of a small artery, usually at a bifurcation, leading to catastrophic haemorrhage
What percentage of strokes are haemorrhagic?
15%
What is intracerebral haemorrhage associated with in people over 50?
Systemic hypertension
Where do haemorrhagic strokes commonly occur?
80% in basal ganglia
The rest in the brainstem, cerebellum and cerebral cortex
Features of haemorrhagic stroke
Rapidly growing intracranial space-occupying lesion and increased intracranial pressure
Brain swelling with a shift in structures due to compression
Cause of subarachnoid haemorrhage
Rupture of a saccular/berry aneurysm on the Circle of Willis
Arteries most commonly affected by subarachnoid haemorrhage
Internal carotid
Anterior communicating
Middle cerebral
How would intraventricular haemorrhage present in premature infants/babies?
Hypoxia
Consequences of intracranial haemorrhage
Death
Clinical features of stroke
Secondary infarction
Loss of brain tissue
