Pathology of Cerebro-Vascular Disease Flashcards
What is the cause of a stroke?
Interruption of supply of oxygen and nutrients causing damage to brain tissue
What can changes can cause interruption of supply of oxygen?
Vessel wall, blood flow and blood constituents
What are the 3 main causes of localised interruption of blood supply?
Atheroma and thrombosis - ischaemia
Thromboembolism - ischaemia
Ruptured aneurysm - haemorrhage
What does internal carotid artery thrombosis typically cause?
Ischaemia in middle cerebral artery territory
Describe the pathogenesis of ischaemia stroke
Brain is very sensitive to oxygen ischaemia
Can lead to infarction - damage to neurons is permanent and they do not regenerate
Describe a regional cerebral infarct
Localised area of brain death
Classically wedge shaped reflecting arterial perfusion territory
Soft then becomes cystic
Describe the histology of an infarct
Loss of neurons causing clinical functional deficit
Microglia are brain macrophages that eat up dead tissue - repair process leading to gliosis (CNS fibrosis)
What is a common place for ruptured vessel wall?
Cerebral arteries - have thin walls which can weaken and hypertension can cause aneurysm to form
What does ruptured vessel cause?
Haemorrhage with possible distal ischaemia due to spasm of entry
What are 2 common areas of ruptured vessels causing haemorrhagic strokes?
Basal ganglia - microaneurysms form in hypertensive patients
Circle of Willis - berry aneurysm in hypertensive patient
What causes generalised interrupted blood supply or hypoxia?
Low O2 in blood - CO poisoning, near drowning and resp. arrest
Inadequate supply of blood - cardiac arrest, hypotension, brain swelling
What are zones of infarction at interface of artery perfusion territories called?
Water shed infarcts - zone is poorly perfused
What does pure hypotension with oxygenated blood cause?
Watershed infarcts
What does complete loss of perfusion and oxygen cause?
Cortical necrosis
