Ischemic Stroke: sudden loss of function resulting from disruption of the blood supply to a part of the brain. Neurons die when they can no longer maintain aerobic respiration.
- Event usually the result of long-standing cerebrovascular disease
- early Tx results in fewer symptoms and less functional loss
5 different types
- large thrombosis – 20%
- small penetrating artery thrombosis – 25%
- cardiogenic embolic stroke – 20%
- cryptogenic 30%
- Other – 5%
Large artery thrombosis strokes: due to atherosclerotic plaques in the large blood vessels of the brain. Thrombus formation and occlusion at the site af the atherosclerosis result in ischemia and infarction.
Small Penetrating artery thrombotic strokes: affect one or more vessels and are the most common type of ischemic stroke.
Aka lacunar strokes because of the cavity that is created once the infarcted brain tissue disintegrates.
Cardiogenic embolic strokes: are associated with cardiac dysrhythmias, usually atrial fibrillation. Emboli originate from the heart and circulate to the cerebral vasculature, most commonly the left middle cerebral artery, resulting in a stroke. Embolic strokes may be prevented by the use of anticoagulation therapy in patients with atrial fibrillation.
The 2 remaining categories of ischemic strokes are cryptogenic with no known cause and others causes such as cocaine, coagulopathies, migraine and spontaneous dissection of the carotid or vertebral arteries.
Martin, Glenn and Porth, Carol, Mattson. 2009. Pathophysiology Concepts of Altered Health States. 8th ed. Lippincott Williams and Wilkins. Philadelphia