Author: Dr S Andrew Josephson University of California San Francisco 2012-02-20
Introduction
Introduction
A stroke is defined as the sudden onset
of a neurologic deficit attributable to a vascular cause. A stroke
results from lack of blood flow to an area of the brain. Without
adequate blood flow, neurons (nerve cells) in the brain will begin to
die. Symptoms of a stroke are variable depending on the area of the
brain involved but can include weakness or numbness on one side of the
body, new problems with vision, dizziness, or severe headache. A stroke
is classified as either (1) ischemic (also termed “cerebrovascular
accident” [CVA]), where an occluded blood vessel deprives an area of the
brain of blood flow
or (2) hemorrhagic (also termed intracerebral hemorrhage [ICH]), where
there is bleeding into the brain tissue itself; approximately 15-20% of
strokes are hemorrhagic in nature and these are the focus of this
review.