Author: Dr S Andrew Josephson University of California San Francisco 2012-02-20
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 based on the area of the brain involved; sudden weakness and numbness on one side of the body is one common symptom of stroke. If the symptoms completely resolve within 24 hours, the condition is instead termed a transient ischemic attack (TIA).