A stroke involves loss of brain functions caused by a loss of blood circulation to areas of the brain. The blockage usually occurs when a clot or piece of atherosclerotic plaque breaks away from another area of the body and lodges within the vasculature of the brain.
Review Date: 6/15/2010 Reviewed By: Daniel B. Hoch, PhD, MD, Assistant Professor of Neurology, Harvard Medical School, Department of Neurology, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
