STROKE

 Ischemic injury to the brain, stroke, affects large numbers of Americans. More than 730,000 first time and recurrent strokes occur each year. It is the 3rd leading cause of death in most developed countries, including the U.S. The risk of stroke rises dramatically with age, doubling with each decade after age 35. About 5% of people over age 65 have had at least one stroke Stroke occurs when the blood supply to part to part of the brain is interrupted. The primary blood supply to the brain is through two arteries in the neck, the carotid arteries), which then branch within the brain to multiple arteries each supplying a specific area of the brain. Blood flow through these arteries can be reduced by atherosclerosis ("hardening of the arteries"), or by blood clots ("emboli") that move into and clog artieries of the brain. Even a brief interruption of blood flow can cause decreases in brain function. The symptoms vary with the area of the brain affected and commonly include such problems as changes in speech, vision, level of consciousness, or decreased movement or sensation in a part of the body. If the blood flow is decreased for longer than a few seconds, brain cells in the area are destroyed causing permanent damage to that area of the brain or even death.

  Recent experimental studies have shown that many brain cells survivethe initial ischemic injury and only die later, hours or days later. Research on the mechanism involved in this delayed cell death offers promise for therapeutic interventions to reduce the loss of cells and the functional consequences of stroke. In addition, improved understanding of how the brain "learns" to function again after injury is likely to improve the extent of recovery after stroke.

  Members of the CNIR with research and/or clinical interests focused on stroke include Drs. Faden, Friedman, McGrail, Howard, Kellar, Kozikowski, Liu, Ullman, Wang and Wroblewski.