Cerebral or brain ischemia occurs when there is not enough blood flow to the brain. This reduction in blood flow restricts oxygen to the brain and may result in dead brain tissue, cerebral infarction or stroke, according to the Columbia University Medical Center.
Brain ischemia may be categorized as focal ischemia or global ischemia, and the cause for ischemia can range from congenital heart defects to sickle cell anemia. Focal ischemia is isolated to a particular region of the brain and occurs when a brain vessel is blocked by the formation of a blood clot. Focal ischemia is generally caused by embolism or thrombosis. Global ischemia covers wide portions of the brain and occurs when blood flow to the brain is severely reduced or stopped. Global ischemia is often the result of cardiac arrest, and if left untreated for too long, may result in severe brain damage, explains the Columbia University Medical Center.
Common symptoms of brain ischemia include weakness in the body, coordination problems, blindness, unconsciousness and speech impairments. In severe cases, brain ischemia may result in irreversible brain damage, stroke or cardiac arrest. Treatments for brain ischemia include alteplase to minimize the effects of ischemic strokes and anticonvulsants for the prevention of seizures, states the Columbia University Medical Center.