Think of a stroke as a “brain attack” – it is an emergency! Because a stroke can damage brain tissue, every minute counts. When symptoms appear call 911 immediately. A stroke occurs when the brain is deprived of the oxygen it needs due to an interruption of its blood supply. Without oxygen brain cells die. The oxygen deprived area of brain tissue is called an infarct. Depending on what area of the brain has been affected, a stroke can cause problems with speech, behavior, thought patterns and memory, and may result in permanent brain damage, disability or death.