Stroke
A sudden blockage of one or more major arteries supplying the brain, usually coused by a blood clot (or fragment) carried with the blood stream gets stuck as the artery gradually narrows. The symptoms of a stroke are sudden loss of muscle strength, feeling, speech, vision and other functions in organs controlled by the affected part of the brain. Patients may also become unconscious or die if the affected part of the brain is large enough or controls vital organs. If treated immediately (some) function may be restored, but the more time that passes before treatment is started, the less chance of recovery.
GE Healthcare Glossary