Definition
Stroke is the sudden loss of one or more functions such as movement, sensation, speech, or perception due to the blockage of the arteries that supply blood to the brain. Different parts of the brain control various functions, and these functions depend on the energy (oxygen and glucose) delivered via the blood carried by arteries. If an artery becomes blocked, the functions of the brain area it supplies may be lost, resulting in a stroke. If the blockage is cleared quickly, the symptoms may be temporary; however, if the blockage lasts beyond a critical period, permanent damage to the brain may occur.