When an area of the brain is damaged, which typically occurs with a stroke, an impairment may result. An impairment is the loss of normal function of part of the body. Sometimes, an impairment may result in a disability, or inability to perform an activity in a normal way.
When blood supply is cut off from the brain, cells begin to die from lack of oxygen. Within minutes, skills, such as reasoning, speech, and some degree of arm, leg, or facial movement, may be lost. The type of skills and the amount of loss depend on which part of the brain was affected, and how much tissue was damaged.