Syndrome…injury. Alzheimer's is the progressive neurodegeneration of the bairn cells hence regulating to a condition called dementia (memory loss). Stroke is the sudden brain damage and ocures when a partucualr region of the brain’s oxygen supply, through the blood capialrries, is cut off as a resualt of, for example, a blood clot in the brain, or when the bairn harmoragges.