Plegia and paresis refer to paralysis or impaired movement. Plegia specifically means complete paralysis, while paresis is a partial loss of movement. There are several types of plegia that affect different parts of the body, such as cardioplegia which paralyzes the heart. A stroke occurs when the blood supply to the brain is interrupted, which can cause plegia or paresis on one or both sides of the body depending on the location and severity of the stroke. Symptoms of a stroke depend on the part of the brain affected and may include headaches or paralysis. Plegia and paresis from strokes can be permanent or temporary.