Vitamin E (a-tocopherol) has antioxidant properties which prevent free radical damage to the nervous system, and there is a well-recognized association between vitamin-E deficiency and ataxia. This may result from such causes as malabsorption, the result of intestinal and liver disease, or severe malnutrition. There are also a number of hereditary conditions which can cause this deficiency. The classical abnormalities in fat-soluble vitamin-E deficiency progress from hyporeflexia, ataxia, limitation in upward gaze, and strabismus to long-tract defects, muscle weakness, visual field constriction, and centrocecal scotomata.