Sudden unexpected death in epilepsy (SUDEP) has been defined as occurring in an individual suffering from epilepsy (characterized by recurrent seizures), who dies unexpectedly while in a reasonable state of health, and with death happening suddenly (in minutes), and during normal activities and benign circumstances. Also there should be no obvious medical cause, and death should not be the result of a seizure or status epilepticus, such as inhalation of vomit.

In 1937, Orton described children with motor coordination difficulties as ‘clumsy’, a term still used today. Other terms used to describe these difficulties include developmental dyspraxia, awkwardness, motor learning problems, and most recently, developmental coordination disorder (DCD). DCD is defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) as a ‘marked impairment in the development of motor coordination [that]... interferes with academic achievement or activities of daily living’. The impaired coordination is present in the absence of a known medical condition such as cerebral palsy or muscular dystrophy. The heterogeneity of the motor and cognitive abilities of children included in this classification, and the numerous terms employed to describe them, have hindered systematic accumulation of knowledge about DCD.

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.