Although epilepsy is often considered a disorder of childhood, it can begin at any age, and in some people it persists from childhood to old age. The rate of newly diagnosed epilepsy is actually higher in elderly people than in middle-aged adults.
As in younger people, the cause of epilepsy that begins in an elderly person cannot be determined in about half of the cases. Of those in whom the cause can be determined, the largest number of cases (about 33%) are caused by stroke, often a small one that did not cause other symptoms. Degenerative disorders such as Alzheimer's disease cause about 11%, tumors (either benign or malignant) lead to about 5%, head injury causes about 2%, and infection gives rise to 1%. Although alcohol abuse is not considered a major cause of epilepsy in the United States, a study in Denmark found that it was very often associated with newly diagnosed epilepsy in adults.
The elderly are more sensitive than younger people to a variety of mental, physical, and environmental stressors. They are also more likely to develop many medical, neurological, and psychiatric disorders, some of which can make seizures more likely to occur. Such disorders include metabolic changes such as very high or very low blood sugar, very low sodium levels, and endocrine disorders (for example, diabetes, thyroid or parathyroid disorders).