Because the condition is not progressive, science does not classify stages of epilepsy. The condition usually first appears in children and teens from between 5 and 20 years old. However, symptoms can begin at any age depending on the cause such as head injury or the presence of another neurological condition. Some underlying causes of epilepsy are progressive, such as AIDs, Alzheimer’s disease and cancerous brain tumors. Although some of these conditions are treatable, epilepsy may continue afterwards depending on how much damage to the brain occurred.