Epilepsy without seizures: Is this possible?

My 69-year-old sister has just been diagnosed with epilepsy, but she's never had any seizures. How is this possible?

- No name / No state given

Mayo Clinic neurologist Jerry Swanson, M.D., and colleagues answer select questions from readers.

Answer

Epilepsy is a complex brain disorder. Although epilepsy is primarily characterized by seizures, the nature of the seizures can vary depending on the type of seizure and the individual person.

In older adults, especially, seizures tend to be more subtle than in younger people and may appear as brief memory lapses or episodes of confusion. In some cases, seizures may cause little or no change in consciousness. Also, involuntary shaking is a less common feature of seizures in older adults. To someone nearby, a person having this type of seizure may simply appear to be staring into space and be unresponsive for a few seconds.

Although it can occur at any age, the onset of epilepsy is quite common after age 65. So it is possible that your sister only recently developed epilepsy. The good news is that epilepsy can be treated. Appropriate treatment of epilepsy is important because recurrent seizures may put your sister and others at risk of physical harm — for example, if your sister has a seizure while driving and loses control of the car.