One of the major causes of nocturnal seizures in adults is autosomal dominant nocturnal frontal lobe epilepsy, states Mayo Clinic. This is a rare genetic condition, but people with a parent that has it have a 50 percent chance of also developing it.
Some other causes of nocturnal seizures in adults include head injuries, brain infections and low blood sugar, states the Sleep Foundation. Drug use and withdrawal from alcohol also cause nocturnal seizures.
A seizure, also known as a convulsion, is a change in the brain's electrical activity that affects behavior, states the Sleep Foundation. A seizure can result in anything from violent shaking of the entire body to a couple of moments of blank staring.