A simple definition of "consciousness" is the ability to respond and to remember. With some kinds of seizures, you will not recall the seizure and may not even know that you have had one. How is this possible? In a way, it's like being asleep or under anesthesia. You don't remember what happens to you or around you in those situations either.

Other people with different seizures are aware that they had a seizure and may be absolutely convinced that they were fully conscious the whole time—when in fact they lost consciousness.

Neurologists describe consciousness during seizures as either "impaired" or "preserved." These two categories are not as clearly separate as you might imagine. The degree of impairment or preservation of consciousness varies from seizure to seizure, even in the same person.

You can describe your seizures more accurately if you ask a family member or friend to test you during a seizure. They should ask you to follow commands such as "Show me your left hand" and "Remember the word yellow." If you can follow the command and remember the word, you can tell the doctor that your consciousness was preserved, at least during the time tested.

If either your ability to respond or your memory is impaired, then your consciousness is considered to be affected. These two factors are not equally important to your functioning, however. For example, during a seizure some people can respond to most commands but later be unable to recall some details of the seizure. In certain cases, people are able to perform complex tasks like operating dangerous equipment safely during a seizure but later they do not remember what happened. Of course, it's a bad idea for people who have uncontrolled seizures to do such dangerous things at all!

On the other hand, some seizures can prevent you from moving voluntarily. You may be unable to speak or raise your hand when asked but you may be able to recall the entire event. In this seizure, you did not have impaired consciousness, but only impaired motor control.