A seizure is how your body reacts to a brief electrical disturbance in the brain, which can include a change in sensation, awareness, or behavior. Electrical disturbances that start in a small part of the brain are called partial seizures. They only involve part of the brain and part of the body.

There are two types of partial seizures: simple and complex. A person who has a simple partial seizure stays alert, can answer questions and follow commands. They may also experience unusual sensations or movements. The seizures end quickly, usually lasting for just a few seconds. However, some can last up to 2 minutes. The person remains conscious and alert through the seizure, so he or she can remember what happened before, during and after the episode.

Complex partial seizures involve a change in or loss of consciousness. They may begin with an odd taste or smell, a rising feeling in the stomach, or a sense of déjá vu. The person may not be able to answer questions or follow commands. The person will also generally repeat an activity like chewing, tapping, or clapping the hands. When the seizure subsides, the person will have no memory of the seizure or the repeated activity that took place during the seizure. Also, the person will usually be tired or disoriented for a short period of time (post-ictal period), usually for about 15 minutes but possibly up to 2 hours.

Both kinds of partial seizures can spread to become stronger generalized seizures, which involve a much larger portion of the brain. These are called "secondary generalized seizures" and generally last less than 2 minutes. Partial seizures can happen to anyone of any age, but more typically occur in people who have had a head injury, brain infection, stroke, or brain tumor. However, the cause is usually unknown.