Epilepsy is a condition of the brain that causes unpredictable, recurrent seizures.
What happens during a seizure?
The type of symptoms a person has during a seizure depends on where the abnormal electrical activity starts in the brain, where it spreads to in the brain, how fast it spreads through the brain, and how much of the brain is affected. There are different kinds of seizures:
- Focal or partial seizures involve only part of the brain and may be simple or complex in nature. Almost all adults who begin having epilepsy have partial seizures.
- Simple partial seizures, often called the aura or "warning," do not involve any alteration of consciousness. Symptoms may involve a variety of sensations, such as a peculiar odor or taste, visual or auditory experiences, a feeling of having "butterflies in the stomach," or a feeling that patients often say is "hard to describe." Symptoms may also include movements on one side of the body, such as the twitching of a thumb or pulling of a corner of the mouth.
- Complex partial seizures involve the alteration of awareness or loss of consciousness. Common symptoms include changes in emotions and thinking, loss of memory, atypical movements such as smacking of the lips, swallowing movements, unusual vocalizations and verbalizations.
- Secondary generalized seizures start in one area and spread throughout the brain.
- Generalized seizures involve the entire brain at once with excessive electrical activity. The person experiencing a generalized, convulsive seizure (also known as a convulsion or grand mal seizure) falls to the ground unconscious. The body stiffens and then makes jerking movements. Most convulsive seizures actually begin as a partial seizure with a rapid spread of abnormal activity across the brain. Seizures that are generalized from the onset are usually seen in childhood. Generalized seizures may also be non-convulsive. These are known as absence (petit mal) seizures. The person experiencing this type of seizure may appear to be daydreaming or staring blankly. This type of seizure begins and ends within seconds and is most common in children with epilepsy.
- Psychogenic non-epileptic seizures (PNES) are behavioral events that resemble epileptic seizures, but are not caused by electrical disruptions in the brain. EEG testing shows no electrical disturbance associated with typical spells. They are caused by stressful psychological experiences or emotional trauma. Psychogenic non-epileptic seizures (PNES) are commonly misdiagnosed as epilepsy. In comprehensive epilepsy programs they represent 20-80% of referrals. Non-epileptic seizures occur more frequently in women (70%) than in men. Approximately 15% of patients who have nonepileptic seizures have both epileptic and non-epileptic seizures. If you have both types, it is important that you and your family attempt to distinguish between the two. This can be determined while you are being monitored in the Epilepsy Monitoring Unit (EMU).