Epilepsy is a condition in which a person has recurrent seizures. A seizure is defined as an abnormal, disorderly discharging of the brain’s nerve cells, resulting in a temporary disturbance of motor, sensory, or mental function.
There are many types of seizures, depending primarily on what part of the brain is involved. The term epilepsy says nothing about the type of seizure or cause of the seizure, only that the seizures happen again and again. A stricter definition of the term requires that the seizures have no known underlying cause. This may also be called primary or idiopathic epilepsy.
- Episodes of abnormal electrical activity within the brain result in seizures.
- The specific area of the brain affected by the abnormal electrical activity may result in a particular type of seizure.
- If all areas of the brain are affected by the abnormal electrical activity, a generalized seizure may result. This means that consciousness is lost or impaired. Often all the person’s arms and legs stiffen and then jerk rhythmically.
- One seizure type may evolve into another during the course of the seizure. For example, a seizure may start as a partial, or focal, seizure, involving the face or arm. Then the muscular activity spreads to other areas of the body. In this way, the seizure becomes generalized.
- Seizures caused by high fevers in children are not considered epilepsy. Also see children’s seizures.
Healthy people may have seizures under certain circumstances. If the seizures have a known cause, the condition is referred to as secondary or symptomatic epilepsy. Some of the more common causes include the following:
- Chemical imbalance such as low blood sugar or sodium
- Head injuries
- Certain toxic chemicals or drugs of abuse
- Alcohol withdrawal
- Stroke, including hemorrhage
- Birth injuries
Almost any type of behavior that happens repetitively may represent a seizure.
- Generalized seizures: All areas of the brain (the cortex) are involved in a generalized seizure. Sometimes these are referred to as grand mal seizures.
- To the observer, the person experiencing such a seizure may cry out or make some sound, stiffen for some seconds, then have rhythmic movements of the arms and legs. Often the rhythmic movements slow before stopping.
- Eyes are generally open.
- The person may not appear to be breathing. The person is often breathing deeply after an episode.
- The return to consciousness is gradual and should occur within a few moments.
- Loss of urine is common.
- Often people will be confused briefly after a generalized seizure.
- Partial or focal seizures: Only part of the brain is involved, so only part of the body is affected. Depending on the part of the brain having abnormal electrical activity, symptoms may vary.
- If the part of the brain controlling movement of the hand is involved, for example, then perhaps only the hand may show rhythmic movements or jerking.
- If other areas of the brain are involved, symptoms might include strange sensations or small repetitive movements such as picking at clothes or lip smacking.
- Sometimes the person with a partial seizure appears dazed or confused. This may represent a partial complex seizure. The term “complex” is used by doctors to describe a person who is between being fully alert and unconscious.
- Absence or petit mal seizures: These are most common in childhood.
- Impairment of consciousness is present with the person often staring blankly.
- Repetitive blinking or other small movements may be present.
- Typically, these seizures are brief, lasting only seconds. Some people may have many of these in a day.
- Other seizure types exist particularly in very small children.
When to Seek Medical Care
A first seizure is a reason to visit your doctor or a hospital’s emergency department. For someone with a diagnosed seizure disorder, a change in seizure patterns or more frequent seizures are reasons to see the doctor.
Visits to a hospital’s emergency department are not needed for everyone with a seizure. Some seizures are emergencies, as in the following cases:
- A seizure that continues for more than 5 minutes (call 911)
- Breathing difficulty (call 911)
- Persistent confusion or unconsciousness (call 911)
- Injuries sustained during a seizure
- A first seizure