Seizure

A seizure is a sudden change in behavior due to abnormal electrical activity in the brain. Characteristics of a seizure may include convulsions, sensory disturbances, and a loss of consciousness. Experiencing a seizure does not necessarily mean a person has epilepsy. A seizure may be caused by an infection of the brain, an imbalance of body fluids or chemicals, a severe head injury, or other medical conditions. When a person has experienced a seizure, the doctor will usually order an electroencephalogram, or EEG, to determine the type of seizure experienced.

 

What Is a Seizure?

A seizure is a brief, sudden change in behavior caused by abnormal electrical activity in the brain. When brain cells are not working properly, a person's consciousness, movement, or actions may be altered for a short time. These physical changes are called a seizure. Seizures affect people of all races and nationalities.
 

What Causes a Seizure?

There a can be number of reasons why someone has a seizure. For example, many young children have convulsions from fevers (see Febrile Seizures). These febrile convulsions are one type of seizure.
 
Another type of seizure includes those caused by an imbalance of body fluids or chemicals, such as low blood sugar in diabetics or by alcohol or drug withdrawal.
 
Other possible causes of a seizure may include:
 
  • An infection of the brain
  • Severe head injury
  • Eclampsia
  • Tumor
  • Stroke
  • Other medical conditions.
     

Seizure: Symptoms

Although there are many types of seizures, each with its own symptoms, it is wise to consult a doctor if you experience one or more of these possible symptoms of a seizure:
 
  • Episodes of staring or unexplained periods of unresponsiveness
  • "Blackouts" or periods of confused memory
  • Involuntary movement of arms and legs
  • "Fainting spells" with incontinence (or followed by excessive fatigue)
  • Odd sounds, distorted perceptions, or episodic feelings of fear that cannot be explained.
     

Diagnosing a Seizure

When someone has experienced a seizure, the doctor will usually order an electroencephalogram, or EEG, to determine what type of seizure the person may have had and if there are any detectable abnormalities in the person's brain waves. The doctor also may order brain scans to identify abnormalities that may be visible in the brain.
 
If a person has had two or more seizures, he or she considered to have epilepsy.
 

Seizure Types

There are two general types of seizures:
 
  • Generalized seizures. In a generalized seizure, all brain cells are involved. One type of generalized seizure consists of a convulsion with a complete loss of consciousness. Another type looks like a brief period of fixed staring.
     
  • Partial seizures. A "partial" seizure occurs when the brain cells not working properly are limited to one part of the brain. Such partial seizures may cause periods of "automatic behavior" and altered consciousness. This is typified by purposeful-looking behavior, such as buttoning or unbuttoning a shirt. Such behavior, however, is unconscious, may be repetitive, and is usually not recalled.
     
Written by/reviewed by: Arthur Schoenstadt, MD
Last reviewed by: Arthur Schoenstadt, MD