Seizures

Characteristics of seizures (physical events that occur due to a change in electrical activity in the brain) include convulsions and loss of consciousness. In some instances, they can cause temporary abnormal sensations or visual disturbances. Possible causes include a severe head injury, an imbalance of chemicals in the body, and alcohol and drug withdrawal. Two or more seizures are often an indication of epilepsy.

What Are Seizures?

Seizures are episodes that occur when there is a sudden, brief change in electrical activity in the brain. When people experience seizures, their consciousness, movement, or actions may be altered for a short time. They affect people of all races and nationalities.
 

Causes of Seizures

A person can have a seizure for a number of reasons. Some people can experience a seizure and not have epilepsy. For example, many young children have convulsions from fevers (see Febrile Seizures).
 
Other types of seizures include those caused by an imbalance of body fluids or chemicals, such as low blood sugar in people with diabetes, or by alcohol or drug withdrawal.
 
Other causes of seizures may include:
 
  • Severe head injury
  • An infection of the brain
  • Eclampsia
  • Tumor
  • Stroke
  • Certain other medical conditions.
     

Symptoms of Seizures

Although there are many types of seizures, each with its own symptoms, you should consult a healthcare provider if you or a member of your family experiences one or more of these possible symptoms:
 
  • "Blackouts" or periods of confused memory
  • Episodes of staring or unexplained periods of unresponsiveness
  • 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.
     

How Are They Diagnosed?

When someone has experienced a seizure, a healthcare provider will usually order an electroencephalogram, or EEG, to determine what type of seizure the person may have had and whether 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 is often diagnosed with epilepsy.
 

Types of Seizures

There are two general types of seizures: generalized and partial.
 
Seizures can be generalized, meaning that 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.
 
A seizure can be "partial" when those 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 remembered.
 
Written by/reviewed by: Arthur Schoenstadt, MD
Last reviewed by: Arthur Schoenstadt, MD
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