Seizure is the sudden onset of involuntary, uncontrolled movements. Seizures are caused by abnormal electrical activity in the brain . A person who experiences a seizure is often unaware of the occurrence. The person may stop or slow breathing. The person may have urinary or bowel incontinence . It may take a while for the person to regain full consciousness .
Seizures usually last from a few seconds to about 2 minutes. A seizure lasting more than 5 minutes is a serious medical emergency.
Seizures have many causes. A seizure may indicate damage to brain tissue, such as might result from head injury, brain cancer, or a cerebral vascular accident (CVA), also known as a stroke . A high fever , greater than 104 °F (40 °C) body temperature , may cause a febrile seizure. Febrile seizures occur more often among children but can also occur in adults. Other diseases and some medications may also cause seizures. An individual who has two or more seizures that do not result from an infection, injury, tumor, or other known cause may have a brain disorder called epilepsy .
Types.
Medical experts classify seizures into two main groups, called focal seizures and generalized seizures. Focal seizures are caused by abnormal electrical activity in just one lobe of the brain. They are also called partial seizures. Generalized seizures result from abnormal activity occurring over the whole brain at the same time.
A focal seizure can be simple or complex. In both types, uncontrolled movement occurs only in the portion of the body controlled by that region of the brain. A person experiencing a simple focal seizure is aware of the event. In a complex partial seizure, on the other hand, the person experiencing the seizure is unaware of what is happening. This type of seizure may progress into a generalized seizure.
Generalized seizures are classified as tonic-clonic and absence seizures. These are also called grand mal and petit mal seizures. Tonic-clonic seizures begin with a complete stiffening of the body, called the tonic phase. This phase is followed after about a minute by a clonic phase. The clonic phase is characterized by jerking movements of the extremities and chewing movement of the mouth for another minute. After a tonic-clonic seizure, the person may appear unconscious for a time. The length of each phase can vary, and the seizure can repeat for a number of cycles.
An absence seizure is brief, usually lasting only for a few seconds. A person experiencing an absence seizure will become suddenly unaware or their surroundings. The person may still walk and talk but will have no knowledge of what happened. Absence seizures may be accompanied with slight twitching of the fingers or face.
Diagnosis and treatment
of seizures depends on their cause. Doctors may use an electroencephalograph (EEG) to measure and record electrical voltages produced in the brain. A personal monitoring device worn on the wrist can determine if a seizure has occurred and record how many occur over a time.
Medications called anticonvulsants are used to control seizures if they occur frequently. People who have frequent seizures may obtain specially trained service dogs. The dogs can sense when a person about to have a seizure and alert others or lie with the person to help prevent injury. In cases where seizures are frequent and uncontrolled, doctors may perform surgery to remove the part of the brain that causes the seizure. This surgery is more successful in children, whose brains can adapt after the surgery.
If you see someone having a seizure, call for medical help. Try to remember what time the seizure started and how long it lasts. Remove anything from the area that the person might hurt themselves by bumping into. A person having a seizure should be gently placed on his or her side to help breathing and to prevent choking if vomiting occurs. Do not try to hold the person still or prevent movement. Do not put anything into the person’s mouth.
