Seizures can cause involuntary changes in body movement or function, sensation, awareness, or behavior. A seizure can last from a few seconds to a few minutes. There are more than 20 different types of seizures.

Seizures are often associated with epilepsy and related seizure disorders.

Seizure is often associated with a sudden and involuntary contraction of a group of muscles. However, a seizure can also be as subtle as marching numbness of a part of body, a brief loss of memory, sparkling of flashes, sniffing an unpleasant odor, a strange epigastric sensation or a sensation of fear. Therefore, it is traditional to classify the seizures as motor, sensory, autonomic, emotional and cognitive.

Some seizure types are:

• petit mal seizure (an absence seizure, or very brief loss of consciousness)
• partial (focal) seizure (usually a motor or sensory seizure that is restricted to one side of the body)
• partial complex seizure (characterized by brief loss of consciousness, behavioral, emotional symptoms, loss of memory and automatisms; temporal lobe and frontal lobe seizures are often in this category)
• generalized tonic-clonic seizure (grand mal seizure; motor seizure of both sides of the body)

It is still disputable whether a febrile seizure has to be regarded as an epileptic disorder or not. In general, a patient with two or more episodes of seizures is accepted to have epilepsy (a condition also known as a seizure disorder.) Many people with epilepsy percieve "auras", telltale sensations such as strange lights or unpleasant smells, before their seizures.

Major causes of seizures include head trauma, infection, tumors, metabolic alterations (e.g. low or high blood glucose levels), and as part of the withdrawal symptoms associated with certain classes of addictive drugs, especially sedatives such as barbiturates and benzodiazepines. Many seizures have unknown causes.

Seizures in pregnancy can be a sign of eclampsia.

External links:

• MEDLINEplus: Seizures