Epilepsy is a neurological disorder characterized by recurrent seizures. These seizures are usually triggered by abnormal brain activity or environmental factors such as stress, anxiety, fatigue, or physical trauma. Epilepsy affects approximately 1% of the population worldwide. People with epilepsy have varying degrees of seizure types (epileptic convulsions versus generalized tonic-clonic seizures). The most common type of epileptic seizure is called a “simple” seizure. Simple seizures occur when there is no abnormality in the brain at all; they are generally caused by a malfunctioning part of the nervous system. A second type of seizure, called a “complex” seizure, involves damage to multiple parts of the brain and results in loss of consciousness. Complex seizures may result from head injuries or other causes such as stroke or infection. Other types include those related to hormonal changes during pregnancy and those that result from certain drugs or alcohol use.
The symptoms of epilepsy vary widely among individuals. Some people experience only minor problems while others develop severe complications. There are many different types of seizures, some of which may cause no obvious signs or symptoms at all. Seizures can affect any part of the body, but they tend to strike younger adults more often than older ones.
The most common types of seizures include:
Absence (petit mal) – Also known as a “black out,” this type of seizure may cause a subtle pause in movement or behavior.
Aura – Affecting only some people with epilepsy, an aura is a sense of dread or physical symptom that alerts a person to an oncoming seizure. Auras occur before a generalized seizure but do not affect the entire body. An aura may be a strange taste, smell, or physical sensation.
Atypical – These seizures are similar to absence seizures in that they affect the awareness and consciousness of an individual but do not cause a total loss of movement or awareness. Atypical seizures can cause repetitive blinking or eye movements, lack of attention to one side of the body or environment, strange sensations, or other problems resulting in behavioral changes.
Cluster – Also known as “pseudoclusters,” these seizures are similar to grand mal seizures except that they occur in groups or clusters. Like grand mal seizures, they cause a loss of consciousness and typically happen without warning.
Febrile – Febrile seizures are convulsions brought on by high fever in children between six months and five years old. These types of seizure are unrelated to epilepsy and will not reoccur in most children as they grow older.
Grand mal (or major) – Also known as “tonic-clonic,” grand mal seizures cause a loss of consciousness and convulsions. These types of seizure typically cause involuntary, jerking movements of the arms and legs. After the convulsions ends there is typically a state of confusion or sleepiness called the “post-ictal” phase.
Petit mal (or minor) – Also known as “absence,” petit mal seizures cause a lapse of attention or unconsciousness of up to twenty seconds. These types of seizure typically begin in childhood and may increase in frequency during teenage years.
Tonic – Also known as “drop attacks,” tonic seizures cause a loss of muscle tone and typically last less than thirty seconds. These types of seizure usually occur in children between the ages of four months and four years old and rarely reoccur in adulthood.
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