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What is Epilepsy?

Epilepsy is one of the world's oldest recognized conditions. Fear, miscommunication, discrimination, and stigma have been associated with epilepsy for centuries. Though epilepsy is not a visible condition, it is in fact quite common. There are roughly 3.4 million people with epilepsy in the U.S. which is 3 million adults and 470,000 children as part of the 50 million diagnosed worldwide. 

Epilepsy is a brain disorder that causes recurring, unprovoked seizures in people of all ages. Your doctor may diagnose you with epilepsy if you have two unprovoked seizures or one unprovoked seizure with a high risk of more. Not all seizures are the result of epilepsy. Seizures may relate to a brain injury or a family trait, but often the cause is completely unknown. The word "epilepsy" simply means the same thing as "seizure disorders." It does not state anything about the cause of the person's seizures or their severity.

Depending on a person's triggers, frequency, and type of seizures determines the majority of what their journey with epilepsy can be like. Describing what ones seizures are like is the first step towards a diagnosis.

The new terms to consider when describing seizures.

  • The onset or beginning of a seizure: Where seizures start in the brain tells a lot about what may occur during a seizure, what other conditions or symptoms may be seen, how they may affect someone and, most importantly, what treatment may be best for that seizure type. When we don’t know the onset of a seizure, the wrong treatment may be used. Or a person may not be offered a treatment that has the best chance of helping.

  • A person’s level of awareness during a seizure: Whether a person is aware or not tells a lot about the type of seizure. It’s also very important to know for a person’s safety.

  • Whether movements happen during a seizure: Seizures can also be described by whether motor symptoms occur. When no motor symptoms happen, it can be called a non-motor seizure. This level of description does not need to be used all the time, especially when generally describing or talking about seizures. Yet other times you may find the motor terms helpful.

The circumstances of these factors help determine which classification of seizures a person has. These classifications are split up into three groups and have many specific types of seizures within them. These help narrow diagnosis and provide some clarity during the diagnosis process. 

Seizure Classifications

Generalized onset seizures:

These seizures affect both sides of the brain or groups of cells on both sides of the brain at the same time. This term was used before and still includes seizures types like tonic-clonicabsence, or atonic to name a few.

Focal onset seizures:

The term focal is used instead of partial to be more accurate when talking about where seizures begin. Focal seizures can start in one area or group of cells in one side of the brain.

  • Focal Onset Aware Seizures: When a person is awake and aware during a seizure, it’s called a focal aware seizure. This used to be called a simple partial seizure.

  • Focal Onset Impaired Awareness: When a person is confused or their awareness is affected in some way during a focal seizure, it’s called a focal impaired awareness seizure. This used to be called a complex partial seizure.

Unknown onset seizures:

When the beginning of a seizure is not known, it’s now called an unknown onset seizure. A seizure could also be called an unknown onset if it’s not witnessed or seen by anyone, for example when seizures happen at night or in a person who lives alone.

  • As more information is learned, an unknown onset seizure may later be diagnosed as a focal or generalized seizure.

How are symptoms during a seizure described?

Many different symptoms happen during a seizure. This new classification separates them simply into groups that involve movement.

For generalized onset seizures:

  • Motor symptoms may include sustained rhythmic jerking movements (clonic), muscles becoming weak or limp (atonic), muscles becoming tense or rigid (tonic), brief muscle twitching (myoclonus), or epileptic spasms (body flexes and extends repeatedly).

  • Non-motor symptoms are usually called absence seizures. These can be typical or atypical absence seizures (staring spells). Absence seizures can also have brief twitches (myoclonus) that can affect a specific part of the body or just the eyelids.

For focal onset seizures:

  • Motor symptoms may also include jerking (clonic), muscles becoming limp or weak (atonic), tense or rigid muscles (tonic), brief muscle twitching (myoclonus), or epileptic spasms. There may also be automatisms or repeated automatic movements, like clapping or rubbing of hands, lip-smacking or chewing, or running.

  • Non-motor symptoms: Examples of symptoms that don’t affect movement could be changes in sensation, emotions, thinking or cognition, autonomic functions (such as gastrointestinal sensations, waves of heat or cold, goosebumps, heart racing, etc.), or lack of movement (called behavior arrest).

For unknown onset seizures:

  • Motor seizures are described as either tonic-clonic or epileptic spasms.

  • Non-motor seizures usually include a behavior arrest. This means that movement stops – the person may just stare and not make any other movements.

What if I don’t know what type of seizures I or my loved one have?

It’s not unusual that a person doesn’t know the type of seizure they have. Often seizures are diagnosed based on descriptions of what an observer has seen. These descriptions may not be fully complete or one can’t tell where a seizure begins from this information.

When seizures are difficult to diagnose or seizure medicines are not working to stop seizures, talk to your doctor or treating health care provider.

  • Seeing an epilepsy specialist or having an evaluation at an epilepsy center can help find out if you are having seizures. Not all events are due to epilepsy.

  • An epilepsy center help you explore other treatment options, such as surgery, devices, dietary therapy, new or add-on seizure medications, or a clinical trial.

  • Having tests like an MRI (magnetic resonance imaging) scan to look at the brain and EEG (electroencephalogram) tests to record the electrical activity of the brain are very helpful to diagnose types of seizures and epilepsy properly.

  • Keep asking questions so you get the right tests and right treatment for your type of seizures and epilepsy.

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