The International League Against Epilepsy has developed new terms to describe and classify seizures. This was done to make the names more accurate, less confusing to the public, and more descriptive of what actually happens. The new terms consider these important areas when describing seizures.
The onset 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.
How are seizures now classified?
There are now three major groups of seizures.
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 different 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 rhythmical 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 complete. 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 you explore other treatment options, such as surgery, devices, dietary therapy, new or add-on seizure medications, or a clinical trial.
An appointment with a neurologist or epilepsy specialist may be needed. An MRI (magnetic resonance imaging) scan to look at the brain and EEG (electroencephalogram) tests to record the electrical activity of the brain can be very helpful tools in diagnosing 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.
When a disorder is defined by a characteristic group of features that usually occur together, it is called a syndrome. These features may include symptoms, which are problems that the person will notice. They also may include signs, which are things that the doctor will find during the examination or with laboratory tests. Doctors and other health care professionals often use syndromes to describe a person’s epilepsy.