What are the two types of seizures?
When we talk about “Types of Seizures”, it is absolutely critical to keep our thought process crystal clear.
Repeat after me: There are only two types of seizures.
Yes, only two. The various seizure names that you may have heard: lip-smacking seizures, myoclonic seizures, deja-vu seizures, generalized tonic-clonic seizures – fall into one of these two types.
What is the basis of this division into two types?
These two types are based on how a seizure BEGINS.
- Focal seizure: A focal seizure starts in one part of the brain. The electrical surge caused by the seizure may remain restricted to the part where it starts, OR it may later spread over the entire brain.
- Primary Generalized Seizure: The word “Generalized” means all over. A primary generalized seizure starts all over the brain, all at once. There is a sudden surge of electricity, all over the brain, all at once.
This classification also helps us in selecting the right medication. Certain medications work only for Focal seizures, and giving them to a patient with Primary Generalized seizures can actually worsen his/her condition.
So why are there so many other names for seizures?
The names describe what HAPPENS to the person, when he/she has that type of seizure.
For example, “Gelos” in the Greek language means “Laughter”. Therefore, a “Gelastic seizure” is a seizure in which the person laughs for no reason.
It is really unfortunate that there are so many names of seizures. This multitude of names is a source of confusion for patients, and also for doctors.
Having names does help in describing the symptoms succinctly, but many doctors have now started standardizing the words they use. For example, the International League Against Epielpsy (ILAE) now recommends that certain terms such as “dyscognitive seizures” have become old and should no longer be used.
For our purposes, just remembering the names below will be more than adequate.
What are some names of Focal Seizures?
Although it is impossible to list each and every name for focal seizures ever invented, it is useful to know some of these names.
|Name of the seizure||What happens||Origin of the word|
|Automatisms (e.g. lip-smacking, hand-wringing)||Automatic, half-purposeful movements of body parts||English: From the word “automatic”|
|Dissociative||The patient becomes “dissociated” from reality|
|Deja-vu||An intense feeling of familiarity, as if “this has happened before”.||French: Déjà vu means “Already seen”|
|Jamais-vu||An intense feeling of unfamiliarity e.g. towards your own home or neighbourhood||French: Jamais vu means “Never seen”|
|Hyper-kinetic||Dramtic, violent, flinging movements of the entire body||Greek: Hyper means “too much” & kinein means “movement”|
|Dacrystic||The patient cries||Greek: Dakyron means tear|
Here is a video of a young girl having automatisms. Notice the involuntary right eye blinking, then eye flutter. During this time, the girl also becomes less responsive.
This video has been posted on youtube by Paramedical Services Education Group.
At the other end of the spectrum are hyperkinetic seizures. As described, patients have wild flinging movements of the limbs during these seizures.
Incidentally, hyperkinetic seizures usually start from the front of the brain, and mostly happen at night.
What are some names of Primary Generalized Seizures?
Primary Generalized Seizures – Remember: These are seizures that start all over the brain, all at once.
Name of the seizure
Origin of the word
|Absence (also called petit-mal)||The child blanks out||French: Petit-mal means little-illness, indicating how subtle these seizures are.|
|Atonic||The child suddenly loses all muscle power, and may fall down (A drop-attack)||Greek: Tonos means tension. In atonic seizures, all tension within the muscles is suddenly lost, hence A-tonic or without-tone.|
|Myoclonic||There is a sudden jerk of the body, usually the upper body||Greek: Myo=Muscle & Klonos=violent motion|
|Epileptic Spasms||The child’s entire body stomach and shoulders go into spasm, only for a moment so that the baby suddenly lurches forward.|
Here is a video of a very small absence seizure, posted by a well-informed parent on youtube. Notice how subtle the symptoms are.
These blanking out episodes can happen 100s of times in a day! As a result, the child may lose focus repeatedly. He/she may start doing very poorly in school. Teachers may complain (incorrectly) that he/she has become inattentive!
This is a mis-diagnosis that truly pains my heart. It is so easily treatable!
To ensure that you don’t miss this type of seizure, here is another video. This has been posted by Dr. Rajeev Gupta on youtube.
Infantile spasms are common in tuberous sclerosis. Here is an excellent educational video about infantile spasms posted by the TSC alliance.
Which symptoms can be produced by either kind of seizures?
There are some symptoms – such as stiffening or violent movements of the body – which can be produced by either kind of seizure.
When these symptoms are due to a focal seizure, they start in one part of the body. For example, if the focal seizure starts on the left side of the head, then the right side of the body may start to have jerking movements. Gradually, the seizure may spread all over the brain. When this happens, the entire body starts shaking violently.
On the other hand, a primary generalized seizure starts all over the body at once. Therefore the symptoms (e.g. shaking) are seen all over the body, all at once.
Name of the seizure
Origin of the word
|Tonic||A body part or the entire body stiffens up||Same as above, except here “tonic” actually means “too much tension”|
|Clonic||A body part or the entire body shakes violently||Greek: Klonos means violent motion|
|Tonic – Clonic||Alternate stiffening & violent shaking|
|Drop attacks||The child suddenly drops to the ground, most commonly due to A-tonic seizures. But this can also happen with tonic, myoclonic, myoclonic-astatic and other seizures|
Here is a video of a drop attack, posted by a parent on youtube.
And here is one more, of a child having repeated drop attacks. Again, this has been posted by a parent.
Notice how the child has to wear a helmet – to prevent head injury due to a fall.
Here is a another drop attack, this time due to a myoclonic seizure:
Note: Our knowledge of seizures and epilepsy continues to grow every year. We now know now that in uncommon cases atonic/myoclonic/spasms seizures can have a focal onset. This opens the doors to newer medications and the possibility of surgery for these patients – but to avoid confusion, this area of active is not highlighted in this article.
|Caution: This information is not a substitute for professional care. Do not change your medications/treatment without your doctor's permission.|
Dr. Siddharth Kharkar
Dr. Siddharth Kharkar has been recognized as one of the best neurologists in Mumbai by Outlook India magazine and India today Magazine. He is a board certified (American Board of Psychiatry & Neurology certified) Neurologist.
Dr. Siddharth Kharkar is a Epilepsy specialist in Mumbai & Parkinson's specialist in Mumbai, Maharashtra, India.
He has trained in the best institutions in India, US and UK including KEM hospital in Mumbai, Johns Hopkins University in Baltimore, University of California at San Francisco (UCSF), USA & Kings College in London.