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Gelastic epilepsy

Gelastic epilepsy is a type of epilepsy in which the seizures are 'gelastic'. Gelastikos is the Greek word for laughter. Gelastic epilepsy is slightly more common in boys than in girls. It is, however, very rare and of every 1,000 children with epilepsy, only one, or at the very most 2, children will have gelastic epilepsy.

The most common areas of the brain which give rise to gelastic seizures are the hypothalamus (a small and extremely important structure deep in the centre of the brain), the temporal lobes and the frontal lobes.

A common cause of gelastic epilepsy is a small tumour in the hypothalamus. This tumour may be either a hamartoma or an astrocytoma. A hamartoma is a benign (non-cancerous) growth made up of an abnormal mixture of cells and tissues normally found in the area of the body where the growth occurs. An astrocytoma is a nervous system tumour that grows from astrocytes. Astrocytes are a type of glial cell. Glial cells are the supporting cells of the nervous system.

The majority of these tumours are benign. This means that they may grow only very slowly, and do not spread to other parts of the brain or body.

If a child has gelastic seizures and precocious puberty (which means that they go into puberty very early, usually under 10 years of age), then it is likely that they will be found to have a hypothalamic hamartoma (a hamartoma in the hypothalamus part of the brain).

It is common for older children who have gelastic epilepsy caused by a hypothalamic hamartoma to also have learning and behavioural problems. These usually get worse in the mid to late teenage years.

Symptoms

Seizures may begin at any age, but usually before 3 or 4 years of age. The seizures usually start with laughter. The laughter is often described as being 'hollow' or 'empty' and not very pleasant. However, sometimes the laughter may sound like a child’s normal laughter except that it is out of place. The laughter occurs suddenly, comes on for no obvious reason, and is usually completely out of place, meaning that nothing funny will have happened to make the child laugh. Sometimes older children may complain of a warning beforehand. The warning may be feeling scared, an abnormal smell or taste, although sometimes they cannot describe exactly what this warning feels like.

The laughter usually lasts less than 30 to 45 seconds and stops suddenly. It may then be followed by signs that are more usually seen in focal seizures. These signs can include eyes and head moving to one or the other side, automatisms (such as lip-smacking, mumbling or fidgeting of the hands), altered awareness and lack of response to people around them. These signs may last for seconds to many minutes and then stop. The child may seem confused and want to sleep.

Children may also have other types of seizures, either immediately after these gelastic seizures or at other times. These include tonic-clonic and atonic seizures.

Diagnosis

A detailed history or description of the child's episodes must be taken from someone who has actually seen them. The episodes of laughter can be confused with behavioural or emotional disorders, including in children with attention difficulties or features of autism. This may therefore delay the diagnosis. This is particularly likely to happen in young children. Sometimes a video, with sound, of the child's episodes may be very helpful. The electroencephalogram (EEG) can show focal and generalised abnormalities (sharp waves, spikes or spike and slow waves). A magnetic resonance imaging (MRI) brain scan should always be done. This is to look for the tumours that might be found in the hypothalamus or for tumours or abnormal areas in the temporal or frontal lobes, called ‘focal cortical dysplasia’. A computed tomography (CT) brain scan may not show very small tumours – so any scans of the brain must be done with MRI.

Treatment

The epilepsy medicines used to treat focal seizures may also be effective in treating gelastic epilepsy. These include carbamazepine (Tegretol), clobazam (Frisium), lamotrigine (Lamictal), lacosamide (Vimpat), levetiracetam (Keppra), oxcarbazepine (Trileptal) and topiramate (Topamax). Unfortunately none of the epilepsy medicines is likely to stop all seizures from happening. Surgery, or, less likely, a special form of radiotherapy, may be possible if a tumour in the hypothalamus (or, less commonly in the temporal or frontal lobes) is found to be the cause of the gelastic epilepsy. These treatments are only available in very few specialist centres in the UK. These centres are called the ‘Children’s Epilepsy Surgery Service’ (CESS).

If a child also has precocious puberty, then this can be treated with hormones or hormone-like medicines. Unfortunately, the learning and behavioural problems rarely respond to medical treatment. They may, however, improve after a surgical or radiotherapy treatment, if the cause is due to a hamartoma. Children will usually need additional input in school and some psychological support to help with their learning and behavioural problems.

Information about treatments for children can be found on the Medicines for Children website.

There may be research studies open that are relevant to this epilepsy syndrome. Your child’s doctor will be able to discuss this with you.

If your child has gelastic seizures caused by a hypothalamic hamartoma, they may have prolonged or repeated seizures. Your child’s doctor will discuss a ‘rescue’ or emergency care plan with you to treat any prolonged or repeated seizures.

Outlook

The gelastic and other types of seizures that often accompany them are often very difficult to control. It is rare for anyone with this type of epilepsy to have their seizures controlled for more than a few weeks or months at a time. The best outcome is usually seen in those children (and adults) who have a benign tumour in the hypothalamus (the hamartoma or astrocytoma) or in a temporal or frontal lobe causing their epilepsy. Successful surgery in these children and adults may improve not just their seizure control but also improve their behavioural and even learning problems.

Support

Contact
Charity for families of disabled children.
Freephone helpline: 0808 808 3555
Website: cafamily.org.uk
Email: info@cafamily.org.uk

What is a syndrome?

A syndrome is a group of signs and symptoms that, added together, suggest a particular medical condition. In epilepsy, examples of these signs and symptoms would be things like the age at which seizures begin, the type of seizures, whether the child is male or female and whether they have physical or learning disabilities, or both. The results of an electroencephalogram (EEG) are also used to help identify epilepsy syndromes.

If you would like to know more about an epilepsy syndrome, please speak to your doctor. If you would like to know more about epilepsy in general, please contact the Epilepsy Action Helpline.

Code: 
S027.04

Epilepsy Action would like to thank Dr Richard Appleton, consultant paediatric neurologist and honorary professor in paediatric neurology at Alder Hey Children’s Hospital, Liverpool, UK for preparing this information.

 

This information is exempt under the terms of Epilepsy Action's information quality standards.

  • Updated August 2019
    To be reviewed August 2022

Comments: read the 6 comments or add yours

Comments

For information and support for patients, their parents, carers, et al, you are most welcome to join us at the Gelastic Seizure Support Hub. https://www.facebook.com/Gelastic.Seizures

Submitted by George Helon on

My 2 year old has had febrile seizures from 10 months. Two episodes of complex febrile seizures (3 seizures in 10 hours and then 5 seizures in 7 hours). He also has myoclonic jerks during high temps. He has had one tonic clonic seizure without temperature. All 15 seizures have been tonic clonic, and under 5 minutes, apart from one which (I think) was an abesnt seizure where he just went very stiff and I struggled to get him out of his car seat and into the recovery position as a result.
I've heard this empty laughing in his sleep (always in his sleep) about 7 times. I put the first few down to dreams, although it seemed very strange laughter.
He's done this nearly every night for the past three or four days and I started to get a bit concerned. I've since looked up gelastic seizures on you tube and it sounds very much like that type of laughter on those videos.
He has already had a 20 min EEG which didn't capture anything (he had an "absent episode" during that time) and has had an MRI, genetics and urine analysis.
MRI came back ok. No structural issues. Genetics came back with indication of a protein depletion on a chromosome which the geneticists want to talk to us about but otherwise nothing else came of those results.
I'm wondering if the MRI came back ok, could it still be gelastic seizures? And what I need to do now?

Submitted by Bethan on

Hi Bethan

That sounds like an upsetting situation for you. I can see this is linked from the gelastic epilepsy page. As you can see, it implies that the MRI would show up any tumours. And also that the seizures tend to be focal rather than the tonic-clonic ones your son is experiencing.

Hopefully the meeting with the geneticist will give you some clearer information about what is happening for your son. We’re not medically trained so are not in a position to give you any further information. But I would certainly make sure you have all your questions with you for the meeting with the geneticist.

I do hope you get some clarity soon.

Regards

Cherry  

Epilepsy Action Helpline Team

 

Submitted by Cherry-Epilepsy... on

Hi! I am providing a made up name to protect my family's privacy. My 3 year old son(about to be 4) was recently diagnosed with gelastic seizures. However, when his MRI was done, there was no HH(hypothalamic hamartoma) and his brain was said to be normal ie no abnormalities. The neurologist prescribed Keppra to reduce or prevent occurrences of the seizures, however the medicine does not seem to work. My questions: 1) If a patient has gelastic seizures and does not have HH, what could be the cause for those seizures? 2) Is there any medicine that works to decrease or prevent recurrences of gelastic seizures when the root cause is not HH? Thanks a ton! I never realised how truly rare these type of seizures are. For my son, he just laughs inappropriately for up to 5 or 8 seconds and loses mild control of his hands during the event. He has memory of the event and is also able to somewhat talk through the event. I hope this raises awareness of gelastic seizures. Thank you!
Rustie

Submitted by Rustie Shackleford on

Hi Rustie

That does sound like a confusing and worrying situation for you.

As our information mentions, it is possible to have gelastic epilepsy without having an hypothalamic hamartoma (HH). The epileptic activity can also be found in the temporal or frontal lobes.

Also the fact that the Keppra isn’t working for your son may either mean that he has yet to reach a dose that is likely to control his seizures. Or that it isn’t the right epilepsy medicine for him.

As you can see from our webpage, there are a number of possible epilepsy medicines to try. But the treatment paragraph also says that it can be difficult to control seizures when someone has gelastic epilepsy.

I hope this information is helpful for you. And that things settle down for your son soon.

Regards

Cherry  

Epilepsy Action Helpline Team

Submitted by rich on

Hi! Thanks for the reply. We went for a follow up appointment. And the Doctor as the Neurologist's office says that we should not be calling them gelastic seizures but focal seizures. I am not a Doctor, but i am inclined to believe that if my son is having laughter like seizures, they are gelastic in nature and hence are gelastic seizures. They also said that he may not be getting the dosage that would be effective to treat his seizures and to be patient as they increase it gradually. I somehow think that there may be a better medicine out there that would work much better for him. Thanks so much for having a dialogue with me about this. I am hoping that together we would raise awareness to these seizures.

Submitted by Rustie on

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