Gelastic Epilepsy

Epilepsy Action is indebted to Dr Richard Appleton, a Consultant Paediatric Neurologist who specialises in children’s epilepsy, and to Dr Rachel Kneen, Consultant Paediatric Neurologist and Dr Stewart Macleod, Specialist Registrar in paediatric neurology, at Alder Hey at Alder Hey Children’s Hospital, Liverpool, who have kindly prepared the information on this page.

Gelastic epilepsy refers to a type of epilepsy, in which the seizures are 'gelastic', gelastikos being the Greek word for laughter. Gelastic epilepsy is very rare and occurs slightly more commonly in boys than in girls. Of every 1000 children with epilepsy, only one or at the very most, two children will have gelastic epilepsy.

Symptoms

Seizures may begin at any age but usually before three or four years of age. The seizures usually start with laughter and the laughter is often described as being 'hollow' or 'empty' and not very pleasant. The laughter occurs suddenly, comes on for no obvious reason and is usually completely out of place.

Sometimes older children may complain of a warning beforehand, although they are not always able to describe exactly what this warning is like.

The laughter usually lasts less than one minute and is then followed by signs that are more usually recognised with complex partial or focal seizures. These signs can include eye and head moving to one or the other side, automatisms (such as lip-smacking, mumbling or fidgeting of the hands) and altered awareness. This period may last for seconds to many minutes and then stops.

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

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 (also know as drop seizures).

A common cause of gelastic epilepsy is a small tumour in the hypothalamus (area of the brain). These tumours may be either a hamartoma or an astrocytoma. The majority of these tumours are benign (which means that they may grow only very slowly and do not spread to other parts of the brain or body).

If the 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 the child 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 and these usually get worse in the mid to late teenage years.

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 and this may delay the diagnosis. This is particularly likely to happen in young children. Sometimes a video of the child's episodes may also 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 be done to look for the tumours that might be found in the hypothalamus in some children with gelastic epilepsy. The MRI scan is more powerful than the computed tomography (CT) brain scan and therefore more likely to show very small tumours.

Treatment

The anti-epileptic drugs (AEDs) used to treat partial (focal) seizures may also be effective in treating gelastic epilepsy. These include carbamazepine (Tegretol), clobazam (Frisium), lamotrigine (Lamictal), levetiracetam (Keppra), oxcarbazepine (Trileptal) and topiramate (Topamax).

Unfortunately none of these medications or any other AEDs are likely to stop all seizures from happening.

A surgical treatment or 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 causing the gelastic epilepsy. These treatments are only available in very few specialist centres in the UK.

If the 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, but may improve after a surgical or radiotherapy treatment if the cause is due to a hamartoma.

Prognosis (outlook)

The gelastic and other types of seizures are often very difficult to control. It is rare for anyone to have their seizures controlled for more than a few weeks or months at a time.

The best outcome is probably seen in those children (and adults) who have a benign tumour in the hypothalamus (the hamartoma or astrocytoma) 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.

Hamartoma is a benign (noncancerous) growth made up of an abnormal mixture of cells and tissues normally found in the area of the body where the growth occurs.

Astrocytoma is a nervous system tumor that grows from astrocytes (astrocytomas are a type of glial cell. Glial cells are the supporting cells of the nervous system).

Support Organisation(s)

HHUGSUK (Hypothalamic Hamartoma Uncontrolled Gelastic Seizures)
ABS House
35 Chiltern Avenue
Amersham, Bucks
HP6 5AE
England

email: hhugsuk@hotmail.com
telephone: (UK) 00441494 728564
fax: (UK) 0044 1494 726042

Contact a Family,
209-211 City Road,
London,
EC1V 1JN

telephone 0808 808 3555
http://www.cafamily.org.uk/

11 July 2007

If you would like any more information about epilepsy, then please contact Epilepsy Action via the Email Helpline or, if you live in the UK, by phoning the Freephone Helpline on 0808 800 5050. More information about Landau Kleffner syndrome is available from FOLKS (Friends Of Landau Kleffner).