What is Gelastic Epilepsy?
Gelastic epilepsy refers to a type of epilepsy in which the seizures are 'gelastic', gelastikos being the Greek word for laughter. A gelastic seizure is defined as sudden occurrence of emotions in the form of a laugh or a cry. Usually the seizure lasts around 5 to 60 seconds. In most cases gelastic seizures are associated with other seizure types.
There are a wide range of causes for gelastic seizures, and neuroimaging investigations (MRI) are often required to delineate the cause. A very 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). If the child also has precocious puberty, then this can be treated with hormones or hormone-like medicines.
The anti-epileptic drugs (AEDs) used to treat 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), amongst others.
Unfortunately none of these medications or any other AEDs are likely to stop all seizures from happening when associated with hypothalamic hamartoma, and it is rare for anyone to have their seizures controlled for more than a few weeks or months at a time.
Epilepsy and Gelastic Epilepsy
Seizures may begin at any age but in the setting of hypothalamic Hamartoma 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.
The laughter usually lasts less than one minute and is then followed by signs that are more usually recognised with focal dyscognitive 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.
People with Gelastic Epilepsy 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 known as drop seizures).
Surgery of hypothalamic hamartoma may improve not just the patient’s seizure control but also improve behavioural and learning problems.
Educational Implications for Children
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. Unfortunately, the learning and behavioural problems rarely respond to medical treatment, but may improve after surgical treatment if the cause is due to a hamartoma.
Dr Richard Appleton, a Consultant Paediatric Neurologist. Dr Rachel Kneen, Consultant Paediatric Neurologist.
Dr Stewart Macleod, Specialist Registrar in paediatric neurology. Alder Hey at Alder Hey Children’s Hospital, Liverpool.
Updated August 2013. To be reviewed August 2015.
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