Gelastic seizures
Incidence
Gelastic seizures are very rare affecting 1 in every 1000 people with epilepsy. Gelastic seizures (GS) affect boys slightly more than girls.
Clinical Characteristics
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. Seizures may begin at any age but usually before three or four years of age. It is considered an epileptic syndrome. Age of onset of gelastic seizures can begin in neonates to 5 years of age if the seizures are secondary to a hypothalamic hamartoma. However, if the seizures are secondary to another epileptic focus such as frontal or temporal lobe epilepsy, they may not be manifested until over the age of 5 years. 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 recognized 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 seizure may occur several times per day or every hour. During school-age years, the seizures usually become more complicated, other seizure types develop, and cognitive deterioration occurs. Severe behavior problems are common, and the seizures are usually intractable. Gelastic seizures can occur in patients with epileptic encephalopathy, precocious puberty and autistic spectrum disorders. The electroencephalogram (EEG) can show focal and generalized sharp waves, spikes or spike and slow waves. An MRI should be performed to search for a hypothalamic hamartoma. The prognosis of gelastic seizures depends on the underlying pathology. The seizures originating from frontal lobes, temporal lobes, or other regions of the brain usually have a better outcome than those associated with hypothalamic origin. If a hypothalamic hamartoma is diagnosed, surgery is an option. Secondary seizure manifestations may improve with medications including carbamazepine, clobazam, lamotrigine, levetiracetam, oxcarbazepine and topiramate.
Precipitants
Seizures may be triggered by sleep deprivation, infections, fever, vomiting, or diarrhea.
Provocation Tests
There are no specific provocation tests to confirm the diagnosis but EEG, MRI and the history are necessary to make the diagnosis.
Diagnostic Procedures
It is a clinical-EEG 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 behavioral 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. EEG, MRI and the history are necessary to make the diagnosis.