A gelastic seizure, also known as "gelastic epilepsy", is a rare type of seizure that involves a sudden burst of energy, usually in the form of laughing. This syndrome usually occurs for no obvious reason and is uncontrollable. It is slightly more common in males than females. This syndrome can go for very long periods of time without a diagnosis, as it may resemble normal laughing or crying if it occurs infrequently. It has been associated with several conditions, such as temporal and

frontal lobe The frontal lobe is the largest of the four major lobes of the brain in mammals, and is located at the front of each cerebral hemisphere (in front of the parietal lobe and the temporal lobe). It is parted from the parietal lobe by a Sulcus (neur ...

lesion A lesion is any damage or abnormal change in the tissue of an organism, usually caused by injury or diseases. The term ''Lesion'' is derived from the Latin meaning "injury". Lesions may occur in both plants and animals. Types There is no de ...

tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

atrophy Atrophy is the partial or complete wasting away of a part of the body. Causes of atrophy include mutations (which can destroy the gene to build up the organ), malnutrition, poor nourishment, poor circulatory system, circulation, loss of hormone, ...

tuberous sclerosis Tuberous sclerosis complex (TSC) is a rare multisystem autosomal dominant genetic disease that causes non-cancerous tumours to grow in the brain and on other vital organs such as the kidneys, heart, liver, eyes, lungs and skin. A combinatio ...

hemangioma A hemangioma or haemangioma is a usually benign vascular tumor derived from blood vessel cell types. The most common form, seen in infants, is an infantile hemangioma, known colloquially as a "strawberry mark", most commonly presenting on the sk ...

s, and post-infectious foci, but mainly hypothalamic hamartomas. The term "gelastic" originates from the Greek word , which means laughter.

Signs and symptoms

The main sign of a gelastic seizure is a sudden outburst of laughter with no apparent cause. The laughter may sound unpleasant and sardonic rather than joyful. The outburst usually lasts for less than a minute. During or shortly after a seizure, an individual might display some twitching, strange eye movements, lip smacking, fidgeting or mumbling. If a person who has the seizures is hooked up to an

electroencephalogram Electroencephalography (EEG) is a method to record an electrogram of the spontaneous electrical activity of the brain. The bio signals detected by EEG have been shown to represent the postsynaptic potentials of pyramidal neurons in the neoc ...

, it will reveal interictal

epileptic Epilepsy is a group of non-communicable neurological disorders characterized by a tendency for recurrent, unprovoked seizures. A seizure is a sudden burst of abnormal electrical activity in the brain that can cause a variety of symptoms, rang ...

discharges. This syndrome usually manifests itself before the individual reaches the age of three or four. The temporal lobes, and the

hypothalamus The hypothalamus (: hypothalami; ) is a small part of the vertebrate brain that contains a number of nucleus (neuroanatomy), nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrin ...

are the areas of the brain with the most involvement with these seizures. This may cause

learning disabilities Learning disability, learning disorder, or learning difficulty (British English) is a condition in the brain that causes difficulties comprehending or processing information and can be caused by several different factors. Given the "difficulty ...

, and faulted

cognitive function Cognitive skills are skills of the mind, as opposed to other types of skills such as motor skills, social skills or life skills. Some examples of cognitive skills are literacy, self-reflection, logical reasoning, abstract thinking, critical th ...

as well. It is not uncommon for children to have tonic–clonic seizures, and atonic seizures directly following the seizure. Those that are associated with hypothalamic hamartomas may occur as often as several times hourly and typically begin during infancy. Seizures that occur in infancy may include bursts of cooing, respirations, giggling, and smiling. Due to early

hypothalamic–pituitary–gonadal axis The hypothalamic–pituitary–gonadal axis (HPG axis, also known as the hypothalamic–pituitary–ovarian/testicular axis) refers to the hypothalamus, pituitary gland, and gonadal glands as if these individual endocrine glands were a single en ...

activation in girls who have the seizures, it is not uncommon for them to display

secondary sex characteristics A secondary sex characteristic is a physical characteristic of an organism that is related to or derived from its sex, but not directly part of its reproductive system. In humans, these characteristics typically start to appear during puberty ...

before the age of eight.

Causes

A gelastic seizure is classically associated with a hypothalamic hamartoma (a type of

brain tumor A brain tumor (sometimes referred to as brain cancer) occurs when a group of cells within the Human brain, brain turn cancerous and grow out of control, creating a mass. There are two main types of tumors: malignant (cancerous) tumors and benign ...

). A hypothalamic hamartoma is defined as a

benign Malignancy () is the tendency of a medical condition to become progressively worse; the term is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous benign tumor, ''benign'' tumor in that a malig ...

mass of

glial Glia, also called glial cells (gliocytes) or neuroglia, are non-neuronal cell (biology), cells in the central nervous system (the brain and the spinal cord) and in the peripheral nervous system that do not produce Action potential, electrical ...

tissue on or near the

. The size of the hamartoma can vary from one centimeter to larger than three centimeters. They can cause several different types of seizures including a Gelastic Seizure. These structures can be detected with different imaging modalities such as

computed tomography A computed tomography scan (CT scan), formerly called computed axial tomography scan (CAT scan), is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or ...

, magnetic resonance imaging,

single-photon emission computed tomography Single-photon emission computed tomography (SPECT, or less commonly, SPET) is a nuclear medicine tomography, tomographic imaging technique using gamma rays. It is very similar to conventional nuclear medicine planar imaging using a gamma camera ...

(SPECT) and

positron emission tomography Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, r ...

(PET-CT). A computed tomography scan of an individual with a hypothalamic hamartoma would reveal a

suprasellar The sella turcica (Latin for 'Turkish saddle') is a saddle-shaped depression in the body of the sphenoid bone of the human skull and of the skulls of other hominids including chimpanzees, gorillas and orangutans. It serves as a cephalometric la ...

mass with the same density as brain tissue. Images of these masses are not enhanced with the use of contrast. However, although a computed tomography scan may be useful in diagnosing the cause of a seizure, in the case of a hypothalamic hamartoma, magnetic resonance imaging is the tool of choice due to the

cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless Extracellular fluid#Transcellular fluid, transcellular body fluid found within the meninges, meningeal tissue that surrounds the vertebrate brain and spinal cord, and in the ventricular system, ven ...

which defines these masses. SPECT may also be used which involves the use of a radiotracer that is taken up by the

ictal The postictal state is the altered state of consciousness after an epileptic seizure. It usually lasts between 5 and 30 minutes, but sometimes longer in the case of larger or more severe seizures, and is characterized by drowsiness, confusion, nau ...

region of the brain where, typically the tumor lies. PET-CT using F-18 fluorodeoxyglucose (FDG) show reduced metabolism at the site of seizure onset. Gelastic seizures have been observed after taking a birth control pill (Maxim (R)). Optic nerve hypoplasia is the only reported condition with gelastic seizures without hypothalamic hamartomas, suggesting that hypothalamic disorganization alone can cause gelastic seizures.

History

Very likely gelastic seizures were already recognized at the time of

Babylonian medicine Babylonia (; , ) was an Ancient history, ancient Akkadian language, Akkadian-speaking state and cultural area based in the city of Babylon in central-southern Mesopotamia (present-day Iraq and parts of Kuwait, Syria and Iran). It emerged as a ...

. A detailed description was given by the Scottish physician

Robert Whytt Robert Whytt (1714–1766) was a Scottish physician. His work, on unconscious reflexes, tubercular meningitis, urinary bladder stones, and hysteria, is remembered now most for his book on diseases of the nervous system. He served as President of ...

in 1765, and the term "gelastic seizure" was coined in 1898 by the French neurologist, neuropathologist and epileptologist Charles Féré.

Notable cases

* George William Helon (Australian author and businessman) is a gelastic seizure patient, mentor, counsellor and advocate.

Media references

Gelastic syncope was also referred to in one paper also as "Seinfeld syncope" after an incident in which a patient repeatedly fainted while watching an episode of ''

Seinfeld ''Seinfeld'' ( ) is an American television sitcom created by Larry David and Jerry Seinfeld that originally aired on NBC from July 5, 1989, to May 14, 1998, with a total of nine seasons consisting of List of Seinfeld episodes, 180 episodes. It ...

''.

References

{{Reflist

External links

MR imaging of hypothalamic hamartoma
Seizure types Laughter