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  • Updated 10.20.2025
  • Released 05.07.2001
  • Expires For CME 10.20.2028

Focal seizures with laughing

Authors
Kate Riney MB BCh BAO PhD, Ellen West DCH MBBS FRACP
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Editor
Solomon L Moshé MD
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Cite this article

Introduction

Overview

Laughter is a behavior that occurs in both emotional and nonemotional contexts. Emotional laughter occurs in the context of mirth (amusement), whereas nonemotional laughter is a voluntary complex motor phenomenon and is used for social communication, usually in conversation. These two types of laughter are produced by two distinct brain networks.

International classifications of epilepsy, seizures, and epilepsy syndromes have been updated in recent years. The 2017 classification of seizures emphasized that when laughter was the first feature in a focal seizure, the seizure was a “focal emotional seizure with laughing.” A more recent classification of seizures in 2025 allows that a focal seizure with laughing might occur as a motor or emotional (“affective”) phenomenon and, thus, might be a focal seizure with gelastic “mimic automatism” or might be a focal seizure with emotional phenomena (specifically mirth). This focal seizure provides a unique insight into the neurobiology of laughter.

In this article, the authors review the updated classification of this seizure type, associated etiologies (particularly hypothalamic hamartoma), clinical presentations, differential diagnoses, and current treatments. Newer, noninvasive surgical treatments for seizures due to hypothalamic hamartomas are also reviewed.

Key points

• Focal seizures with laughing are characterized by unprovoked and stereotyped laughing or giggling, with or without the accompanying emotion of mirth.

• The differential diagnosis for focal seizures with laughing includes focal motor seizures causing facial expression change or asymmetry (movements distinct from the sequence seen in laughter), pseudobulbar affect laughter, gelastic cataplexy, gelastic syncope, and functional neurologic symptom disorder.

• Focal seizures with laughing, particularly focal seizures with gelastic mimic automatisms, are classically associated with hypothalamic hamartomas but may also be seen in structural pathologies in the temporal or frontal lobes.

• When associated with hypothalamic hamartomas, focal seizures with laughing are typically intractable to medical therapy and may be one of the early symptoms of the condition.

• The most effective treatment for focal seizures with laughing associated with a hypothalamic hamartoma involves surgery to the hamartoma.

Historical note and terminology

The possibility of sudden emotion as a manifestation of an epileptic seizure has been recognized since the end of the 19th century (71). These emotions were usually negative, and the emotion of fear was most often described. Seizures with laughing were first described by Trousseau (78). Gowers observed emotions "with a cheerful character" as part of a seizure (28). Daly and Mulder coined the term “gelastic epilepsy” from the Greek word gelos, meaning “laughter,” to emphasize the main feature of these seizures (15). Gascon and Lombroso subsequently suggested the following criteria for the diagnosis of "gelastic epilepsy": stereotyped recurrence; absence of external precipitants; concomitance of other manifestations generally accepted as epileptic; presence of interictal or ictal epileptiform discharges on EEG; and absence of conditions in which pathologic laughter might occur (25).

In the updated classification of the epilepsies in 2017 (65), the International League Against Epilepsy (ILAE) limited epilepsy types to four: focal, generalized, combined generalized, and focal and unknown. This rendered the term “gelastic epilepsy” obsolete. In a subsequent operational definition of seizure types in 2017, the ILAE subsequently classified seizures with laughing as the first seizure feature as a type of focal nonmotor seizure, a focal emotional seizure--specifically a “focal emotional seizure with laughing” (allowing the synonym of “focal emotional gelastic seizure”) (19; 20). Depending on whether awareness was preserved, the seizure was classified as a focal aware emotional seizure with laughing or a focal impaired awareness emotional seizure with laughing. The application of the term “emotional” only required the appearance of having an emotion (“affective manifestation”), not that the subjective emotion is present. Thus, the classification of a focal emotional seizure with laughing did not distinguish whether the laughter was a motor phenomenon or due to the emotion of mirth.

In the 2017 seizure classification, laughing was only used to classify a seizure if it was the initial feature. When it appeared after another initial seizure feature, it was not used to define the seizure type but instead was a “descriptive” seizure term--a term applied to describe features seen in the seizure evolution. A patient with a seizure commencing with a fast heart rate, and laughing later, was considered to have a focal autonomic seizure (with laughter seen in the seizure evolution). In the 2025 ILAE classification of seizures (03), focal seizures were simplified to the three seizure types: focal preserved consciousness seizure, focal impaired consciousness seizure, and focal-to-bilateral tonic-clonic seizure. The classification of focal nonmotor seizures (including focal emotional seizures with laughing) that had been established in the 2017 classification was abandoned. The classification of a seizure based on the first feature of the seizure was also abandoned. Instead, emphasis was placed on the chronological sequence of phenomena in the seizure, and these were considered descriptors (basic or expanded). Under this classification, when laughing is seen in a focal seizure, a clinician could categorize this as either a complex motor phenomenon (a mimic automatism, specifically a gelastic mimic automatism) or as the expression of an emotional phenomenon (mirth) in the patient.

These two updates to the classifications of focal seizures with laughing in 2017 and 2025 reflect how different authors might have studied this entity over time and, thus, how published literature is interpreted. The distinction of whether a symptom or sign is the first feature of a seizure or a later feature may be important. The first feature can more precisely reflect the location of seizure onset, whereas later features can reflect seizure spread. Past literature on “gelastic seizures” or “gelastic epilepsy” did not make the distinction as to when in the seizure the laughing occurred, and these terms were previously used when laughing occurred at any time during the seizure. Thus, the described “gelastic seizures” or “gelastic epilepsy” could have various seizure onsets and etiologies, with different (or common) network propagation. Similarly, distinguishing whether laughter is a motor phenomenon or an emotional phenomenon has been challenging, especially in children. These two types of laughing reflect distinct brain networks, and both types of focal seizure with laughing likely reflect distinct seizure onsets and etiologies. In this article, the term “focal seizure with laughing” is used when referring to data from past literature on “gelastic seizures” prior to 2017, when the literature did not define whether laughing was present from seizure onset or at any time in the seizure evolution, or whether it was a motor or emotional phenomenon. In the future, literature may provide more precise information on the entities that result in laughing from clinical seizure onset or in laughing as a complex motor or as an emotional phenomenon. There has been debate as to whether entities with focal seizures with laughing compose an epilepsy syndrome. Arguments against this were raised because the syndrome would be largely defined based on a single seizure symptom (42). In 2022, the ILAE published a classification and definition of epilepsy syndromes, confirming that a syndrome requires a cluster of clinical and EEG features that are often supported by specific etiological findings (81). The etiology-specific epilepsy syndrome “gelastic seizures with hypothalamic hamartoma” was officially recognized (84).

The clinical entities associated with focal seizures with laughing have primarily been described in historical case series and case reports. These reports may be subject to ascertainment bias as they primarily arise from tertiary or epilepsy surgery centers. Data from the older studies can reflect limited detection of certain types of hypothalamic hamartomas or other structural brain abnormalities due to lower-resolution MRI in use at that time. Some studies can reflect findings from patients who developed a secondary epileptic encephalopathy and who have wider cortical and subcortical abnormalities and epilepsy comorbidities, rather than the primary epilepsy etiology. Older studies can reflect perspectives on the localization values of certain investigations or surgical techniques that have been superseded as imaging and surgical techniques have advanced. This article presents a review of the past literature, bearing in mind these limitations.

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