Diagnostic dilemma: Brain lesion causes woman to experience lifelong bouts of unpleasant laughter

Patient: 31 year old female

Symptoms: This woman came to the clinic because she had been experiencing uncontrollable laughter for years, which doctors described as “creepy laughter” in her case report. According to the patient, she had had intermittent episodes of involuntary laughter like this since childhood, but her condition was never formally investigated or diagnosed.

She said she feels a “feeling of fear” in her neck and chest before each episode begins. While she burst into laughter, she was unable to speak or swallow and had trouble breathing. Each outburst lasted a few seconds and usually occurred about once a day, usually right after the woman woke up in the morning.

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The woman said that as a child, each episode lasted several minutes and occurred more frequently, about six or seven times a day, sometimes while she was sleeping. Her parents did not realize that the laughter was beyond her control. Rather, the patient reported that they would think her laughter was intentional and ask her to stop. As she grew older, her bouts of laughter became shorter and less frequent.

What happened next: Before the patient came to the clinic, an MRI and electroencephalogram (EEG) of her brain showed no abnormalities. However, when clinicians examined videos of her laughing episodes, they noticed that they were very similar to gelastic seizures. This type of seizure commonly causes uncontrollable laughter, giggling, or grinning, but can also cause groaning, mumbling, or lip-smacking symptoms. It is named after the Greek word “gelastikos” meaning laughter.

Collagen seizures are usually localized and caused by abnormal electrical activity in specific parts of the brain. During a second MRI, doctors discovered an area of ​​abnormality in the hypothalamus, an important structure for maintaining homeostasis. The width of the anomaly was approximately 5 mm.

Diagnosis: They identified the lesion as a hypothalamic hamartoma, a non-cancerous lesion that develops during fetal development. Involuntary laughter attacks, in which the person is aware of their actions but are unable to control them, are characteristic of this seizure. The exact reason why these lesions cause laughter attacks is not fully understood.

Treatment: The patient had previously tried levetiracetam and lamotrigine, anti-seizure drugs used to treat epilepsy, but they had no effect. Since her symptoms were not serious, the woman decided that she did not want drugs.

Because she had no other behavioral or cognitive problems and the severity and frequency of her seizures decreased over time, doctors at the clinic determined that no additional treatment was necessary.

Characteristics of this case: Hypothalamic hamartomas are rare, but when they occur, they are usually associated with cognitive and behavioral deficits. In children, the hypothalamus helps regulate hormones, so growth can cause developmental delays or the early onset of puberty. Patients who have gelatinous seizures caused by these lesions often develop more severe epilepsy and experience other types of seizures in the future.

This woman’s case is extremely rare because her symptoms naturally reduced to a manageable level. This benign outcome of epilepsy associated with hypothalamic hamartomas “has, to our knowledge, not been previously reported,” the doctors wrote.

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