Loss of consciousness can follow laughter in Angelman patients
Gelastic syncope, as condition is known, in need of further study
Some people with Angelman syndrome may experience a phenomenon known as gelastic syncope, where laughter leads to a loss of consciousness, a report involving a teenager and two adults highlights.
“The goal of this article is to bring specific awareness of gelastic syncope to clinicians and caregivers and to help form a framework for guiding diagnosis, data collection, and treatment,” the researchers wrote.
The article, “Gelastic spells in Angelman Syndrome, when laughter isn’t funny,” was published in Epilepsy & Behavior Reports.
‘Contagious laughter’ of Angelman patients among syndrome’s joys
Angelman syndrome is a genetic disorder characterized by abnormalities in development and behavior. Among its hallmark features is that people with the condition tend to be very happy and prone to laughter. While this can be delightful, it also can be worrisome.
“One of the joys of working with this patient population is the abundance of happiness and the ever-present and contagious laughter of our children and adults with AS [Angelman syndrome]. Unfortunately, laughter may pose additional challenges leading to loss of tone, syncope [loss of consciousness], and falls,” the researchers wrote.
Scientists described the experiences of three Angelman patients — a 25-year-old woman, a 32-year-old man, and a 14-year-old boy — who had repeated episodes where they would laugh, then seem to go blank or lose consciousness, sometimes to the point of collapsing.
“He continued to laugh until he seemed to blank out, then his eyes rolled back, and he collapsed,” they wrote of an episode involving the man. “The entire event was only a few seconds long.”
They outlined three potential explanations for these spells. One is seizures triggered by the laughter, called gelastic seizures, possibly secondary to hyperventilation, a state of rapid or deep breathing that results in an excessive elimination of carbon dioxide from the body.
Another potential reason for these spells is cataplexy, a phenomenon similar to narcolepsy, where intense emotions trigger a sudden loss of muscle tone. Â But cataplexy usually is not associated with loss of consciousness.
The third potential explanation is gelastic syncope. In this phenomenon, intense laughter causes abnormalities in the nerve signals that control heart rate and blood pressure; as a result, blood pressure drops and heart rate slows, so the brain isn’t getting enough blood, which can result in a loss of consciousness.
Distinguishing between seizures and syncope crucial in guiding treatment
Researchers then outlined how to differentiate between these different phenomena. The first step, they stressed, is to perform detailed clinical histories and extensive talks with the patient’s caregivers to understand exactly what is happening. Home video recordings can be invaluable for these discussions, the scientists said.
Ideally, it may be possible to distinguish seizures and syncope by measuring the brain’s electrical activity during an episode, but this often isn’t practical. An alternative might be to use EKGs, which measure the heart’s electrical activity and can be done at home with worn devices, detecting changes in heart rate that confirm or rule out gelastic syncope.
Distinguishing between seizures, cataplexy, and syncope is crucial to guiding treatment, the researchers noted. For patients with seizures, anti-seizure medicines are recommended, whereas antidepressants are often effective for controlling cataplexy.
In cases of gelastic syncope, first-line management involves limiting time spent standing up and making sure the patient drinks lots of fluid and consumes more salt, which can help keep blood pressure up. If this doesn’t work, medications such as antidepressants may be tried. However, the researchers noted that data are limited on whether particular medications are effective in Angelman patients experiencing gelastic syncope.
The scientists called for further studies to explore laughter-related episodes in Angelman patients and to test treatment options.
“A better understanding of the frequency of such events, specific triggers, and the specific clinical manifestations will help improve our understanding of the spells and may help guide treatment of them, if and when indicated,” they wrote.
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