Gelastic seizure
Pronunciation: jeh-LAS-tik
A type of focal seizure characterized by inappropriate laughter or giggling, often associated with hypothalamic hamartomas.
Full Definition
Gelastic seizures are a distinctive type of focal seizure characterized by episodes of inappropriate, unmotivated laughter or giggling that occurs without associated mirth or emotional content. The term derives from the Greek word 'gelos' meaning laughter. These seizures are most commonly associated with hypothalamic hamartomas, benign developmental malformations near the third ventricle, though they can occasionally arise from other brain regions. Gelastic seizures often begin in infancy and may be followed by other seizure types. The laughter is typically described as hollow, emotionless, or mechanical, distinguishing it from normal laughter.
Usage
Usage note: From Greek 'gelos' (laughter); contrasts with 'dacrystic' (crying) seizures.
In Context
- "The infant's gelastic seizures prompted MRI imaging that revealed a hypothalamic hamartoma." — Pediatric neurology report
- "Video-EEG confirmed that the inappropriate laughter episodes were gelastic seizures rather than behavioral events." — Epilepsy monitoring unit report