OP58 – 2844: Characterization of abnormal laughter in children and young people with epilepsy: A video EEG study

Abstract

Objective Gelastic seizures, characterized by epileptic laughter, are rare and the majority are usually associated with hypothalamic hamartomas and sometimes focal epilepsies with temporal, frontal lobe or insular foci. However abnormal laughing attacks in children and young people with epilepsy can be associated with other seizure types or may also be non-epileptic in nature. This study was undertaken to identify the aetiology of abnormal laughter in children and adolescents with epilepsy undergoing video EEG monitoring. Methods We carried out a retrospective review of all EEG studies performed in children and young people with epilepsy for episodes of paroxysmal abnormal laughter at a specialist residential epilepsy centre in UK. Data was analyzed to identify the cases of epileptic seizures characterized by ictal laughter and estimate the occurrence of non-epileptic events presenting as abnormal laughter. Results 36 children and young people (M:F 26:10), mean age 12.7 yrs (age range 4–19 yrs) underwent video-EEG monitoring between April 2000 and January 2015 to investigate episodes of paroxysmal laughter. Attacks of episodic laughter were captured in 28 patients. Of these, two patients (7%) had gelastic seizures as the only seizure type, 9/28 (32%) had ictal laughter as part of their other habitual seizures (epileptic spasms in 4/9 cases). 17/28 (61%) patients had episodes that were solely non-epileptic in nature. One boy with gelastic seizures had a hypothalamic hamartoma and 6 children with ictal laughter had symptomatic focal epilepsy. All patients with non-epileptic events had associated learning and behavioral difficulties. Conclusion In this population, the majority of episodic abnormal laughter in children and young people with epilepsy is not ictal in nature, but due to their associated comorbidities. True gelastic seizures are very rare; however there is also a significant occurrence of epileptic laughter as part of other seizure types, especially in symptomatic focal epilepsies.