A type of seizure characterized by sudden, uncontrollable laughter or smiling, often without an emotional provocation. These seizures originate from the hypothalamus or other areas of the brain responsible for regulating emotions and behavior. The laughter that accompanies gelastic seizures is often inappropriate, occurs for no apparent reason, and may be accompanied by other signs such as facial twitching, automatisms, or a brief loss of consciousness. Most often, such seizures are observed in hypothalamic hamartomas, but can also occur in epileptic syndromes or brain tumors. Treatment often includes antiepileptic medications, and in some cases, surgery is considered if the seizures do not respond to drug therapy.