sir/madam my granddaughter name dolly she is 5.1 years old past 15 days she laughing uncontrollably many times a day what is the reason is it normal? biting things or clothes frequently ..

A. I feel it is gelastic seizures, and appear as spontaneous, uncontrollable and often maniacal giggles or laughter. They are short and unpredictable. The cause: a rare form of epilepsy called Hypothalamic Hamartoma (HH) in which a non-cancerous lesion wreaks havoc in a highly sensitive area near the brain's stem.