Inappropriate Laughter and Behaviours: How, What, and Why? Case of an Adult with Undiagnosed Gelastic Seizure with Hypothalamic Hamartoma.

Gelastic seizures (GS) are a rare form of epilepsy characterized by inappropriate, uncontrolled laughter. They are highly associated with abnormal cognitive development and behavioral problems in patients. Research has shown that GS can originate from hypothalamic hamartomas (HH), non- neoplastic masses consisting of gray matter with large and small neurons interspersed with glial nuclei. GS have also been observed in patients with frontal and temporal lobe lesions. The patient in this case report is a 40-year-old man with a past medical history significant for brain tumor, diabetes mellitus, and schizophrenia who presented with a long standing history of sudden, involuntary laughter occurring 2-3 times a week since 8 years old. Since the onset of these laughing spells the patient has displayed gradual cognitive impairment and increasing behavioral problems. Subsequent EEG (21-channel electroencephalogram) showed focal epileptiform activity in the right frontotemporal region and MRI studies revealed a mass arising from the hypothalamus suggestive of a HH. Other conditions should be considered in the differential diagnosis for laughing spells and distinguishing different causes can be challenging. As demonstrated by this case report, in patients with behavioral issues, especially those with inappropriate uncontrolled laughter, gelastic seizures need to be included in the differential diagnosis. Thus, a thorough workup should include neuroimaging with attention to the suprasellar region and EEG. Accurate, early diagnosis and patient education are critical in avoiding excessive and unnecessary treatments. This condition may be pharmacoresistant and is often associated with progressive cognitive and behavioral issues. Studies have shown a surgical treatment approach may be effective.