Temporal Lobe Hypometabolism Ipsilateral to a Hypothalamic Mass. Relationship to Gelastic Seizures

The purpose of this study was to investigate metabolic changes associated with a right hypothalamic mass in a 26-year-old gelastic seizure patient. Positron emission tomography (PET) imaging of the brain was performed in the interictal state using 18F-fluorodeoxyglucose (18F-FDG) in this patient. Temporal lobe hypometabolism was noted ipsilateral to the hypothalamic lesion. The mass itself had little to no uptake of 18F-FDG. This is the first known PET imaging report of temporal lobe hypometabolism ipsilateral to a presumed hypothalamic hamartoma causing gelastic seizures. Further studies are needed in other patients to test whether interictal PET imaging may help plan the removal of epileptogenic hypothalamic lesions.