Positron emission tomography with glucose hypermetabolism of a hypothalamic hamartoma in infantile spasms associated with Pallister-Hall syndrome.

Although hypothalamic hamartomas (HHs) have been shown to be intrinsically epileptogenic and to participate in the generation of gelastic seizures, no evidence has been reported regarding its contribution to the pathogenesis of infantile spasms. We describe a male infant with Pallister-Hall syndrome who had a large HH presenting with infantile spasms without hypsarrhythmia. [(18)F]fluoro-deoxyglucose positron emission tomography scan performed during the period of epileptic spasms demonstrated glucose hypermetabolism of the HH, which resolved after cessation of the spasms with adrenocorticotropin hormone treatment. No concurrent increased metabolic activity in the lenticular nuclei or brainstem was observed in the ictal or interictal states. The present case suggests that HHs may be involved in the pathogenesis of infantile spasms, possibly with propagation of epileptic discharges from the hamartoma to the descending spinal pathway.