Dental Hardware Complicating Diagnosis in Refractory Gelastic Epilepsy Secondary to Hypothalamic Hamartoma

Hypothalamic hamartomas (HH) are developmental malformations of the hypothalamus associated with a potentially treatable epileptic encephalopathy, characterized by early onset gelastic seizures, the later development of multiple seizure types and progressive cognitive and behavioral decline. Surgical treatment of HH can lead to seizure control and improvement in the cognitive-behavioral syndrome. Video-EEG telemetry (VET) is often necessary to characterize the semiology of the seizures, but there are no specific interictal or ictal EEG patterns that will confirm the diagnosis. Magnetic resonance imaging (MRI) can identify HH and define their anatomy, but the imaging findings may be subtle and susceptible to artifactual contamination. We present a patient with intractable gelastic epilepsy in whom the diagnosis of HH was initially missed due to failure to recognize the clinical syndrome and contamination of the MRI images with dental hardware artifact. VET confirmed the clinical diagnosis and the HH was identified on MRI after the dental hardware was removed. VET should be performed to confirm seizure semiology in patients with suspected gelastic epilepsy. Establishing this diagnosis can subsequently direct the appropriate neuroradiological evaluation for HH and surgical treatment of these lesions.