Abstracts

Rationale: Hypothalamic hamartoma (HH) is a rare disease associated with gelastic and dacrystic seizures and at times secondary focal and generalized seizures in untreated patients. The clinical severity varies from only gelastic seizures with otherwise normal development to focal drug-resistant epilepsy or generalized encephalopathy with severe cognitive and behavioral impairments. Although a rare diagnosis itself, HH has been associated with epileptic spasms (ES) in a small percentage. Methods: This is a retrospective, comprehensive, observational review of 103 patients with HH and epilepsy referred to Texas Children’s Hospital (TCH), Houston, Texas between March 2011 and August 2019 to identify those patients with HH and a history of ES. Results: A total of 103 patients were identified with HH. Only three patients (2.9%) with HH had ES while the rest had gelastic only or gelastic and other seizure types. All patients with ES were male patients. At the time of presentation to TCH, the mean patient age was 35 months (14-63 months range). Gelastic seizure started between 1st week to 2 months of life and mean age of onset for ES was 10 months (6-18 months range). Two patients had documented hypsarrythmia on EEG. Two had developmental regression with onset of ES in addition to global developmental delays. ES resolved with oral prednisolone as first line treatment in one and vigabatrin alone was sufficient in another patient. The third patient was never treated with steroids or vigabatrin and continued to have spasms, despite multiple antiepileptic medications and partial resection of HH at outside hospital. Two developed precocious puberty. HH was the only anatomic abnormality seen on brain MRI, interestingly only obtained in all patients after the onset of ES. PET (positron emission tomography) scan revealed different findings for these patients including hypo metabolism within HH only, heterogeneous hypo metabolism within HH with bilateral frontal-temporal hypo metabolism, or hypo metabolism temporal and left occipital lobe. The latter two had MEG scan that showed spikes over broad left temporal-parietal more than right temporal regions and spikes in bilateral temporal, parietal and occipital region representing a more generalized process respectively. All three patients underwent MRI-guided laser ablation of HH at age of 14, 29 and 63 months. The oldest patient had a previous partial HH resection with frontozygomatic approach 2 years prior to ablation at another institution. At time of laser ablation, they had only gelastic seizures, gelastic and focal tonic or gelastic, dacrystic, focal seizures with altered awareness and IS. Two became seizure free after the laser ablation and one continued to have focal tonic with gelastic features; however, seizure burden was decreased by 93% at almost 4 years post surgery with complete resolution of ES. The follow up ranges from 2 weeks to 47 months after the surgery. The brief follow up data is due to patient undergoing surgery recently. Conclusions: All patients presenting with ES with or without gelastic seizures should be evaluated for HH. Although ES in HH may be successfully treated with steroids and/or vigabatrin, considering early laser ablation could potentially treat epileptic spasms along with all other seizure types associated with HH. Funding: No funding