Abstracts

A small number of patients with hypothalamic hamartoma (HH) present with infantile spasms (IS) as their initial seizure type. The relationship between HH and IS is unexplored. Study of the intersection of these two distinctive epilepsy syndromes may offer new insights into basic mechanisms of subcortical seizure activity. Our current case series of patients with HH and refractory epilepsy has been reviewed to identify those patients with HH and a history of IS. We have retrospectively reviewed the available medical records and radiological studies for the identified cases. A literature search, utilizing PubMed, was performed to identify prior studies reporting cases with HH and IS. We identifed 4 patients with HH and a history of IS in our current HH case series of patients reviewed for possible surgical treatment (N=122). Three of the 4 are male. Average age at time of evaluation was 11 years 10 months (range 16 months to 21 years). Average age at time of onset of IS was 8 months (range 6 months to 14 months). All 4 (100%) presented with IS as the initial seizure type. In retrospect, one patient had developed gelastic seizures at age 4 months, and IS at age 6 months. Results of initial EEG studies are available on two patients, and both showed hypsarrhythmia. All four patients were treated with ACTH, and all responded with resolution of epileptic spasms. However, other seizure types either continued, or evolved later, and all patients were ultimately refractory to medication management. All patients have undergone surgical resection of their HH (transventricular endoscopic approach in 2, orbitozygomatic approach in one, and transcallosal interforniceal approach in one). With brief follow-up, the two patients [lt]10 years of age at the time of surgery are seizure-free, and the two patients over 10 years of age at the time of surgery are [lt]50% improved. Review of the English-language literature reveals 6 other cases with HH and IS. Limited detail is provided. There are no reports specifically addressing the comorbidity of HH and IS. Based upon our series, and the available literature, IS occur in 2-4% of all HH patients. HH should be included in the differential diagnosis of infants presenting with IS. These patients may have hypsarrhythmia on initial EEG, and all patients in this series responded to ACTH with cessation of epileptic spasms. However, all eventually became refractory with seizure types more commonly seen in HH patients. Surgical resection of the HH can be effective for controlling seizures in this subgroup. It has been previously recognized that focal brain pathology may result in IS and generalized EEG abnormalities. The association of HH and IS demonstrates that such focal pathologies may be sub-cortical as well as cortical in location, and may provide new insights into IS pathogenesis. (Supported by Barrow Neurological Institute Foundation.)