[Hypothalamic hamartoma: clinical characteristics. Electroencephalogram and brain magnetic resonance imaging in 10 patients].

INTRODUCTION: We describe clinical findings and electroencephalogram (EEG) in patients with hypothalamic hamartoma and epilepsy. METHODS: Our group includes 10 patients (eight males) with mean age of 17.8 years (range: 7-39) and hypothalamic hamartoma in the brain magnetic resonance imaging (MRI). We analyzed clinical data, seizure semiology, MRI and EEG findings of the neuropsychological study. RESULTS: Nine patients had gelastic seizures, that initiated at a mean age of 17.1 months (2 days-5 years). Other types of seizure were observed in seven and five had behavior disorders. Intelligence quotient (IQ) was below the mean range in three. Three children had precocious puberty and thyroid dysfunction. One patient did not have epilepsy. MRI showed a hypothalamic lesion suggesting hamartoma associated to a dysplastic lesion in one case. The interictal EEG was normal in 2 cases and revealed epileptiform abnormalities, consisting of spikes or sharp waves, in temporal regions, frontal, fronto-temporal regions and central-parietal in 8. Three patients had paroxysmal discharges of generalized fast activity (> 10 Hz) during non-REM sleep. Forty seizures were recorded, 31 had an ictal EEG pattern while the EEG was normal in 9. CONCLUSIONS: In our group gelastic seizures were an early and constant finding except in one patient. Partial complex seizures, behavior alteration and cognitive decline were frequent. Video-EEG monitoring allows us to identify interictal and ictal patterns that have been described in hypothalamic hamartomas.