Association of morphological characteristics with precocious puberty and/or gelastic seizures in hypothalamic hamartoma

The pathogenesis of central precocious puberty (PP) and/or gelastic seizures due to a hypothalamic hamartoma (HH) is still under debate. We evaluated the association of clinical symptoms with morphology and localization of the HH in 34 patients. The majority (86.4%) of HHs in patients with isolated PP (n = 22; 68.2% females) revealed a parahypothalamic position without affecting the third ventricle (91%). Half of them were pedunculated, and 40.9% showed a diameter less than 10 mm. In contrast, 11 of 12 patients with seizures, eight of whom were male, presented with a sessile intrahypothalamic hamartoma, 10 of which distorted the third ventricle. Logistic regression analysis revealed an increased relative risk (RR) for epilepsy in males (RR, 4.3; 95% confidence interval, 0.96-19). However, combination of the risk factor gender with intrahypothalamic position (RR, 19; 1.3-285) and distortion of the third ventricle (RR, 10; 0.6-164) reduced the risk associated with male gender to 1.1. The position of a HH and involvement of the third ventricle are likely to be more predictive for clinical characteristics than size and shape. Male gender was associated with an intrahypothalamic HH and epilepsy, suggesting a sexually dimorphic developmental pattern of this heterotopic mass.