Hypothalamic hamartomas

Hypothalamic hamartomas are rare malformations of fetal brain development, affecting development of them hypothalamus, and are placed within the spectrum of grey matter heterotopia. Pathologically, lesions show mature neuronal and glial cells and some myelinated fibers. Hypothalamic hamartomas are associated with different clinical presentations, depending upon the site of attachment of the hamartoma. Hamartomas that are attached posteriorly in the region of the mammillary bodies cause seizures. Hamartomas attached anteriorly in the region of the tuber cinereum cause central precocious puberty. Larger lesions with anterior and posterior attachment cause both seizures and central precocious puberty.

Hypothalamic hamartoma occurs in both sexes, with a male predominance. Seizure onset is typically under the age of 1 year, typically present from birth, but often recognized in retrospect after emergence of other seizure types.

Developmental and learning impairments (of variable severity and worse with uncontrolled seizures early on) and psychiatric disorders are seen in 80%.

Proactive seizure control is important, this may include epilepsy surgery, if seizures are not controlled with medication. The cause may be sporadic (95%) or Pallister-Hall syndrome (5%). This syndrome includes polydactyly, a bifid epiglottis, dysplastic nails, imperforate anus, kidney abnormalities and hypothalamic hamartoma.

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