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Hypothalamic Hamartoma

Abstract

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NORD is very grateful to John F. Kerrigan, M.D., Associate Professor of Clinical Pediatrics and Neurology, University of Arizona College of Medicine; Director, Hypothalamic Hamartoma Program, Barrow Neurological Institute at Phoenix Children's Hospital, for assistance in the preparation of this report.

Synonyms of Hypothalamic Hamartoma

  • HH (hypothalamic hamartoma)
  • hypothalamic hamartoblastoma

Disorder Subdivisions

  • central precocious puberty
  • epilepsy and related neurobehavioral symptoms

General Discussion

Hypothalamic hamartomas (HH) are rare, tumor-like malformations that occur during fetal development and are present at birth. They are non-progressive lesions and do not expand, spread or metastasize to other locations. They grow in proportion to normal brain growth, and consequently their relative size to the rest of the brain is the same for the lifetime of the patient when viewed with serial imaging. There is tremendous diversity in the type and severity of symptoms from patient to patient. However, symptoms are apparent during childhood in the overwhelming majority of patients. Although significant overlap exists, two clinical phenotypes of HH are recognized: Central precocious puberty and epilepsy and related neurobehavioral symptoms.

For those with central precocious puberty only, symptoms may occur as early as 2-3 years of age. These patients present with precocious (abnormally early) development of the physical changes associated with puberty. Neurological problems, such as epilepsy, are usually absent. Magnetic resonance (MR) imaging on patients with central precocious puberty typically shows attachment of the HH lesion in an anterior location in the hypothalamus, in the region of the tuber cinereum or pituitary stalk.

For those with epilepsy, gelastic (laughing) seizures, is the presenting symptom, often during infancy. Associated symptoms can include developmental delay, cognitive deterioration, and psychiatric symptoms such as rage behaviors. MR imaging on patients with epilepsy typically shows attachment of the HH in a posterior location in the hypothalamus, in the region of the mammillary bodies. Approximately 40% of HH patients with epilepsy also have precocious puberty. These patients tend to have larger lesions, which are broadly attached both anteriorly and posteriorly in the hypothalamus.
Anti-epilepsy medications usually do not control the gelastic seizures associated with HH, and seizures often worsen with additional seizures types that begin around 4-7 years of age. Cognitive deficits and psychiatric symptoms may also present at this time. For some patients, HH can be a progressively disabling condition. For others, symptoms may be stable and represent little or no disability.

Patients with precocious puberty can usually be treated successfully with medications, specifically with a class of drugs known as gonadotropin-releasing hormone agonists. Medications, specifically anti-epilepsy drugs (AEDs) are less successful for controlling the seizures associated with HH, and therefore surgical intervention may be needed. There has been rapid progress over the past 10 years on developing various surgical approaches for treating HH. The selection of the most appropriate surgical technique is individualized to the clinical symptoms and HH anatomy of each patient.

Organizations related to Hypothalamic Hamartoma

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