You are reading a NORD Rare Disease Report Abstract. NORD’s full collection of reports on over 1200 rare diseases is available to subscribers (click here for details). We are now also offering two full rare disease reports per day to visitors on our Web site.
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
- central precocious puberty
- epilepsy and related neurobehavioral symptoms
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.
Hypothalamic Hamartoma Resources
NORD Member Organizations:
(To become a member of NORD, an organization must meet established criteria and be approved by the NORD Board of Directors. If you're interested in becoming a member, please contact Susan Olivo, Membership Manager, at email@example.com.)
The information in NORD’s Rare Disease Database is for educational purposes only. It should never be used for diagnostic or treatment purposes. If you have questions regarding a medical condition, always seek the advice of your physician or other qualified health professional. NORD’s reports provide a brief overview of rare diseases. For more specific information, we encourage you to contact your personal physician or the agencies listed as “Resources” on this report.
The National Organization for Rare Disorders (NORD) web site, its databases, and the contents thereof are copyrighted by NORD. No part of the NORD web site, databases, or the contents may be copied in any way, including but not limited to the following: electronically downloading, storing in a retrieval system, or redistributing for any commercial purposes without the express written permission of NORD. Permission is hereby granted to print one hard copy of the information on an individual disease for your personal use, provided that such content is in no way modified, and the credit for the source (NORD) and NORD’s copyright notice are included on the printed copy. Any other electronic reproduction or other printed versions is strictly prohibited.
NORD's Rare Disease Information Database is copyrighted and may not be published without the written consent of NORD.