A hypothalamic hamartoma is a noncancerous tumor that is attached to the hypothalamus gland in the brain. The hypothalamus is small in size. But it impacts many important body functions related to growth, behavior and sexuality.

Hypothalamic hamartomas are rare. They affect about one in 200,000 children and teenagers. The tumor is present when the child is born. Symptoms usually do not appear right after birth. The tumor grows as the normal brain grows. It does not spread to other locations.

Hypothalamic Hamartoma Causes

The exact cause of a hypothalamic hamartoma is unknown. Some studies suggest that changes in the GL13 gene may be responsible. Only about 5% of patients have a family history of the condition.

Hypothalamic Hamartoma Symptoms

Hypothalamic hamartomas affect each patient differently. Symptoms depend on the size of the tumor and where it is located on the hypothalamus. Patients may have one or more of the following:

  • Frequent seizures. At first, these include short gelastic seizures (looking like sudden, forced laughter) or dacrystic seizures (looking like sudden, forced crying). But over time, different types of seizures occur. These may be absence or complex partial and generalized seizures. These seizures often get worse as the child grows older.
  • Cognitive impairments (problems with memory, mental processing).
  • Fits of rage and other emotional and behavioral difficulties.
  • Physical signs of early puberty (as early as infancy, but always before age 8 for girls and age 9 for boys). When a child with a hypothalamic hamartoma has precocious (early) puberty, seizures and other neurological problems are not as common.

Conditions Associated with a Hypothalamic Hamartoma

Some patients with a hypothalamic hamartoma have a rare genetic condition called “Pallister-Hall syndrome.” Pallister-Hall syndrome affects the development of many parts of the body. For example, a person may have abnormal facial features, an abnormal larynx (voice box) or extra fingers and/or toes. The skin between some fingers or toes may be fused. Patients with Pallister-Hall syndrome may not have seizures.

Hypothalamic Hamartoma Diagnosis

Diagnosing a hypothalamic hamartoma is challenging. These tumors can be hard to detect because they are located deep within the brain. They can be small. Also, the type of seizures that patients have at first can be subtle. They are often attributed to colic, acid reflux or irritable bowel syndrome.

Working with a medical team that has a great deal of experience in treating this condition is essential. Early diagnosis can improve the likelihood of a successful outcome. Without it, a child’s condition could get worse. They could lose cognitive (thinking) skills that cannot be regained.

Diagnosing a hypothalamic hamartoma involves a physical exam, neurological tests and medical imaging. Magnetic resonance imaging (MRI) is the best way for doctors to confirm the presence of a hypothalamic hamartoma.

Hypothalamic Hamartoma Treatment

Seizures do not respond well to anti-seizure medications. The alternative seizure treatment option is surgery to disconnect the tumor from the part of the brain that causes seizures in this region.

Hypothalamic Hamartoma Prognosis

Some patients who have a hypothalamic hamartoma can have symptoms that get worse and worse. Others have very little disability.

When a child has seizures that are caused by a hypothalamic hamartoma, their condition tends to get worse over time. The seizures become longer and more involved. More seizure types develop. Infants may have delays in speech, coordination and walking. Older children may have unprovoked rage attacks. They may also have social and academic problems.

Patients who have precocious puberty but do not have seizures typically do not have developmental, behavioral or cognitive deficits.