I saw an interesting case today. It was a child with a hypothalamic hamartoma, a tumor (likely present from birth or shortly thereafter) right on the midline of the brain by the hypothalamus and the third ventricle. These tumors are quite rare and result in some interesting behaviors. A common result of these hamartomas is what is called precocious puberty – very early puberty onset; this early puberty often occurs before age 2. This can occur because the hypothalamus is one of the major brain areas that creates hormones and modulates the endocrine system.
Another common result of these hamartomas is gelastic seizures. Gelastic seizures are laughing seizures. The seizure manifests with the child (or adult) having sudden laughing fits for no apparent reason. They can occur many times a day. Some people also have dacrystic seizures, or crying seizures. Developmental delays are also common in this type of brain disorder as is hyperactive behavior.
Hypothalamic hamartomas are sometimes treatable by resection. This surgery has the possibility of eliminating the seizures and stopping most or all of the hormonal abnormalities.