Electroencephalography is used to find the source of electrical activity causing the gelastic seizure. The classic presentation is gelastic or laughing epilepsy, a disorder characterized by spells of involuntary laughter with interval irritability and depressed mood. The tumor can be associated with other seizure types as well as precocious<unk> ty and behavioral disorders. Gelastic epilepsy has been more classically associated with sessile lesions and precocious<unk> ty reported with pedunculated morphology. More recent epidemiologic studies have found these associations to be less consistent, with gelastic epilepsy predominant in the majority of patients regardless of morphology. Hypothalamic hamartomas are found in 33% of patients with true precocious<unk> ty. The etiology of this relationship is unclear, but it is suspected in some cases to be due to a nonphysiological secretion of GnRH. A case of hamartoma has also been reported to secrete CRH, causing excessive ACTH production. Seizures often begin when patients are young, although studies have shown adult onset as well. Many causes of the epilepsy have been theorized, with EEG often finding the hamartoma itself as the source of electrical activity, or epileptogenic focus. With chronic seizures, cognitive decline can develop, which can manifest as poor school performance, decreased nervous stimulus IQ, or limited socialization. Other symptoms of this tumor type include visual disturbances, such as the appearance of motion from a stationary object, or inappropriate color perception of the entire visual field. Associated conditions<unk>  may be associated with Pallister-Hall syndrome, a diagnosis characterized by multiple malformations, including polydactyly and imperforate anus. Neurologic symptoms are less severe in Pallister-Hall than in isolated cases of hamartoma.
Tuber cinereum hamartoma
Eruptive vellus hair cyst
Ectodermal dysplasia with corkscrew hairs
Rathke's cleft cyst
Ganglion cyst
Trichofolliculoma
Neuroma cutis
Fibrous hamartoma of infancy