The Hypothalamus

The hypothalamus plays a key role in regulation of endocrine (pituitary function), metabolic (food intake, energy balance, and water metabolism), and nonendocrine (body temperature, sleep/wake cycle) functions. Diseases involving the hypothalamus give rise to variable associations of endocrine, metabolic, neurologic, and other systemic signs and symptoms. Causes of hypothalamic dysfunction include genetic diseases such as Prader-Willi and Bardet-Biedl syndromes, neoplastic lesions (e.g., craniopharyngioma) or hematologic systemic disorders such as sarcoidosis and Langerhans' cell histiocytosis, traumatic, and postirradiation brain disorders. Due to the pivotal role of the hypothalamus in regulation of food intake, obesity is a common finding in patients with hypothalamic disorders or in those undergoing hypothalamic-pituitary surgery.