Neuroendocrine Disorders

Abstract

The brain participates in the endocrine system through the hypothalamus, which contains the neurosecretory system that produces releasing hormones. Some of these hormones are secreted into the hypothalamohypophysial portal system to regulate anterior pituitary hormones and others into the general circulation in the posterior pituitary to control water conservation and breast milk ejection. The hypothalamus and its connections with the anterior and posterior pituitary gland comprise the hypothalamic-pituitary unit [1,2] (Fig. 3-2). The hypothalamus regulates additional vegetative and autonomic functions, including eating, drinking, and temperature. Lesions in or around the hypothalamic-pituitary unit cause various clinical syndromes in the endocrine system associated with decreased or increased hormonal secretions. Tumors in or around the hypothalamus also produce other vegetative symptoms and involve other neural structures nearby; the optic nerves and chiasm are particularly vulnerable. At times extension into the cavernous sinus causes eye movement difficulties. Occasionally obstruction of the third ventricle and its outflow result in hydrocephalus. Headache can be caused by traction on the pain-sensitive dura of the diaphragm of the sella.