Hypothalamic-hypopituitarism due to temporal arteritis

Hypothalamic hypopituitarism developed in a 74-year-old woman who was in the active phase of temporal arteritis. Hypopituitarism was established by low basal gonadotrophin, thyroxine, and thyroid-stimulating hormone levels. The failure of growth hormone and prolactin to respond to insulin hypoglycemia and an inadequate prolactin response to the administration of chlorpromazine provided further evidence of hypopituitarism. The hypothalamic origin of the hypopituitarism was suggested by quantitatively normal prolactin and gonadotrophin responses to the administration of gonadorelin (gonadotrophin-releasing hormone) and protirelin (thyrotrophin-releasing hormones). Despite the frequency of other intracranial neurological lesions, injury to the hypothalamus and pituitary gland is rare in temporal arteritis. This apparent protection may be due to the abundant blood supply to the hypothalamic-pituitary region.