Dissociated patterns of nocturnal prolactin, cortisol, and growth hormone secretion after stroke

The secretory activity of the hypothalamic-pituitary axis is influenced by suprahypothalamic regulatory mechanisms. To evaluate the effect of brain lesions on hormonal patterns, we investigated eight patients convalescing from hemispheric stroke and five sex- and age-matched healthy volunteers. Studies were conducted during two consecutive nights with continuous polygraphic recording and sequential blood sampling. Nocturnal plasma hormone measurements showed a normal rhythm of cortisol (a marker of ACTH), elevated prolactin concentrations (p less than 0.05) and low growth hormone values (p less than 0.05). The study suggests that major suprahypothalamic lesions influence hypothalamic function so as to facilitate prolactin secretion and inhibit growth hormone release. They have no effect on the more basic pattern of ACTH-cortisol secretion, however.