Pituitary hormone response to head injury.

Measurements of the serum levels of pituitary hormones were made in six patients with uncomplicated head injury. Samples were obtained at 4-hour intervals for 72 hours to evaluate diurnal rhythms. Three of the six patients revealed elevations of serum growth hormone (GH) and prolactin, but no trends could be established. Likewise, three patients had marked elevations of luteinizing hormone and lesser elevations of follicle-stimulating hormone, but no pattern was discernible. The level of thyroid-stimulating hormone was stable and remained in the normal range throughout. GH was measured after intravenous glucose loading. A paradoxical rise reverted to normal at the late follow-up evaluation. It is suggested that the abnormal levels were related to abnormal hypothalamic function rather than to pituitary damage.