Methopyrapone Tests in Hypothalamic-Pituitary Disease

Abstract

This study was designed to investigate the efficacy of the methopyrapone test in disclosing possible abnormalities in ACTH release in patients with central nervous system or pituitary disease who exhibited little or no endocrine impairment. Methopyrapone tests were carried out in 10 patients with primarily hypothalamic disease, and in 14 patients with sellar tumors presenting with primarily visual symptoms. Positive (normal) responses were obtained in 8 of 10 patients with hypothalamic disease and in 10 of 14 patients with pituitary disease. The findings in the patients with hypothalamic disease are in general agreement with other reported series. In contrast, the proportion of positive responses in the pituitary cases is higher than that in previously reported studies. This difference may reflect the absence of prior therapy (surgery or irradiation) to the pituitary area, and /or the lower incidence of endocrinopathy in our patients. In view of these findings, the value of the methopyrapone test in assessing “pituitary reserve” in essentially endocrinologically normal subjects may thus be questioned.