Petrosal Sinus Sampling and Corticotropin-Releasing Hormone in Cushingʼs Syndrome

Abstract

: Approximately 5% of patients with proven Cushing's disease have nomdiagnostic inferior petrosal sinus (IPS) samples before corticotropinreleasing hormone (CRH) stimulation, presumably due to the cyclic function of the corticotropin adenoma. Because this 5% cannot be predicted, CRH stimulation is essential in all patients undergoing petrosal sinus sampling. Studies on the efficacy of CRH stimulation in lateralization show that, aside from the 5% of patients who require CRH stimulation to produce a positive study result, CRH stimulation has little influence on the accuracy of lateralization. To offset the unavailability of CRH before synthetic CRH was approved for clinical use, cavernous sinus (CS) sampling has been proposed as an alternative to IPS sampling. The results of our studies comparing the accuracy of CS sampling with IPS sampling show that with the availability of CRH stimulation there is no advantage to CS sampling. In fact, it increases costs. Preliminary results with internal jugular vein sampling are presented. This is a less invasive procedure than IPS sampling and requires CRH stimulation for reliable results. (C) Lippincott-Raven Publishers.