In a prospective study of 49 patients with SAH, Tsubokawa et al. observed that theplasma ANF concentrations were not altered.(33) Normal ANF plasma levels have been found in patients withCSWS associated with parietal glioma(11) and after surgery for pituitary adenoma.(34) During experimental natriuresisinduced by the intracerebroventricular administration of hypertonic saline, plasmaANF levels were found to decrease.(35). Here, NPPA is linked to pituitary gland adenoma.