[Endocrinological Tests for Neurosurgery Practice]

Endocrinological evaluation is essential in neurosurgery for pituitary-hypothalamic disorders and intracranial conditions, such as tumors, trauma, hemorrhagic/ischemic events, inflammatory diseases, and iatrogenic injuries. Appropriate selection and interpretation of hormonal tests influence diagnosis, treatment strategies, perioperative care, and long-term outcomes. Baseline assessments should include measurements of anterior pituitary hormones (ACTH, TSH, GH, LH/FSH, and prolactin) and their corresponding peripheral hormones (cortisol, free thyroxine, IGF-1, and sex steroids). Because adrenal insufficiency is life-threatening, the ACTH-cortisol axis must be prioritized, with thyroid hormone replacement initiated only after adrenal function is confirmed. If baseline tests are inconclusive, dynamic stimulation tests are used to evaluate each axis; however, test selection must consider safety, as some stimulation tests are associated with rare complications, such as pituitary apoplexy, in patients with large Pit-NETs. This review summarizes the practical aspects of endocrine testing that are relevant to neurosurgeons, including typical endocrine profiles in intracranial diseases, indications and pitfalls of stimulation tests, and perioperative monitoring and hormone replacement, in collaboration with endocrinologists.