title: Prevalence of hypopituitarism after intracranial operations not directly associated with the pituitary gland.
abstract: BACKGROUND
  Over the last few years, awareness and detection rates of hypopituitarism following traumatic brain injury (TBI) and subarachnoid hemorrhage (SAH) has steadily increased. Moreover, recent studies have found that a clinically relevant number of patients develop pituitary insufficiency after intracranial operations and radiation treatment for non-pituitary tumors. But, in a substantial portion of more than 40%, the hypopituitarism already exists before surgery. We sought to determine the frequency, pattern, and severity of endocrine disturbances using basal and advanced dynamic pituitary testing following non-pituitary intracranial procedures.
  
  
  METHODS
  51 patients (29 women, 22 men) with a mean age of 55 years (range of 20 to 75 years) underwent prospective evaluation of basal parameters and pituitary function testing (combined growth hormone releasing hormone (GHRH)/arginine test, insulin tolerance test (ITT), low dose adrenocorticotropic hormone (ACTH) test), performed 5 to 168 months (median 47.2 months) after intracranial operation (4 patients had additional radiation and 2 patients received additional radiation combined with chemotherapy).
  
  
  RESULTS
  We discovered an overall rate of hypopituitarism with distinct magnitude in 64.7% (solitary in 45.1%, multiple in 19.6%, complete in 0%). Adrenocorticotropic hormone insufficiency was found in 51.0% (partial in 41.2%, complete in 9.8%) and growth hormone deficiency (GHD) occurred in 31.4% (partial in 25.5%, severe in 5.9%). Thyrotropic hormone deficiency was not identified. The frequency of hypogonadism was 9.1% in men. Pituitary deficits were associated with operations both in close proximity to the sella turcica and more distant regions (p = 0.91). Age (p = 0.76) and gender (p = 0.24) did not significantly differ across patients with versus those without hormonal deficiencies. Groups did not significantly differ across pathology and operation type (p = 0.07).
  
  
  CONCLUSIONS
  Hypopituitarism occurs more frequently than expected in patients who have undergone neurosurgical intracranial procedures for conditions other then pituitary tumors or may already exists in a neurosurgical population before surgery. Pituitary function testing and adequate substitution may be warranted for neurosurgical patients with intracranial pathologies at least if unexplained symptoms like fatigue, weakness, altered mental activity, and decreased exercise tolerance are present.
authors.affiliation: Department of Neurosurgery, University Medicine Greifswald, Ferdinand-Sauerbruch-Strasse, 17475 Greifswald, Germany. sfleck@uni-greifswald.de.
authors.forename: Steffen Kristian
authors.initials: SK
authors.lastname: Fleck
authors.forename: Henri
authors.initials: H
authors.lastname: Wallaschofski
authors.forename: Christian
authors.initials: C
authors.lastname: Rosenstengel
authors.forename: Marc
authors.initials: M
authors.lastname: Matthes
authors.forename: Thomas
authors.initials: T
authors.lastname: Kohlmann
authors.forename: Matthias
authors.initials: M
authors.lastname: Nauck
authors.forename: Henry Werner Siegfried
authors.initials: HW
authors.lastname: Schroeder
authors.forename: Christin
authors.initials: C
authors.lastname: Spielhagen