Loss of adrenocortical suppression after acute brain injury: role of increased intracranial pressure and brain stem function

J Clin Endocrinol Metab. 1983 Dec;57(6):1245-50. doi: 10.1210/jcem-57-6-1245.

Abstract

The function of the pituitary-adrenal axis was studied in 23 acutely brain-injured, comatose patients (14 head trauma and 9 intracranial hemorrhage), who were treated with dexamethasone (16-64 mg/daily). Patients with normal intracranial pressure (ICP) and normal brain stem function (group 1) had decreased plasma cortisol levels (less than or equal to 5 micrograms/dl) within 36 h (mean +/- SEM, 2.4 +/- 0.3 microgram/dl; t 1/2, 18 h). In contrast, patients with elevated ICP (i.e. greater than 20 mm Hg; midline shift, or compressed ventricles) and normal brain stem function (group 2) had persistently elevated cortisol concentrations (15.4 +/- 2.6 micrograms/dl; P less than 0.001). Superimposition of brain stem dysfunction resulted in generally low cortisol levels regardless of the presence (group 4; 3.9 +/- 1.0 microgram/dl; P less than 0.001 compared to group 2) or absence (group 3; 2.1 +/- 0.5 microgram/dl) of elevated ICP. Plasma ACTH levels in 31 samples obtained before or during dexamethasone therapy in 14 patients irrespective of group were not elevated (45.6 +/- 12.5 pg/ml); there was no correlation between plasma ACTH and cortisol levels. Despite elevated cortisol values in group 2, ACTH levels were low (22.4 +/- 10.1 pg/ml). It is concluded that elevated ICP in the presence of normal brain stem function is a potent stimulus for adrenocortical activation which is not associated with elevated ACTH levels, and that the brain stem is involved in this response.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adrenal Cortex / physiopathology*
  • Adrenocorticotropic Hormone / blood
  • Adult
  • Brain Injuries / physiopathology*
  • Brain Stem / physiopathology*
  • Dexamethasone
  • Female
  • Humans
  • Hydrocortisone / blood*
  • Intracranial Pressure*
  • Kinetics
  • Male
  • Middle Aged

Substances

  • Dexamethasone
  • Adrenocorticotropic Hormone
  • Hydrocortisone