This study performs assessments of pituitary functions by basal hormone levels in the acute phase after TBI and/or SAH followed by detailed endocrine tests (insulin-induced hypoglycemia or growth hormone releasing hormone-arginine-corticotropin releasing hormone-leuteinizing hormone releasing hormone \[GHRH-arginine-CRH-LHRH\] test) after 4 and 12 months.

Recent data have demonstrated that hypopituitarism seems to be a frequent finding after traumatic brain injury (TBI) and/or subarachnoid hemorrhage (SAH). However, most of these studies referred to retrospective evaluations. There are only few prospective data, and no longitudinal study routinely taking into account the assessment of anterior pituitary function in the acute phase after TBI or SAH so far. We prospectively evaluate pituitary functions in patients in the acute phase after TBI or SAH and a control group of patients with trauma not involving the brain. Endocrine data included basal anterior pituitary lobe hormone, IGF-1 and testosterone serum levels (Immulite 2000) within the first 8 hours after TBI or SAH. Further endocrine evaluation was performed by means of either a combined GHRH-arginine-CRH-LHRH test or an insulin-induced hypoglycemia test after 4 months and 12 months. To rule out an assay related bias with regard to GH and IGF-1, all hormone levels were cross-checked by a supersensitive assay in another laboratory.