Table 1 Neuroendocrine changes in acute traumatic brain injury.

Study	Number	Time to testing	GCS score	Test used	Neuroendocrine axis assessed
Study	Number	Time to testing	GCS score	Test used	Adrenal	GH	Thyroid	Gonadal	Prolactin
Feibel,20 1983	23	12–36 h	<8	Basal ACTH + cortisol	↑Cortisol despite ↑ dose dexamethasone	N/A	N/A	N/A	N/A
Hackl,21 1991	21	Acute phase	<6 or >6	Basal, TRH + arginine stimulation	↑ Cortisol	Impaired response to arginine stimulation	↑ T4	N/A	Low
Della Corte,22 1998	22	Day 1–5, Day 15+16	4–8	Basal, GHRH + TRH stimulation	↓ Cortisol day 2–7	↑ IGF-1 day 7+15 Exaggerated GH response to GHRH	TSH+T4 normal T3 low	N/A	Unchanged
Cernak,23 1999	18/31	7 days	13–15 (n = 8) Closed injury	Basal	↑ Cortisol day 1+2	N/A	↑TSH day 1–3, ↑T3 day 1,5,7, T4 unchanged	↓Testosterone	N/A
Cernak,23 1999	18/31	7 days	4–6 (n = 10) Penetrating injury	Basal	↓ Cortisol day 1–3, ↑ Cortisol day 5–7	N/A	↓TSH day 1–7, ↓T3 day 1–7, T4 unchanged	↓Testosterone day 1–7	N/A
Agha,24 2004	50	12 days median	3–13	Basal + GST	16% deficient	18% deficient	2% deficient	80% deficient	52% high
Cohan,25 2005	80	1–9 days	3–13	ACTH + cortisol	53% insufficient	N/A	N/A	N/A	N/A
Tanriverdi,26 2006	52	24 h	3–15	Basal	9.8% deficient	20.4% deficient	5.8% deficient	41.6% deficient	12% high

ACTH, adrenocorticotropin hormone; GCS, Glasgow Coma Scale; GH, growth hormone; GHRH, growth-hormone-releasing hormone; GST, glucagon stimulation test; IGF-1, insulin-like growth factor 1; N/A, not available; T3, triiodothyronine; T4, thyroxine; TRH, thyrotropin-releasing hormone; TSH, thyroid-stimulating hormone.