Hypopituitarism following Severe Traumatic Brain Injury

Abstract

Although hypopituitarism is a known complication of traumatic head injury, it may be under-recognized due to its subtle clinical manifestations. To address this issue, we determine the prevalence of neuroendocrine abnormalities in patients rehabilitating from severe traumatic brain injury (Glasgow Coma Scale < or = 8). 76 patients (mean age 39 +/- 14 yr; range 18-65; 53 males and 23 females; BMI 25.8 +/- 4.2 kg/m2; mean +/- SD) with a severe traumatic brain injury, an average of 22 +/- 10 months before this study (median, 20 months), underwent a series of standard endocrine tests, including TSH, free T4, T4, T3, prolactin, testosterone (males), estradiol (females), cortisol, ACTH, GH, and IGF-I. All subjects also underwent GH response to GHRH + arginine. Growth hormone deficiency (GHD) was defined as a GH response < 9 microg/L to GHRH + arginine and was confirmed by ITT (< 3 microg/L). Pituitary deficiency was shown in 24% of the patients (18/76). 8% (n = 6) had GHD (GH-peak range [GHRH + arginine]: 2.8-6.3 microg/L; GH-peak range [ITT]: 1.5-2.2 microg/L; IGF-I range: 62-174 microg/L). 17% (n = 13) had hypogonadism (total testosterone < 9.5 nmol/L and low gonadotropins in 12 males; low estradiol, and low gonadotropins in 1 female). Total testosterone levels did not correlate with BMI or age. 2 males with hypogonadism also showed a mild hyperprolactinemia (33 and 41 ng/ml). 3% (n = 2) patients had partial ACTH-deficiency (cortisol-peak [ITT] 392 and 417 nmol/L) and 3% (n = 2) had TSH-deficiency. In summary, we have found hypopituitarism in one-fourth of patients with predominantly secondary hypogonadism and GHD. These findings strongly suggest that patients who suffer head trauma must routinely include neuroendocrine evaluations.

Low prevalence of hypopituitarism after traumatic brain injury: a multicenter study

“…This prevalence of hypopituitarism is much lower compared with the prevalence rates reported in the majority of the previous studies (15-90%) (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18). This might be explained by the use of different endocrine tests and cutoff values (19).…”

“…The available cohort studies investigating the prevalence of pituitary insufficiency report a percentage ranging from 15 to 90% (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18). There are several explanations for this remarkably wide range in reported prevalence, including differences in inclusion criteria and duration of follow-up since TBI (short-versus longterm follow-up), and the use of different tests, and cutoff values (19).…”

Hypopituitarism following brain injury: when does it occur and how best to test?

“…Kelly and colleagues emphasized that also patients with subarachnoid haemorrhage (SAH) may also be at high risk for consequent hypopituitarism [12]. Following these, other important retrospective studies evaluated patients who had experienced brain injury more than a year before [13,17,18,[21][22][23][24], others tested patients early after TBI or SAH [13,[21][22][23][24]. The clinical relevance of brain-injury-induced pituitary dysfunction was underlined by all authors.…”

“…Ten systematic studies of endocrine function in a total of 749 patients in the chronic phase after admission for TBI (most patients were studied at least 6 months after trauma) [12][13][14][15][16][17][18][19][20][21] and five studies of 122 individuals with aneurysmal SAH [12,[22][23][24][25] have been published. The different prevalence of hypopituitarism reported in the above mentioned studies is probably due to the different study design (cross sectional vs prospective studies), the different time of evaluation after BI (from 24 h to 23 years), and the different protocol used to investigate hypopituitarism.…”

On Treating Athletes with Banned Substances: The Relationship Between Mild Traumatic Brain Injury, Hypopituitarism, and Hormone Replacement Therapy

“…However, recent evidence suggests that these two problems may actually interact in complex and previously underappreciated ways. 1 A body of recent research has shown that TBIs, at all ranges of severity, have a negative effect upon pituitary function, which results in diminished levels of several endogenous Neuroethics DOI 10.1007/s12152-014-9215-2 hormones, such as growth hormone (GH) and gonadotropin [1][2][3][4][5][6][7][8]. Furthermore, emerging research suggests that hormone replacement therapy (HRT) is an effective treatment for symptoms caused by TBI-related hormone deficiency [9][10][11][12].…”