Hypogonadism on admission to acute rehabilitation is correlated with lower functional status at admission and discharge

Multifetal gestations after traumatic brain injury: a nationwide register-based cohort study in Finland

BACKGROUND

There is a paucity of information regarding the association between traumatic brain injuries (TBIs) and subsequent multifetal gestations. Since TBIs are known to negatively affect the neuroendocrine system, we hypothesized that the functions of the whole reproductive system might be disturbed as a result. The aim of this study is to determine the association between previous TBIs and the risk of multifetal gestations using nationwide registers.

METHODS

In this retrospective register-based cohort study, data from the National Medical Birth Register (MBR) were combined with data from the Care Register for Health Care. All fertile-aged women (15-49 years) who had sustained a TBI before pregnancy were included in the patient group. Women with prior fractures of the upper extremity, pelvis, and lower extremity were included in the control group. A logistic regression model was used to assess the risk for multifetal gestation after TBI. Odds ratios (ORs) and adjusted odds ratios (aOR) with 95% confidence intervals (CIs) between the groups were compared. The model was adjusted by maternal age and maternal BMI during pregnancy and previous births. The risk for multifetal gestations were evaluated during different periods following the injury (0-3 years, 3-6 years, 6-9 years, and 9 + years).

RESULTS

A total of 14 153 pregnancies occurred after the mother had sustained a TBI, and 23 216 pregnancies occurred after the mother had sustained fractures of the upper extremity, pelvis, or lower extremity. Of these, 201 (1.4%) women had multifetal gestations after TBI and 331 (1.4%) women had multifetal gestations after fractures of the upper extremity, pelvis, or lower extremity. Interestingly, the total odds of multifetal gestations were not higher after TBI when compared to fractures of the upper extremity, pelvis, and lower extremity (aOR 1.04, CI 0.86-1.24). The odds were highest at 6-9 years (aOR 1.54, 1.03-2.29) and lowest at 0-3 years (aOR 0.84, CI 0.59-1.18).

CONCLUSION

The risk for multifetal gestations after TBIs was not higher than after the other traumas included in this study. Our results provide good baseline information on the effects of TBIs on the risk for multifetal gestations, but further research is required on this topic.

A Systematic Review of Testosterone Therapy in Men With Spinal Cord Injury or Traumatic Brain Injury

Spinal cord injuries (SCI) and traumatic brain injuries (TBI) increase the risk of testosterone deficiency and result in adverse changes in body composition and poor functional outcomes. The current systematic review aims to provide insights into the use of testosterone therapy for treating men with SCI and TBI. The PubMed and EMBASE databases were systematically reviewed using appropriate terms, and resulting manuscripts were screened using defined Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. The patient population included male patients with SCI or TBI. Further inclusion criteria were: a) human participants 18 years of age or older; b) manuscript published in English; c) study included an intervention with exogenous testosterone; and d) articles published in peer-reviewed journals with full text available. Two reviewers independently extracted data regarding injury type, intervention, and outcomes. Following screening for inclusion/exclusion criteria, a total of 12 primary research studies conducted over the last 30 years were included. Men with SCI were investigated in 11 articles. The combination of testosterone patches and resistance training with functional electrical stimulation (FES) for 16 weeks in men with SCI and an average baseline testosterone level above the cutoff for testosterone deficiency increased muscle mass, strength, bone quality, and basal metabolic rate while testosterone patches without exercise for 16 weeks produced no significant changes in these parameters. Testosterone patches for 12 months in men with SCI and testosterone deficiency also increased lean tissue mass (LTM) and resting energy expenditure (REE). In one study, men with TBI and testosterone deficiency receiving testosterone gel for eight weeks showed a non-statistically significant greater absolute change in functional independence measure (FIM) and grip strength compared to a placebo group. Testosterone therapy with exercise may help improve muscle mass, bone health, strength, energy expenditure, and cardiac health in men with SCI without major side effects. It is difficult to draw conclusions regarding the effects of testosterone therapy in men with TBI based on the limited available evidence. Further investigation is warranted to explore the relationship between testosterone therapy and recovery after SCI and TBI.

Hypogonadism induced by surgical stress and brain trauma is reversed by human chorionic gonadotropin in male rats: A potential therapy for surgical and TBI-induced hypogonadism?

INTRODUCTION

Hypogonadotropic hypogonadism (HH) is an almost universal, yet underappreciated, endocrinological complication of traumatic brain injury (TBI). The goal of this study was to determine whether the developmental hormone human chorionic gonadotropin (hCG) treatment could reverse HH induced by a TBI.

METHODS

Plasma samples were collected at post-surgery/post-injury (PSD/PID) days -10, 1, 11, 19 and 29 from male Sprague-Dawley rats (5- to 6-month-old) that had undergone a Sham surgery (craniectomy alone) or CCI injury (craniectomy + bilateral moderate-to-severe CCI injury) and treatment with saline or hCG (400 IU/kg; i.m.) every other day.

RESULTS

Both Sham and CCI injury significantly decreased circulating testosterone (T), 11-deoxycorticosterone (11-DOC) and corticosterone concentrations to a similar extent (79.1% vs. 80.0%; 46.6% vs. 48.4%; 56.2% vs. 32.5%; respectively) by PSD/PID 1. hCG treatment  returned circulating T to baseline concentrations by PSD/PID 1 (8.9 ± 1.5 ng/ml and 8.3 ± 1.9 ng/ml; respectively) and was maintained through PSD/PID 29. hCG treatment significantly, but transiently, increased circulating progesterone (P4) ~3-fold (30.2 ± 10.5 ng/ml and 24.2 ± 5.8 ng/ml) above that of baseline concentrations on PSD 1 and PID 1, respectively. hCG treatment did not reverse hypoadrenalism following either procedure.

CONCLUSIONS

Together, these data indicate that (1) craniectomy is sufficient to induce persistent hypogonadism and hypoadrenalism, (2) hCG can reverse hypogonadism induced by a craniectomy or craniectomy +CCI injury, suggesting that (3) craniectomy and CCI injury induce a persistent hypogonadism by decreasing hypothalamic and/or pituitary function rather than testicular function in male rats. The potential role of hCG as a cheap, safe and readily available treatment for reversing surgery or TBI-induced hypogonadism is discussed.

The Role of Estradiol in Traumatic Brain Injury: Mechanism and Treatment Potential

Patients surviving traumatic brain injury (TBI) face numerous neurological and neuropsychological problems significantly affecting their quality of life. Extensive studies over the past decades have investigated pharmacological treatment options in different animal models, targeting various pathological consequences of TBI. Sex and gender are known to influence the outcome of TBI in animal models and in patients, respectively. Apart from its well-known effects on reproduction, 17β-estradiol (E2) has a neuroprotective role in brain injury. Hence, in this review, we focus on the effect of E2 in TBI in humans and animals. First, we discuss the clinical classification and pathomechanism of TBI, the research in animal models, and the neuroprotective role of E2. Based on the results of animal studies and clinical trials, we discuss possible E2 targets from early to late events in the pathomechanism of TBI, including neuroinflammation and possible disturbances of the endocrine system. Finally, the potential relevance of selective estrogenic compounds in the treatment of TBI will be discussed.

Testosterone replacement in hypogonadal men during inpatient rehabilitation following traumatic brain injury: Results from a double-blind, placebo-controlled clinical pilot study

BACKGROUND

Endocrinopathy, including hypogonadism, is common following traumatic brain injury (TBI). Prior evidence suggests hypogonadism is associated with poorer function.

OBJECTIVE

Determine the feasibility, safety, and efficacy of testosterone (T) therapy in hypogonadal men following TBI in acute rehabilitation.

DESIGN

Randomized, double blind, placebo-controlled pilot trial.

SETTING

Inpatient rehabilitation brain injury unit.

PARTICIPANTS

Men ages 18 -65, post moderate to severe TBI receiving inpatient rehabilitation.

INTERVENTIONS

Transdermal T gel or placebo.

MAIN OUTCOME MEASURES

Revised FIM™ score, strength, adverse events.

RESULTS

Of 498 screened, 70 participants were enrolled, and 22 meeting all criteria were randomized into placebo (n = 10) or physiologic T therapy (n = 12). There was no significant difference between groups in rate of improvement on the FIM™ (intercepts t = -0.31, p = 0.7593, or slopes t = 0.61, p = 0.5472). The Treatment group demonstrated the greatest absolute improvement in FIM™ scores and grip strength compared to Placebo or Normal T groups. There was no difference in adverse events between groups. Percentage of time with agitation or aggression was highest in the Placebo group.

CONCLUSIONS

Although there were no significant differences in rates of recovery, treatment group subjects showed greater absolute functional and strength improvement compared to the Placebo or Normal T groups.

Anti-Pituitary and Anti-Hypothalamus Autoantibody Associations with Inflammation and Persistent Hypogonadotropic Hypogonadism in Men with Traumatic Brain Injury

Traumatic brain injury (TBI) and can lead to persistent hypogonadotropic hypogonadism (PHH) and poor outcomes. We hypothesized that autoimmune and inflammatory mechanisms contribute to PHH pathogenesis. Men with moderate-to-severe TBI (n = 143) were compared with healthy men (n = 39). The TBI group provided blood samples 1-12 months post-injury (n = 1225). TBI and healthy control (n = 39) samples were assayed for testosterone (T) and luteinizing hormone (LH) to adjudicate PHH status. TBI samples 1-6 months post-injury and control samples were assayed for immunoglobulin M (IgM)/immunoglobulin G (IgG) anti-pituitary autoantibodies (APA) and anti-hypothalamus autoantibodies (AHA). Tissue antigen specificity for APA and AHA was confirmed via immunohistochemistry (IHC). IgM and IgG autoantibodies for glial fibrillary acid protein (GFAP) (AGA) were evaluated to gauge APA and AHA production as a generalized autoimmune response to TBI and to evaluate the specificity of APA and AHA to PHH status. An inflammatory marker panel was used to assess relationships to autoantibody profiles and PHH status. Fifty-one men with TBI (36%) had PHH. An age-related decline in T levels by both TBI and PHH status were observed. Injured men had higher APA IgM, APA IgG, AHA IgM, AHA IgG, AGA IgM, and AGA IgG than controls (p < 0.0001 all comparisons). However, only APA IgM (p = 0.03) and AHA IgM (p = 0.03) levels were lower in the PHH than in the non-PHH group in multivariate analysis. There were no differences in IgG levels by PHH status. Multiple inflammatory markers were positively correlated with IgM autoantibody production. PHH was associated with higher soluble tumor-necrosis-factor receptors I/II, (sTNFRI, sTNFRII), regulated on activation, normal T-cell expressed and secreted (RANTES) and soluble interleukin-2-receptor-alpha (sIL-2Rα) levels. Higher IgM APA, and AHA, but not AGA, in the absence of PHH may suggest a beneficial or reparative role for neuroendocrine tissue-specific IgM autoantibody production against PHH development post-TBI.

Sex Differences in Traumatic Brain Injury: What We Know and What We Should Know

There is growing recognition of the problem of male bias in neuroscience research, including in the field of traumatic brain injury (TBI) where fewer women than men are recruited to clinical trials and male rodents have predominantly been used as an experimental injury model. Despite TBI being a leading cause of mortality and disability worldwide, sex differences in pathophysiology and recovery are poorly understood, limiting clinical care and successful drug development. Given growing interest in sex as a biological variable affecting injury outcomes and treatment efficacy, there is a clear need to summarize sex differences in TBI. This scoping review presents an overview of current knowledge of sex differences in TBI and a comparison of human and animal studies. We found that overall, human studies report worse outcomes in women than men, whereas animal studies report better outcomes in females than males. However, closer examination shows that multiple factors including injury severity, sample size, and experimental injury model may differentially interact with sex to affect TBI outcomes. Additionally, we explore how sex differences in mitochondrial structure and function might contribute to possible sex differences in TBI outcomes. We propose recommendations for future investigations of sex differences in TBI, which we hope will lead to improved patient management, prognosis, and translation of therapies from bench to bedside.

Experimental traumatic brain injury results in estrous cycle disruption, neurobehavioral deficits, and impaired GSK3β/β-catenin signaling in female rats

An estimated 2.8 million traumatic brain injuries (TBI) occur within the United States each year. Approximately 40% of new TBI cases are female, however few studies have investigated the effects of TBI on female subjects. In addition to typical neurobehavioral sequelae observed after TBI, such as poor cognition, impaired behavior, and somatic symptoms, women with TBI report amenorrhea or irregular menstrual cycles suggestive of disruptions in the hypothalamic-pituitary-gonadal (HPG) axis. HPG dysfunction following TBI has been linked to poor functional outcome in men and women, but the mechanisms by which this may occur or relate to behavior has not been fully developed or ascertained. The present study determined if TBI resulted in HPG axis perturbations in young adult female Sprague Dawley rats, and whether TBI was associated with cognitive and sensorimotor deficits. Following lateral fluid percussion injury, injured females spent significantly more time in diestrus compared to sham females, consistent with a persistent low sex-steroid hormone state. Injured females displayed significantly reduced 17β-estradiol (E2) and luteinizing hormone levels. Concomitantly, injured females were impaired in spatial working memory compared to shams. Impaired GSK3β/β-catenin signaling related to synaptic changes was evident one-week post-injury in the hippocampus among injured females compared to sham females, and this impairment paralleled the deficits in spatial working memory. Sensorimotor function, as evidenced by suppression of the acoustic startle response, was chronically impaired even after normal estrous cycling resumed. These data demonstrate that TBI results in estrous cycle impairments, memory dysfunction, and perturbations in GSK3β/β-catenin signaling, suggesting a potential mechanism for HPG-mediated cognitive impairment following TBI.

Persistent Hypogonadotropic Hypogonadism in Men After Severe Traumatic Brain Injury: Temporal Hormone Profiles and Outcome Prediction

OBJECTIVE

To (1) examine relationships between persistent hypogonadotropic hypogonadism (PHH) and long-term outcomes after severe traumatic brain injury (TBI); and (2) determine whether subacute testosterone levels can predict PHH.

SETTING

Level 1 trauma center at a university hospital.

PARTICIPANTS

Consecutive sample of men with severe TBI between 2004 and 2009.

DESIGN

Prospective cohort study.

MAIN MEASURES

Post-TBI blood samples were collected during week 1, every 2 weeks until 26 weeks, and at 52 weeks. Serum hormone levels were measured, and individuals were designated as having PHH if 50% or more of samples met criteria for hypogonadotropic hypogonadism. At 6 and 12 months postinjury, we assessed global outcome, disability, functional cognition, depression, and quality of life.

RESULTS

We recruited 78 men; median (interquartile range) age was 28.5 (22-42) years. Thirty-four patients (44%) had PHH during the first year postinjury. Multivariable regression, controlling for age, demonstrated PHH status predicted worse global outcome scores, more disability, and reduced functional cognition at 6 and 12 months post-TBI. Two-step testosterone screening for PHH at 12 to 16 weeks postinjury yielded a sensitivity of 79% and specificity of 100%.

CONCLUSION

PHH status in men predicts poor outcome after severe TBI, and PHH can accurately be predicted at 12 to 16 weeks.

Conjugated Linoleic Acid Administration Induces Amnesia in Male Sprague Dawley Rats and Exacerbates Recovery from Functional Deficits Induced by a Controlled Cortical Impact Injury

Long-chain polyunsaturated fatty acids like conjugated linoleic acids (CLA) are required for normal neural development and cognitive function and have been ascribed various beneficial functions. Recently, oral CLA also has been shown to increase testosterone (T) biosynthesis, which is known to diminish traumatic brain injury (TBI)-induced neuropathology and reduce deficits induced by stroke in adult rats. To test the impact of CLA on cognitive recovery following a TBI, 5-6 month old male Sprague Dawley rats received a focal injury (craniectomy + controlled cortical impact (CCI; n = 17)) or Sham injury (craniectomy alone; n = 12) and were injected with 25 mg/kg body weight of Clarinol® G-80 (80% CLA in safflower oil; n = 16) or saline (n = 13) every 48 h for 4 weeks. Sham surgery decreased baseline plasma progesterone (P4) by 64.2% (from 9.5 ± 3.4 ng/mL to 3.4 ± 0.5 ng/mL; p = 0.068), T by 74.6% (from 5.9 ± 1.2 ng/mL to 1.5 ± 0.3 ng/mL; p < 0.05), 11-deoxycorticosterone (11-DOC) by 37.5% (from 289.3 ± 42.0 ng/mL to 180.7 ± 3.3 ng/mL), and corticosterone by 50.8% (from 195.1 ± 22.4 ng/mL to 95.9 ± 2.2 ng/mL), by post-surgery day 1. CCI injury induced similar declines in P4, T, 11-DOC and corticosterone (58.9%, 74.6%, 39.4% and 24.6%, respectively) by post-surgery day 1. These results suggest that both Sham surgery and CCI injury induce hypogonadism and hypoadrenalism in adult male rats. CLA treatment did not reverse hypogonadism in Sham (P4: 2.5 ± 1.0 ng/mL; T: 0.9 ± 0.2 ng/mL) or CCI-injured (P4: 2.2 ± 0.9 ng/mL; T: 1.0 ± 0.2 ng/mL, p > 0.05) animals by post-injury day 29, but rapidly reversed by post-injury day 1 the hypoadrenalism in Sham (11-DOC: 372.6 ± 36.6 ng/mL; corticosterone: 202.6 ± 15.6 ng/mL) and CCI-injured (11-DOC: 384.2 ± 101.3 ng/mL; corticosterone: 234.6 ± 43.8 ng/mL) animals. In Sham surgery animals, CLA did not alter body weight, but did markedly increase latency to find the hidden Morris Water Maze platform (40.3 ± 13.0 s) compared to saline treated Sham animals (8.8 ± 1.7 s). In CCI injured animals, CLA did not alter CCI-induced body weight loss, CCI-induced cystic infarct size, or deficits in rotarod performance. However, like Sham animals, CLA injections exacerbated the latency of CCI-injured rats to find the hidden MWM platform (66.8 ± 10.6 s) compared to CCI-injured rats treated with saline (30.7 ± 5.5 s, p < 0.05). These results indicate that chronic treatment of CLA at a dose of 25 mg/kg body weight in adult male rats over 1-month 1) does not reverse craniectomy- and craniectomy + CCI-induced hypogonadism, but does reverse craniectomy- and craniectomy + CCI-induced hypoadrenalism, 2) is detrimental to medium- and long-term spatial learning and memory in craniectomized uninjured rats, 3) limits cognitive recovery following a moderate-severe CCI injury, and 4) does not alter body weight.

[Hypopituitarism following traumatic brain injury: diagnostic and therapeutic issues]

Traumatic Brain Injury (TBI) is a well-known public health problem worldwide and is a leading cause of death and disability, particularly in young adults. Besides neurological and psychiatric issues, pituitary dysfunction can also occur after TBI, in the acute or chronic phase. The exact prevalence of post-traumatic hypopituitarism is difficult to assess due to the wide heterogeneity of published studies and bias in interpretation of hormonal test results in this specific population. Predictive factors for hypopituitarism have been proposed and are helpful for the screening. The pathophysiology of pituitary dysfunction after TBI is not well understood but the vascular hypothesis is privileged. Activation of pituitary stem/progenitor cells is probably involved in the recovery of pituitary functions. Those cells also play a role in the induction of pituitary tumors, highlighting their crucial place in pituitary conditions. This review updates the current data related to anterior pituitary dysfunction after TBI and discusses the bias and difficulties encountered in its diagnosis.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY DISEASE STATE CLINICAL REVIEW: A NEUROENDOCRINE APPROACH TO PATIENTS WITH TRAUMATIC BRAIN INJURY

OBJECTIVE

Traumatic brain injury (TBI) is now recognized as a major public health concern in the United States and is associated with substantial morbidity and mortality in both children and adults. Several lines of evidence indicate that TBI-induced hypopituitarism is not infrequent in TBI survivors and may contribute to the burden of illness in this population. The goal of this article is to review the published data and propose an approach for the neuroendocrine evaluation and management of these patients.

METHODS

To identify pertinent articles, electronic literature searches were conducted using the following keywords: "traumatic brain injury," "pituitary," "hypopituitarism," "growth hormone deficiency," "hypogonadism," "hypoadrenalism," and "hypothyroidism." Relevant articles were identified and considered for inclusion in the present article.

RESULTS

TBI-induced hypopituitarism appears to be more common in patients with severe TBI. However, patients with mild TBI or those with repeated, sports-, or blast-related TBI are also at risk for hypopituitarism. Deficiencies of growth hormone and gonadotropins appear to be most common and have been associated with increased morbidity in this population. A systematic approach is advised in order to establish the presence of pituitary hormone deficiencies and implement appropriate replacement therapies.

CONCLUSION

The presence of traumatic hypopituitarism should be considered during the acute phase as well as during the rehabilitation phase of patients with TBI. All patients with moderate to severe TBI require evaluation of pituitary function. In addition, symptomatic patients with mild TBI and impaired quality of life are at risk for hypopituitarism and should be offered neuroendocrine testing.

Detection of Growth Hormone Deficiency in Adults with Chronic Traumatic Brain Injury

This study examined the prevalence of growth hormone deficiency (GHD) in patients with traumatic brain injury (TBI) during the post-acute phase of recovery and whether GHD was associated with increased disability, decreased independence, and depression. A secondary objective was to determine the accuracy of insulin-like growth factor-1 (IGF-1) levels in predicting GHD in patients with TBI. Anterior pituitary function was assessed in 235 adult patients with TBI through evaluation of fasting morning hormone levels. GH levels were assessed through provocative testing, specifically the glucagon stimulation test. GHD was diagnosed in a significant number of patients, with 45% falling into the severe GHD (≤3 μg/L) category. IGF-1 levels were not predictive of GHD. Patients with GHD were more disabled and less independent compared with those patients who were not GHD. Those patients with more severe GHD also showed decreased levels of cortisol and testosterone. Symptoms of depression were also more prevalent in this group. In addition, patients with severe GHD had delayed admission to post-acute rehabilitation. This study confirms the high prevalence of GHD in patients with TBI and the necessity to monitor clinical symptoms and perform provocative testing to definitively diagnose GHD.

Early endocrine alterations reflect prolonged stress and relate to 1-year functional outcome in patients with severe brain injury

OBJECTIVE

Severe brain injury may increase the risk of developing acute and chronic hypopituitarism. Pituitary hormone alterations developed in the early recovery phase after brain injury may have implications for long-term functional recovery. The objective of the present study was to assess the pattern and prevalence of pituitary hormone alterations 3 months after a severe brain injury with relation to functional outcome at a 1-year follow-up.

DESIGN

Prospective study at a tertiary university referral centre.

METHODS

A total of 163 patients admitted to neurorehabilitation after severe traumatic brain injury (TBI, n=111) or non-TBI (n=52) were included. The main outcome measures were endocrine alterations 3.3 months (median) after the brain injury and their relationship to the functioning and ability of the patients at a 1-year follow-up, as measured by the Functional Independence Measure and the Glasgow Outcome Scale-Extended.

RESULTS

Three months after the injury, elevated stress hormones (i.e. 30 min stimulated cortisol, prolactin and/or IGF1) and/or suppressed gonadal or thyroid hormones were recorded in 68 and 32% of the patients respectively. At 1 year after the injury, lower functioning level (Functional Independence Measure) and lower capability of performing normal life activities (Glasgow Outcome Scale-Extended) were related to both the elevated stress hormones (P≤0.01) and the reduced gonadal and/or thyroid hormones (P≤0.01) measured at 3 months.

CONCLUSION

The present study suggests that brain injury-related endocrine alterations that mimic secondary hypogonadism and hypothyroidism and that occur with elevated stress hormones most probably reflect a prolonged stress response 2-5 months after severe brain injury, rather than pituitary insufficiency per se. These endocrine alterations thus seem to reflect a more severe disease state and relate to 1-year functional outcome.

Clinical outcomes, predictors, and prevalence of anterior pituitary disorders following traumatic brain injury: a systematic review

OBJECTIVES

To assess the clinical outcomes, predictors, and prevalence of anterior pituitary disorders following traumatic brain injury.

DATA SOURCES

We searched Medline, Embase, Cochrane Registry, BIOSIS, and Trip Database up to February 2012 and consulted bibliographies of narrative reviews and selected articles.

STUDY SELECTION

We included cohort, case-control, cross-sectional studies and randomized trials enrolling at least five adults with blunt traumatic brain injury in whom at least one anterior pituitary axis was assessed. We excluded case series and studies in which other neurological conditions were indistinguishable from traumatic brain injury.

DATA EXTRACTION

Two independent reviewers selected citations, extracted data, and assessed the risk of bias using a standardized form.

DATA SYNTHESIS

We performed meta-analyses using random effect models and assessed heterogeneity using the I index.

RESULTS

We included 66 studies (5,386 patients) evaluating prevalence, 14 evaluating clinical outcomes, and 27 evaluating predictors. Thirty studies were at low risk of bias. Anterior pituitary disorders were associated with a trend toward increased ICU mortality (risk ratio, 1.79; 95% CI, 0.99-3.21; four studies) and no difference in Glasgow Outcome Scale score (mean difference, -0.45; 95% CI, -1.10 to 0.20; three studies). Age (mean difference, 3.19; 95% CI, 0.31-6.08; 19 studies), traumatic brain injury severity (risk ratio, 2.15; 95% CI, 1.20-3.86 for patients with severe vs nonsevere traumatic brain injury; seven studies), and skull fractures (risk ratio, 1.73; 95% CI, 1.03-2.91; six studies) predicted anterior pituitary disorders. Over the long term, 31.6% (95% CI, 23.6-40.1%; 27 studies) of patients had at least one anterior pituitary disorder. We observed significant heterogeneity that was not solely explained by the risk of bias or traumatic brain injury severity.

CONCLUSIONS

Approximately one third of traumatic brain injury patients have persistent anterior pituitary disorder. Older age, traumatic brain injury severity, and skull fractures predict anterior pituitary disorders, which in turn may be associated with higher ICU mortality. Further high-quality studies are warranted to better define the burden of anterior pituitary disorders and to identify high-risk patients.

Hypothalamic-pituitary dysfunction following traumatic brain injury affects functional improvement during acute inpatient rehabilitation

OBJECTIVE

To evaluate the occurrence of hypothalamic-pituitary dysfunction following a traumatic brain injury (TBI) and to determine its effect on functional improvement in acute inpatient rehabilitation.

METHODS

A retrospective chart review identified male patients with a primary diagnosis of TBI with or without a skull fracture, an onset date within 6 months prior to admission, and were 16 years of age or older. The percentage of individuals in this population with abnormal hormone levels was determined on the basis of the established normal reference range for each hormone assay. The functional independence measure, which assesses functional outcomes in acute inpatient rehabilitation, was used to examine the relationship between hormone levels and functional improvement.

RESULTS

Hypothalamic-pituitary dysfunction was identified in nearly 70% of men following TBI. Hypogonadism, or low testosterone levels, was observed in 66% of the patients, followed by low levels of free T4 in 46% and low levels of insulin growth factor-1 in 26% of patients. Hypopituitarism associated with impaired functional recovery. Specifically, the functional independence measure change per day was significantly lower in patients with low levels of testosterone and insulin growth factor-1.

CONCLUSIONS

These findings suggest the importance of testosterone and insulin growth factor-1 activity in the early stages of physical and cognitive rehabilitation.

Screening for hypopituitarism in 509 patients with traumatic brain injury or subarachnoid hemorrhage

We performed a screening on patients with traumatic brain injury (TBI) or subarachnoid hemorrhage (SAH) to determine the prevalence of post-traumatic hypopituitarism in neurorehabilitation in a cross-sectional, observational single-center study. In addition, the therapeutic consequences of our screening were analyzed retrospectively. From February 2006 to August 2009, patients between 18 and 65 years (n=509) with the diagnosis of TBI (n=340) or SAH (n=169) were screened within two weeks of admittance to neurorehabilitation as clinical routine. Blood was drawn to determine fasting cortisol, free thyroxine (fT4), prolactin, testosterone or estradiol, and insulin-like growth factor I (IGF-I). Patients with abnormalities in the screening or clinical signs of hypopituitarism received further stimulation tests: growth hormone releasing hormone -L-arginine-test and adrenocorticotrophic hormone (ACTH)-test (n=36); ACTH-test alone (n=26); or insulin tolerance test (n=56). In our screening of 509 patients, 28.5% showed lowered values in at least one hormone of the hypothalamus-pituitary axis and 4.5% in two or more axes. The most common disturbance was a decrease of testosterone in 40.7% of all men (in the following 13/131 men were given substitution therapy). Low fT4 was detected in 5.9% (n=3 were given substitution therapy). Low IGF-I was detected in 5.8%, low cortisol in 1.4%, and low prolactin in 0.2%; none were given substitution therapy. Further stimulation tests revealed growth hormone deficiency in 20.7% (n=19/92) and hypocortisolism in 23.7% (n=28/118). Laboratory values possibly indicating hypopituitarism (33%) were common but did not always implicate post-traumatic hypopituitarism. Laboratory values possibly indicating hypopituitarism were common in our screening but most patients were clinically not diagnosed as pituitary insufficient and did not receive hormone replacement therapy. A routine screening of all patients in neurorehabilitation without considering the time since injury, the severity of illness and therapeutic consequences seems not useful.

The impact of traumatic brain injury on pituitary function

It is paramount that clinicians who care for patients with traumatic brain injury (TBI) at any point in time, including neurosurgeons, rehabilitation physicians, internists, neurologists, and endocrinologists, are aware of the prevalence of posttraumatic hypopituitarism and its impacts on acute and long-term recovery. This article reviews the natural history, pathophysiology, and presenting features of hypopituitarism occurring after TBI. Proposed methodologies for screening, diagnosis, and initiation of treatment are discussed, as well as the effect of hormone replacement therapy on clinical outcomes.

Pituitary dysfunction following traumatic brain injury or subarachnoid haemorrhage - in "Endocrine Management in the Intensive Care Unit"

Traumatic brain injury and subarachnoid haemorrhage are important causes of morbidity and mortality in the developed world. There is a large body of evidence that demonstrates that both conditions may adversely affect pituitary function in both the acute and chronic phases of recovery. Diagnosis of hypopituitarism and accurate treatment of pituitary disorders offers the opportunity to improve mortality and outcome in both traumatic brain injury and subarachnoid haemorrhage. In this article, we will review the history and pathophysiology of pituitary function in the acute phase following traumatic brain injury and subarachnoid haemorrhage, and we will discuss in detail three key aspects of pituitary dysfunction which occur in the early course of TBI; acute cortisol deficiency, diabetes insipidus and SIAD.