Prevalence of hypopituitarism and growth hormone deficiency in adults long-term after severe traumatic brain injury

Increased Adrenocorticotropic Hormone Levels Predict Recovery of Consciousness in Patients With Disorders of Consciousness

The potential influence of pituitary-related hormones (including both pituitary gland and target gland hormones) on functional recovery after traumatic brain injury has been observed. However, the relationship between these hormones and the recovery of consciousness in patients with disorders of consciousness (DOC) remains unclear. In this retrospective and observational study, 208 patients with DOC were recruited. According to the Glasgow Outcome Scale (GOS) scores after 6 months, patients with DOC were categorized into two subgroups: a favorable prognosis subgroup (n = 38) comprising those who regained consciousness (GOS score ≥3), and a poor prognosis subgroup (n = 156) comprising those who remained in DOC (GOS score <3). Comparative analyses of pituitary-related hormone levels between the two subgroups were conducted. Further, a binary logistic regression analysis was conducted to assess the predictive value of pituitary-related hormones for the patients' prognosis. The favorable prognosis subgroup showed a significant increase in adrenocorticotropic hormone (ACTH) levels (p = 0.036). Moreover, higher ACTH levels and shorter days since injury were significantly associated with a better prognosis, with odds ratios (ORs) of 0.928 (95% confidence interval [CI] = 0.873-0.985, p = 0.014) and 1.015 (95% CI = 1.005-1.026, p = 0.005), respectively. A subsequent receiver operating characteristic (ROC) analysis demonstrated the potential to predict patients' prognosis with an area under the curve value of 0.78, an overall accuracy of 75.5%, a sensitivity of 77.5%, and a specificity of 66.7%. Our findings indicate that ACTH levels could serve as a clinically valuable and convenient predictor for patients' prognosis.

Insights into non-classic and emerging causes of hypopituitarism

Hypopituitarism is defined as one or more partial or complete pituitary hormone deficiencies, which are related to the anterior and/or posterior gland and can have an onset in childhood or adulthood. The most common aetiology is a sellar or suprasellar lesion, often an adenoma, which causes hypopituitarism due to tumour mass effects, or the effects of surgery and/or radiation therapy. However, other clinical conditions, such as traumatic brain injury, and autoimmune and inflammatory diseases, can result in hypopituitarism, and there are also genetic causes of hypopituitarism. Furthermore, the use of immune checkpoint inhibitors to treat cancer is increasing the risk of hypopituitarism, with a pattern of hormone defects that is different from the classic patterns and depends on mechanisms that are specific for each drug. Moreover, autoantibody production against the pituitary and hypothalamus has been demonstrated in studies investigating the development or worsening of some cases of hypopituitarism. Finally, evidence suggests that posterior pituitary damage can affect oxytocin secretion. The aim of this Review is to summarize current knowledge on non-classic and emerging causes of hypopituitarism, so as to help clinicians improve early identification, avoid life-threatening events and improve the clinical care and quality of life of patients at risk of hypopituitarism.

Endocrine Dysfunction in Traumatic Subarachnoid Hemorrhage: A Prospective Study

Background This study has prospectively investigated pituitary function and their correlation with severity, pressure effect, and Glasgow outcome scale in the acute phase of traumatic subarachnoid hemorrhage (SAH). Most of the retrospective studies have demonstrated that traumatic SAH-mediated hypopituitarism could be more frequent than previously known.

Objectives The aim of the study is to find the prevalence of endocrine dysfunction in traumatic SAH and its correlation with severity of injury and final outcome.

Materials and Methods Eighty-four consecutive patients of traumatic SAH formed the study group. Apart from clinical assessment, noncontrast computed tomography of the head was performed on all patients on admission. The hormonal analysis (FT3, FT4, thyroid-stimulating hormone, growth hormone [GH], cortisol, prolactin, testosterone) was performed within 24 hours of traumatic brain injury and was repeated on the seventh day amongst the patients who survived.

Results Most common hormone to increase on day one was cortisol (48.78%), while on day seven follicle-stimulating hormones and cortisol (15.38%) showed increment in levels. Most common hormone to decrease on day one was FT3 (36.84%) and GH (36.26%), while on day seven testosterone (66.67%) and FT4 (30.76%) showed decreasing levels. Hormone most resistant to change was prolactin.

Conclusion Hormonal dysfunction is common in moderate to severe traumatic brain injury. There is a direct association between radiological grading (Fischer) of SAH and hormonal profile changes. Performance of hormonal analysis should be considered in patients with moderate to severe traumatic brain injury, preferably with high-grade SAH, so that appropriate hormonal replacement can be done to optimize the clinical outcome.

The brain-gut axis: A prime therapeutic target in traumatic brain injury

Traumatic brain injury (TBI) is a significant cause of morbidity and mortality in trauma patients. The primary focus of treating TBI is to prevent additional injury to the damaged brain tissue, known as secondary brain injury. This treatment can include treating the body's inflammatory response. Despite promise in animal models, anti-inflammatory therapy has failed to improve outcomes in human patients, suggesting a more targeted and precise approach may be needed. There is a bidirectional axis between the intestine and the brain that contributes to this inflammation in acute and chronic injury. The mechanisms for this interaction are not completely understood, but there is evidence that neural, inflammatory, endocrine, and microbiome signals all participate in this process. Therapies that target the intestine as a source of inflammation have potential to lessen secondary brain injury and improve outcomes in TBI patients, but to develop these treatments we need to better understand the mechanisms behind this intestinal inflammatory response.

Surgical Management of Trauma-Related Intracranial Hemorrhage-a Review

PURPOSE OF REVIEW

The surgical management of trauma-related intracranial hemorrhage is characterized by marked heterogeneity. Large prospective randomized trials have generally been prohibited by the ubiquity of concordant pathology, diversity of trauma systems, and paucity of clinical equipoise among providers.

RECENT FINDINGS

To date, the results of retrospective studies and surgeon preference have driven the indications, modality, extent, and timing of surgical intervention in the global neurosurgical community. With advances in our understanding of the pathophysiology of hemorrhagic TBI and the advent of novel surgical techniques, a reevaluation of surgical indication, timing, and approach is warranted. In this way, we can work to optimize surgical outcomes, achieving maximal functional recovery while minimizing surgical morbidity.

Pituitary dysfunction after traumatic brain injury: prevalence and screening strategies

INTRODUCTION

Pituitary gland is vulnerable to traumatic brain injury (TBI). As a result a series of neuroendocrine changes appear after head injury; in many occasions they reverse with time, while occasionally new late onset changes may develop.

AREAS COVERED

In this review, we focus on the prevalence of anterior and posterior pituitary hormonal changes in the acute and chronic post-TBI period in both children and adults. Moreover, we present evidence supporting the need for evaluating pituitary function along with the current suggestions for the most appropriate screening strategies. We attempted to identify all published literature and we conducted an online search of PubMed, from January 1970 to June 2020.

EXPERT OPINION

Adrenal insufficiency and water metabolism disorders are medical emergencies and should be promptly recognized. Awareness for long-term hormonal derangements is necessary, as they may lead to a series of chronic health issues and compromise quality of life. There is a need for well-designed prospective long-term studies that will estimate pituitary function during the acute and chronic phase after head injury.

Prevalence of hypopituitarism and quality of life in survivors of post-traumatic brain injury

BACKGROUND

Hypopituitarism is a recognized sequela of traumatic brain injury (TBI) and may worsen the quality of life (QoL) in survivors.

AIMS

To assess the prevalence of post-traumatic hypopituitarism (PTHP) and growth hormone deficiency (GHD), and determine their correlation with QoL.

METHODS

Survivors of moderate to severe TBI were recruited from two Algerian centres. At 3 and 12 months, pituitary function was evaluated using insulin tolerance test (ITT), QoL by growth hormone deficiency in adults' questionnaire (QoL-AGHDA), and 36-item short-form (SF-36) health survey.

RESULTS

Of 133 (M: 128; F: 5) patients aged 18-65 years, PTHP and GHD were present at 3 and 12 months in 59 (44.4%) and 23 (17.29%), 41/116 (35.3%) and 18 (15.5%). Thirteen patients with GHD at 3 months tested normally at 12 months, while 9 had become GHD at 12 months. At 3 and 12 months, peak cortisol was < 500 nmol/L) in 39 (29.3%) and 29 (25%) patients, but <300 nmol/L in only five and seven. Prevalence for gonadotrophin deficiency was 6.8/8.6%, hypo- and hyperprolactinaemia 6.8/3.8% and 5.2/8.6%, and thyrotrophin deficiency 1.5/0.9%. Mean scores for QoL-AGHDA were higher in patients with PTHP at 3 and 12 months: 7.07 vs 3.62 (P = .001) and in patients with GHD at 12 months: 8.72 vs 4.09 (P = .015). Mean SF-36 scores were significantly lower for PTHP at 3 months.

CONCLUSION

Prevalence of PTHP and GHD changes with time. AGHDA measures QoL in GHD more specifically than SF-36. Full pituitary evaluation and QoL-AGHDA 12 months after TBI are recommended.

Long-term neuroendocrine consequences of traumatic brain injury and strategies for management

Introduction: Traumatic brain injuries (TBI) are reported to cause neuroendocrine impairment with a prevalence of 15% with confirmatory testing. Pituitary dysfunction (PD) may have detrimental effects on vital parameters as well as on body composition, cardiovascular functions, cognition, and quality of life. Therefore, much effort has been made to identify predictive factors for post-TBI PD and various screening strategies have been offered.Areas covered: We searched PubMed and reviewed the recent data on clinical perspectives and long-term outcomes as well as predictive factors and screening modalities of post-TBI PD. Inconsistencies in the literature are overviewed and new areas of research are discussed.Expert opinion: Studies investigating biomarkers that will accurately predict TBI patients with a high risk of PD are generally pilot studies with a small number of participants. Anti-pituitary and anti-hypothalamic antibodies, neural proteins, micro-RNAs are promising in this field. As severity of TBI has been the most commonly associated risk factor for post-TBI PD, we suggest prospective screening based on severity of head trauma until new evidence emerges. There is also a need for more studies investigating the clinical effects of hormone replacement in TBI patients with PD.

Epidemiology of Pediatric Traumatic Brain Injury and Hypothalamic-Pituitary Disorders in Arizona

Traumatic brain injury (TBI) in children can result in long-lasting social, cognitive, and neurological impairments. In adults, TBI can lead to endocrinopathies (endocrine system disorders), but this is infrequently reported in children. Untreated endocrinopathies can elevate risks of subsequent health issues, such that early detection in pediatric TBI survivors can initiate clinical interventions. To understand the risk of endocrinopathies following pediatric TBI, we identified patients who had experienced a TBI and subsequently developed a new-onset hypothalamic regulated endocrinopathy (n = 498). We hypothesized that pediatric patients who were diagnosed with a TBI were at higher risk of being diagnosed with a central endocrinopathy than those without a prior diagnosis of TBI. In our epidemiological assessment, we identified pediatric patients enrolled in the Arizona Health Care Cost Containment System (AHCCCS) from 2008 to 2014 who were diagnosed with one of 330 TBI International Classification of Diseases (ICD)-9 codes and subsequently diagnosed with one of 14 central endocrinopathy ICD-9 codes. Additionally, the ICD-9 code data from over 600,000 Arizona pediatric patients afforded an estimate of the incidence, prevalence, relative risk, odds ratio, and number needed to harm, regarding the development of a central endocrinopathy after sustaining a TBI in Arizona Medicaid pediatric patients. Children with a TBI diagnosis had 3.22 times the risk of a subsequent central endocrine diagnosis compared with the general population (±0.28). Pediatric AHCCCS patients with a central endocrine diagnosis had 3.2-fold higher odds of a history of a TBI diagnosis than those without an endocrine diagnosis (±0.29). Furthermore, the number of patients with a TBI diagnosis for one patient to receive a diagnosis of a central endocrine diagnosis was 151.2 (±6.12). Female subjects were more likely to present with a central endocrine diagnosis after a TBI diagnosis compared to male subjects (64.1 vs. 35.9%). These results are the first state-wide epidemiological study conducted to determine the risk of developing a hypothalamic-pituitary disorder after a TBI in the pediatric population. Our results contribute to a body of knowledge demonstrating a TBI etiology for idiopathic endocrine disorders, and thus advise physicians with regard to TBI follow-up care that includes preventive screening for endocrine disorders.

Prevalence of Anterior Pituitary Dysfunction Twelve Months or More following Traumatic Brain Injury in Adults: A Systematic Review and Meta-Analysis

The objective of this study is to systematically review clinical studies that have reported on the prevalence of chronic post-traumatic brain injury anterior pituitary dysfunction (PTPD) 12 months or more following traumatic brain injury (TBI). We searched Medline, Embase, and PubMed up to April 2017 and consulted bibliographies of narrative reviews. We included cohort, case-control, and cross-sectional studies enrolling at least five adults with primary TBI in whom at least one anterior pituitary axis was assessed at least 12 months following TBI. We excluded studies in which other brain injuries were indistinguishable from TBI. Study quality was assessed using the Newcastle-Ottawa Scale (NOS) score. We also considered studies that determined growth hormone deficiency and adrenocorticotrophic hormone reserve using provocation test to be at low risk of bias. Data were extracted by four independent reviewers and assessed for risk of bias using a data extraction form. We performed meta-analyses using random effect models and assessed heterogeneity using the I² index. We identified 58 publications, of which 29 (2756 participants) were selected for meta-analysis. Twelve of these were deemed to be at low risk of bias and therefore "high-quality," as they had NOS scores greater than 8 and had used provocation tests. The overall prevalence of at least one anterior pituitary hormone dysfunction for all 29 studies was 32% (95% confidence interval [CI] 25-38%). The overall prevalence in the 12 high-quality studies was 34% (95% CI 27-42%). We observed significant heterogeneity that was not solely explained by the risk of bias. Studies with a higher proportion of participants with mild TBI had a lower prevalence of PTPD. Our results show that approximately one-third of TBI sufferers have persistent anterior pituitary dysfunction 12 months or more following trauma. Future research on PTPD should differentiate between mild and moderate/severe TBI.

The frequency and the diagnosis of pituitary dysfunction after traumatic brain injury

PURPOSE

Clinical research studies over the last 15 years have reported a significant burden of hypopituitarism in survivors of traumatic brain injury (TBI). However, debate still exists about the true prevalence of hypopituitarism after head injury.

METHODS

We have reviewed the literature describing the frequency of post-traumatic hypopituitarism and discuss the factors which may explain the variable frequency of the reported deficits in clinical studies including research methodology and the natural history of the disease.

RESULTS

Pituitary hormone perturbations in the acute phase following injury are frequent but are difficult to attribute to traumatic pituitary damage due to physiological hormonal changes in acute illness, the confounding effect of medications, other co-morbidities and lack of appropriate control subjects. Nevertheless, a small number of studies have emphasised the clinical importance of acute, dynamic disturbance of the hypothalamic-pituitary-adrenal axis. There is a much larger evidence base examining the frequency of hypopituitarism in the chronic, recovery phase following head injury. These studies report a very broad prevalence of long-term pituitary hormone dysfunction in survivors of TBI. However, systematic review suggests the prevalence to be between 27 and 31%.

CONCLUSION

Survivors of head injury are at risk of pituitary hormone dysfunction and we suggest an approach to the diagnosis of post-traumatic hypopituitarism in routine clinical practice.

Clinical picture and the treatment of TBI-induced hypopituitarism

Traumatic brain injury (TBI) is an important public health problem with an increasing incidence in the last years. Relatively few cases are fatal; most individuals will survive and, in the long-term, the sequalae of TBI will include neuroendocrine dysfunctions with a much higher frequency than previously suspected. Patients who develop hypopituitarism after TBI present manifestations due to the number of deficient hormones, severity of hormonal deficiency, and the duration of hypopituitarism without diagnosis and treatment. The clinical spectrum of hypopituitarism is very large and many signs and symptoms of TBI survivors such as fatigue, concentration difficulties, depressive symptoms are nonspecific and overlap with symptoms of post-traumatic stress disorder and variably severe hypopituitarism related to brain damage remaining undiagnosed. This can explain why the diagnosis of hypopituitarism is often missed or delayed after this condition with potentially serious and hazardous consequences for the affected patients. Moreover, clinical experience cumulatively suggests that TBI-associated hypopituitarism is associated with poor recovery and worse outcome, since post-traumatic hypopituitarism is independently associated with cognitive impairment, poor quality of life, abnormal body composition, and adverse metabolic profile. In the present review, the current data related to clinical consequences of pituitary dysfunction after TBI in adult patients and therapeutic approaches are reported.

The role of autoimmunity in pituitary dysfunction due to traumatic brain injury

PURPOSE

Traumatic brain injury (TBI) is one of the most common causes of mortality and long-term disability and it is associated with an increased prevalence of neuroendocrine dysfunctions. Post-traumatic hypopituitarism (PTHP) results in major physical, psychological and social consequences leading to impaired quality of life. PTHP can occur at any time after traumatic event, evolving through various ways and degrees of deficit, requiring appropriate screening for early detection and treatment. Although the PTHP pathophysiology remains to be elucitated, on the basis of proposed hypotheses it seems to be the result of combined pathological processes, with a possible role played by hypothalamic-pituitary autoimmunity (HPA). This review is aimed at focusing on this possible role in the development of PTHP and its potential clinical consequences, on the basis of the data so far appeared in the literature and of some results of personal studies on this issue.

METHODS

Scrutinizing the data so far appeared in literature on this topic, we have found only few studies evaluating the autoimmune pattern in affected patients, searching in particular for antipituitary and antihypothalamus autoantibodies (APA and AHA, respectively) by simple indirect immunofluorescence.

RESULTS

The presence of APA and/or AHA at high titers was associated with an increased risk of onset/persistence of PTHP.

CONCLUSIONS

HPA seems to contribute to TBI-induced pituitary damage and related PTHP. However, further prospective studies in a larger cohort of patients are needed to define etiopathogenic and diagnostic role of APA/AHA in development of post-traumatic hypothalamic/pituitary dysfunctions after a TBI.

Pituitary pathology in traumatic brain injury: a review

PURPOSE

Traumatic brain injury most commonly affects young adults under the age of 35 and frequently results in reduced quality of life, disability, and death. In long-term survivors, hypopituitarism is a common complication.

RESULTS

Pituitary dysfunction occurs in approximately 20-40% of patients diagnosed with moderate and severe traumatic brain injury giving rise to growth hormone deficiency, hypogonadism, hypothyroidism, hypocortisolism, and central diabetes insipidus. Varying degrees of hypopituitarism have been identified in patients during both the acute and chronic phase. Anterior pituitary hormone deficiency has been shown to cause morbidity and increase mortality in TBI patients, already encumbered by other complications. Hypopituitarism after childhood traumatic brain injury may cause treatable morbidity in those survivors. Prospective studies indicate that the incidence rate of hypopituitarism may be ten-fold higher than assumed; factors altering reports include case definition, geographic location, variable hospital coding, and lost notes. While the precise pathophysiology of post traumatic hypopituitarism has not yet been elucidated, it has been hypothesized that, apart from the primary mechanical event, secondary insults such as hypotension, hypoxia, increased intracranial pressure, as well as changes in cerebral flow and metabolism may contribute to hypothalamic-pituitary damage. A number of mechanisms have been proposed to clarify the causes of primary mechanical events giving rise to ischemic adenohypophysial infarction and the ensuing development of hypopituitarism.

CONCLUSION

Future research should focus more on experimental and clinical studies to elucidate the exact mechanisms behind post-traumatic pituitary damage. The use of preventive medical measures to limit possible damage in the pituitary gland and hypothalamic pituitary axis in order to maintain or re-establish near normal physiologic functions are crucial to minimize the effects of TBI.

Hypopituitarism After Traumatic Brain Injury

Acquired hypopituitarism is associated with traumatic brain injury. This neuroendocrine dysfunction can cause both short-term and long-term morbidity resulting in a cognitive, physiological, and behavioral decline, which increases the burden of the disease and the cost of care. Data in the trauma literature is derisory on this subject. The aim of this review is to edify clinicians on this condition, outline the screening criteria and methods for hypopituitarism after traumatic brain injury, and bring awareness to the chronic effects.

Patterns of pituitary dysfunction three months or more after traumatic brain injury

PURPOSE

Chronic posttraumatic brain injury (TBI) pituitary dysfunction is not a newly discovered subject, it has been reported more frequently, probably due to increasing chances of exposure to its causes, mainly the road traffic accidents, sport-related injuries, falls, and injuries during wars. This study aims to estimate the frequency of pituitary dysfunction 3 months or more after head trauma and the patterns of hormonal deficiencies.

METHODS

A cross-sectional study was conducted between January 2016 and August 2017. Participants were patients having a history of moderate-to-severe TBI at least 3 months before enrolment. Pituitary function test was done for all patients to determine the frequency of pituitary dysfunction, the number of axes deficiencies, and which hormone is mostly affected. Statistical Package for the Social Sciences (SPSS) version 23.0 was used for univariate analysis, P < 0.05 was considered statistically significant.

RESULTS

Out of the 28 patients involved in this study, 17 (61%) had pituitary dysfunction, while 11 (39%) had not. Single hormonal defect was the most prevalent abnormality in 12 (43%), and the most affected hormone was the growth hormone (GH) in 14 patients (50%), followed by gonadal axis, thyroid stimulating hormone, and finally adrenocorticotropic hormone (ACTH), 6 (21%), 3 (11%), and 1 (4%), respectively.

CONCLUSION

TBI pituitary dysfunction is more prevalent than was predicted in the population studied, single hormonal defect was found to be the most prevalent abnormality, being the GH is the most affected axis, and the ACTH seems to be the least.

Phase 2 Randomized, Placebo-Controlled Clinical Trial of Recombinant Human Growth Hormone (rhGH) During Rehabilitation From Traumatic Brain Injury

Traumatic brain injury (TBI) is a major cause of death and disability, but there are currently no therapies with proven efficacy for optimizing regeneration of repair during rehabilitation. Using standard stimulation tests, as many as 40-50% of survivors of severe TBI have deficiency of one or more pituitary hormones. Of these, the somatotropic axis is the most commonly affected, with Growth Hormone (GH) deficiency affecting ~20% of persons with severe TBI. Treatment with recombinant human Growth Hormone (rhGH) is generally effective in reversing the effects of acquired GH deficiency, but there is no evidence documenting functional or neurocognitive improvement after GH replacement in TBI patients. As a consequence, screening for GH deficiency and GH replacement when deficiency is found is not routinely performed as part of the rehabilitation of TBI survivors. Given that most of the recovery after TBI occurs within the first 6-12 months after injury and IGF-1 and GH are part of a coordinated restorative neurotrophic system, we hypothesized that patients will optimally benefit from GH therapy during the window of maximal neuroregenerative activity. We performed a Phase IIa, randomized, double-blind, placebo-controlled feasibility trial of recombinant human Growth Hormone (rhGH), starting at discharge from an inpatient rehabilitation unit, with follow up at 6 and 12 months. Our primary hypothesis was that treatment with rhGH in the subacute period would result in improved functional outcomes 6 months after injury. Our secondary hypothesis proposed that treatment with rhGH would increase IGF-1 levels and be well tolerated. Sixty-three subjects were randomized, and 40 completed the trial. At baseline, there was no correlation between IGF-1 levels and peak GH levels after L-arginine stimulation. IGF-1 levels increased after rhGH treatment, but it took longer than 1 month for levels to be higher than for placebo-treated patients. rhGH therapy was well-tolerated. The rhGH group was no different from placebo in the Disability Rating Scale, Glasgow Outcome Scale-Extended, or neuropsychological function. However, a trend toward greater improvement from baseline in Functional Independence Measure (FIM) was noted in the rhGH treated group. Future studies should include longer treatment periods, faster titration of rhGH, and larger sample sizes.

Neuroendocrine Abnormalities Following Traumatic Brain Injury: An Important Contributor to Neuropsychiatric Sequelae

Neuropsychiatric symptoms following traumatic brain injury (TBI) are common and contribute negatively to TBI outcomes by reducing overall quality of life. The development of neurobehavioral sequelae, such as concentration deficits, depression, anxiety, fatigue, and loss of emotional well-being has historically been attributed to an ambiguous "post-concussive syndrome," considered secondary to frank structural injury and axonal damage. However, recent research suggests that neuroendocrine dysfunction, specifically hypopituitarism, plays an important role in the etiology of these symptoms. This post-head trauma hypopituitarism (PHTH) has been shown in the past two decades to be a clinically prevalent phenomenon, and given the parallels between neuropsychiatric symptoms associated with non-TBI-induced hypopituitarism and those following TBI, it is now acknowledged that PHTH is likely a substantial contributor to these impairments. The current paper seeks to provide an overview of hypothesized pathophysiological mechanisms underlying neuroendocrine abnormalities after TBI, and to emphasize the significance of this phenomenon in the development of the neurobehavioral problems frequently seen after head trauma.

Long-term Consequences of Traumatic Brain Injury in Bone Metabolism

Traumatic brain injury (TBI) leads to long-term cognitive, behavioral, affective deficits, and increase neurodegenerative diseases. It is only in recent years that there is growing awareness that TBI even in its milder form poses long-term health consequences to not only the brain but to other organ systems. Also, the concept that hormonal signals and neural circuits that originate in the hypothalamus play key roles in regulating skeletal system is gaining recognition based on recent mouse genetic studies. Accordingly, many TBI patients have also presented with hormonal dysfunction, increased skeletal fragility, and increased risk of skeletal diseases. Research from animal models suggests that TBI may exacerbate the activation and inactivation of molecular pathways leading to changes in both osteogenesis and bone destruction. TBI has also been found to induce the formation of heterotopic ossification and increased callus formation at sites of muscle or fracture injury through increased vascularization and activation of systemic factors. Recent studies also suggest that the disruption of endocrine factors and neuropeptides caused by TBI may induce adverse skeletal effects. This review will discuss the long-term consequences of TBI on the skeletal system and TBI-induced signaling pathways that contribute to the formation of ectopic bone, altered fracture healing, and reduced bone mass.

Chronic Hypopituitarism Associated with Increased Postconcussive Symptoms Is Prevalent after Blast-Induced Mild Traumatic Brain Injury

The most frequent injury sustained by US service members deployed to Iraq or Afghanistan is mild traumatic brain injuries (mTBI), or concussion, by far most often caused by blast waves from improvised explosive devices or other explosive ordnance. TBI from all causes gives rise to chronic neuroendocrine disorders with an estimated prevalence of 25-50%. The current study expands upon our earlier finding that chronic pituitary gland dysfunction occurs with a similarly high frequency after blast-related concussions. We measured circulating hormone levels and accessed demographic and testing data from two groups of male veterans with hazardous duty experience in Iraq or Afghanistan. Veterans in the mTBI group had experienced one or more blast-related concussion. Members of the deployment control (DC) group encountered similar deployment conditions but had no history of blast-related mTBI. 12 of 39 (31%) of the mTBI participants and 3 of 20 (15%) veterans in the DC group screened positive for one or more neuroendocrine disorders. Positive screens for growth hormone deficiency occurred most often. Analysis of responses on self-report questionnaires revealed main effects of both mTBI and hypopituitarism on postconcussive and posttraumatic stress disorder (PTSD) symptoms. Symptoms associated with pituitary dysfunction overlap considerably with those of PTSD. They include cognitive deficiencies, mood and anxiety disorders, sleep problems, diminished quality of life, deleterious changes in metabolism and body composition, and increased cardiovascular mortality. When such symptoms are due to hypopituitarism, they may be alleviated by hormone replacement. These findings suggest consideration of routine post-deployment neuroendocrine screening of service members and veterans who have experienced blast-related mTBI and are reporting postconcussive symptoms.

Chronic endocrine consequences of traumatic brain injury - what is the evidence?

Traumatic brain injury (TBI) is a major public health problem with potentially debilitating consequences for the individual. Hypopituitarism after TBI has received increasing attention over the past decade; development of the condition as a consequence of TBI was previously hardly mentioned in textbooks on the subject. Hypopituitarism has been reported in more than 25% of patients with TBI and is now thought to be one of the most important causes of treatable morbidity in TBI survivors. However, most clinicians dealing with neuroendocrine diseases and TBI generally do not see such a high incidence of hypopituitarism. This disproportion is not clearly explained, but recent data indicate that diagnostic testing, which is designed for high-risk populations and not for a cohort of patients with, for example, de novo isolated growth hormone deficiency (the predominant finding in TBI), might have overestimated the true risk and disease burden of hypopituitarism. In this Opinion article, we discuss current recommendations for post-traumatic hypopituitarism in light of recent evidence.

The screening and management of pituitary dysfunction following traumatic brain injury in adults: British Neurotrauma Group guidance

Pituitary dysfunction is a recognised, but potentially underdiagnosed complication of traumatic brain injury (TBI). Post-traumatic hypopituitarism (PTHP) can have major consequences for patients physically, psychologically, emotionally and socially, leading to reduced quality of life, depression and poor rehabilitation outcome. However, studies on the incidence of PTHP have yielded highly variable findings. The risk factors and pathophysiology of this condition are also not yet fully understood. There is currently no national consensus for the screening and detection of PTHP in patients with TBI, with practice likely varying significantly between centres. In view of this, a guidance development group consisting of expert clinicians involved in the care of patients with TBI, including neurosurgeons, neurologists, neurointensivists and endocrinologists, was convened to formulate national guidance with the aim of facilitating consistency and uniformity in the care of patients with TBI, and ensuring timely detection or exclusion of PTHP where appropriate. This article summarises the current literature on PTHP, and sets out guidance for the screening and management of pituitary dysfunction in adult patients with TBI. It is hoped that future research will lead to more definitive recommendations in the form of guidelines.

Pituitary dysfunction after traumatic brain injury: are there definitive data in children?

In the past decade, several studies in adults and children have described the risk of pituitary dysfunction after traumatic brain injury (TBI). As a result, an international consensus statement recommended follow-up on the survivors. This paper reviews published studies regarding hypopituitarism after TBI in children and compares their results. The prevalence of hypopituitarism ranges from 5% to 57%. Growth hormone (GH) and ACTH deficiency are the most common, followed by gonadotropins and thyroid-stimulating hormone. Paediatric studies have failed to identify risk factors for developing hypopituitarism, and therefore we have no tools to restrict screening in severe TBI. In addition, the present review highlights the lack of a unified follow-up and the fact that unrecognised pituitary dysfunction is frequent in paediatric population. The effect of hormonal replacement in patient recovery is important enough to consider baseline screening and reassessment between 6 and 12 months after TBI. Medical community should be aware of the risk of pituitary dysfunction in these patients, given the high prevalence of endocrine dysfunction already reported in the studies. Longer prospective studies are needed to uncover the natural course of pituitary dysfunction, and new studies should be designed to test the benefit of hormonal replacement in metabolic, cognitive and functional outcome in these patients.

An evaluation of neuroendocrine dysfunction following acute aneurysmal subarachnoid hemorrhage: A prospective study

OBJECTIVE

The aim was to investigate the incidence and pattern of neuroendocrine changes in cases of acute aneurysmal subarachnoid hemorrhage (SAH).

MATERIALS AND METHODS

Endocrine assessment was performed in 100 consecutive cases of acute aneurysmal SAH presenting within 7 days of ictus. The gonadotropic, somatotrophic, thyrotropic, and corticotrophic axes were evaluated for their possible dysfunction.

RESULTS

A total of 100 cases (38 males, 62 females; age range - 17-76 years; mean age - 43.6 years) of acute SAH were studied. The aneurysms were located in the anterior circulation (n = 95) and posterior circulation (n = 5). The most common hormone deficiency was of growth hormone (n = 67), followed by gonadotrophin (n = 50), corticotrophin (n = 49) and thyrotrophin (n = 35). Hyperprolactinemia was noted in 10 cases. One-pituitary hormone axis deficiency was noted in 26 cases while 67 cases had two or more pituitary hormone axes dysfunction. A total of 93 cases had hormonal dysfunction in one or more pituitary hormone axes, and seven cases had no hormonal dysfunction.

CONCLUSIONS

Endocrine dysfunction occurs in 93% cases of acute SAH and multiple pituitary hormone axes dysfunction occurs in 67% cases. It is suggested that hormonal evaluation should be considered as part of management of acute SAH.

Prevalence of hypothalamo pituitary dysfunction in patients of traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) is common in young soldiers of armed forces leading to significant morbidity and mortality. We studied the prevalence of hypopituitarism following TBI and its association with trauma severity.

MATERIALS AND METHODS

We conducted a 12-month prospective study of 56 TBI patients for the presence of hormonal dysfunction. Hormonal parameters were estimated during the early phase (0-10 days posttraumatically) and after 6 and 12 months. Dynamic testing was done when required, and the results were analyzed by appropriate statistical methods.

RESULTS

Hormonal dysfunction was seen in 39 of the 56 (70%) patients at initial assessment. Persisting pituitary deficiencies are seen in 7 and 8 patients at the end of 6 months and 12 months, respectively. Hypogonadotropic hypogonadism, hypothyroidism, and growth hormone deficiency are the most common diagnoses. Initial severe TBI and plurihormonal involvement predicted the long-term hypopituitarism.

CONCLUSION

Early hypopituitarism was common in severe TBI, but recovers in majority. Evaluation for the occult pituitary dysfunction is required during the rehabilitation of TBI patients.

Endocrine dysfunction following traumatic brain injury: a 5-year follow-up nationwide-based study

Post-traumatic endocrine dysfunction is a complication of traumatic brain injury (TBI). However, there is lack of long-term follow-up and large sample size studies. This study included patients suffering from TBI registered in the Health Insurance Database. Endocrine disorders were identified using the ICD codes: 244 (acquired hypothyroidism), 253 (pituitary dysfunction), 255 (disorders of the adrenal glands), 258 (polyglandular dysfunction), and 259 (other endocrine disorders) with at least three outpatient visits within 1 year or one admission diagnosis. Overall, 156,945 insured subjects were included in the final analysis. The 1- and 5-year incidence rates of post-traumatic endocrinopathies were 0.4% and 2%, respectively. The risks of developing a common endocrinopathy (p < 0.001) or pituitary dysfunction (P < 0.001) were significantly higher in patients with a TBI history. Patients with a skull bone fracture had a higher risk of developing pituitary dysfunction at the 1-year follow up (p value < 0.001). At the 5-year follow up, the association between intracranial hemorrhage and pituitary dysfunction (p value: 0.002) was significant. The risk of developing endocrine dysfunction after TBI increased during the entire 5-year follow-up period. Skull bone fracture and intracranial hemorrhage may be associated with short and long-term post-traumatic pituitary dysfunction, respectively.

Post-traumatic hypopituitarism: report of a child case

Case

We report a case of post‐traumatic hypopituitarism in a 9‐year‐old boy who was injured in a car accident.

Outcome

Post‐traumatic hypopituitarism might be caused by moderate to severe head trauma, and while this possibility has recently drawn attention in adults, few reports are available regarding children. Our patient experienced head and facial injury, resulting in post‐traumatic hypopituitarism. Six hours after injury he suffered from diabetes insipidus and hormone replacement therapy was started. On day 12 he underwent facial fracture reduction under general anesthesia. On day 24 he was discharged from the hospital. One year after the injury, secretory function and water dehydration tests suggested the possibility of post‐traumatic hypopituitarism.

Conclusion

We experienced a child case of post‐traumatic hypopituitarism. Emergency physicians should pay attention to the possibility of post‐traumatic hypopituitarism in cases of traumatic brain injury.

Neuroendocrine Disturbances One to Five or More Years after Traumatic Brain Injury and Aneurysmal Subarachnoid Hemorrhage: Data from the German Database on Hypopituitarism

Neuroendocrine disturbances are common after traumatic brain injury (TBI) and aneurysmal subarachnoid hemorrhage (SAH), but only a few data exist on long-term anterior pituitary deficiencies after brain injury. We present data from the Structured Data Assessment of Hypopituitarism after TBI and SAH, a multi-center study including 1242 patients. We studied a subgroup of 351 patients, who had sustained a TBI (245) or SAH (106) at least 1 year before endocrine assessment (range 1-55 years) in a separate analysis. The highest prevalence of neuroendocrine disorders was observed 1-2 years post-injury, and it decreased over time only to show another maximum in the long-term phase in patients with brain injury occurring ≥5 years prior to assessment. Gonadotropic and somatotropic insufficiencies were most common. In the subgroup from 1 to 2 years after brain injury (n = 126), gonadotropic insufficiency was the most common hormonal disturbance (19%, 12/63 men) followed by somatotropic insufficiency (11.5%, 7/61), corticotropic insufficiency (9.2%, 11/119), and thyrotropic insufficiency (3.3%, 4/122). In patients observed ≥ 5 years after brain injury, the prevalence of somatotropic insufficiency increased over time to 24.1%, whereas corticotropic and thyrotrophic insufficiency became less frequent (2.5% and 0%, respectively). The prevalence differed regarding the diagnostic criteria (laboratory values vs. physician`s diagnosis vs. stimulation tests). Our data showed that neuroendocrine disturbances are frequent even years after TBI or SAH, in a cohort of patients who are still on medical treatment.

Symptoms of gonadal dysfunction are more predictive of hypopituitarism than nonspecific symptoms in screening for pituitary dysfunction following moderate or severe traumatic brain injury

OBJECTIVE

The economic and logistic burden of screening for hypopituitarism following moderate/severe traumatic brain injury (TBI) is considerable. A key recommendation in published guidelines is to prioritize for screening those patients with symptoms suggestive of pituitary dysfunction. The purpose of this study was to evaluate the utility of targeted screening for hypopituitarism in long-term survivors after moderate/severe TBI using referrals on the basis of symptoms.

DESIGN

In group 1 (G1), consecutive, unselected patients were screened from the Irish National Neurosurgery Centre, whereas in group 2 (G2) patients were targeted based on the presence of symptoms suggestive of pituitary dysfunction.

PATIENTS

A total of 137 patients (113 male) were systematically screened (G1) and compared to 112 patients (77 male) referred for pituitary evaluation on the basis of suggestive symptoms (G2).

MAIN OUTCOME MEASURES

The rate of GH, ACTH, gonadotrophin (GT), TSH and ADH deficiency was compared among groups.

RESULTS

Patients referred with menstrual dysfunction had more GH (50% vs 11%, P = 0·001), ACTH (60% vs 14%, P < 0·0001), GT (90% vs 16%, P < 0·0001) deficiency and any pituitary hormone deficit (80% vs 33%, P = 0·003) than G1. Men with symptoms of hypogonadism had more GH (33% vs 11%, P = 0·003), GT (58% vs 16%, P < 0·0001) and TSH (16% vs 1%, P = 0·03) deficiency than G1. Patients with nonspecific symptoms were no more likely to have hypopituitarism than those consecutively screened.

CONCLUSIONS

Symptoms of hypogonadism are sufficiently predictive of hypopituitarism to justify screening for hypopituitarism after moderate/severe TBI. Nonspecific symptoms of hypopituitarism are no more predictive than unselected screening.

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.

GH and Pituitary Hormone Alterations After Traumatic Brain Injury

Traumatic brain injury (TBI) is a crucially important public health problem around the world, which gives rise to increased mortality and is the leading cause of physical and psychological disability in young adults, in particular. Pituitary dysfunction due to TBI was first described 95 years ago. However, until recently, only a few papers have been published in the literature and for this reason, TBI-induced hypopituitarism has been neglected for a long time. Recent studies have revealed that TBI is one of the leading causes of hypopituitarism. TBI which causes hypopituitarism may be characterized by a single head injury such as from a traffic accident or by chronic repetitive head trauma as seen in combative sports including boxing, kickboxing, and football. Vascular damage, hypoxic insult, direct trauma, genetic predisposition, autoimmunity, and neuroinflammatory changes may have a role in the development of hypopituitarism after TBI. Because of the exceptional structure of the hypothalamo-pituitary vasculature and the special anatomic location of anterior pituitary cells, GH is the most commonly lost hormone after TBI, and the frequency of isolated GHD is considerably high. TBI-induced pituitary dysfunction remains undiagnosed and therefore untreated in most patients because of the nonspecific and subtle clinical manifestations of hypopituitarism. Treatment of TBI-induced hypopituitarism depends on the deficient anterior pituitary hormones. GH replacement therapy has some beneficial effects on metabolic parameters and neurocognitive dysfunction. Patients with TBI without neuroendocrine changes and those with TBI-induced hypopituitarism share the same clinical manifestations, such as attention deficits, impulsion impairment, depression, sleep abnormalities, and cognitive disorders. For this reason, TBI-induced hypopituitarism may be neglected in TBI victims and it would be expected that underlying hypopituitarism would aggravate the clinical picture of TBI itself. Therefore, the diagnosis and treatment of unrecognized hypopituitarism due to TBI are very important not only to decrease morbidity and mortality due to hypopituitarism but also to alleviate the chronic sequelae caused by TBI.

Pituitary and/or hypothalamic dysfunction following moderate to severe traumatic brain injury: Current perspectives

There is an increasing deliberation regarding hypopituitarism following traumatic brain injury (TBI) and recent data have suggested that pituitary dysfunction is very common among survivors of patients having moderate-severe TBI which may evolve or resolve over time. Due to high prevalence of pituitary dysfunction after moderate-severe TBI and its association with increased morbidity and poor recovery and the fact that it can be easily treated with hormone replacement, it has been suggested that early detection and treatment is necessary to prevent long-term neurological consequences. The cause of pituitary dysfunction after TBI is still not well understood, but evidence suggests few possible primary and secondary causes. Results of recent studies focusing on the incidence of hypopituitarism in the acute and chronic phases after TBI are varied in terms of severity and time of occurrence. Although the literature available does not show consistent values and there is difference in study parameters and diagnostic tests used, it is clear that pituitary dysfunction is very common after moderate to severe TBI and patients should be carefully monitored. The exact timing of development cannot be predicted but has suggested regular assessment of pituitary function up to 1 year after TBI. In this narrative review, we aim to explore the current evidence available regarding the incidence of pituitary dysfunction in acute and chronic phase post-TBI and recommendations for screening and follow-up in these patients. We will also focus light over areas in this field worthy of further investigation.

Differences according to Sex in Sociosexuality and Infidelity after Traumatic Brain Injury

OBJECTIVE

To explore differences according to sex in sociosexuality and infidelity in individuals with TBI and in healthy controls.

PARTICIPANTS

Forty-two individuals with mild, moderate, and severe TBI having completed a postacute TBI rehabilitation program, at least six months after injury, and 47 healthy controls.

MAIN MEASURES

Sociosexual Orientation Inventory-Revised (SOI-R) and Attitudes toward Infidelity Scale.

RESULTS

Overall, men score significantly higher than women in sociosexuality. However, there was a nonsignificant trend towards a reduction of sociosexuality levels in men with TBI. Infidelity levels were comparable in healthy controls and individuals with TBI. In individuals with TBI, less acceptance of infidelity was significantly associated with an unrestricted sociosexual orientation, but not in healthy controls.

CONCLUSIONS

As documented in previous cross-cultural studies, men have higher levels of sociosexuality than women. However, men with TBI showed a tendency towards the reduction of sociosexuality. The possibility of a latent explanatory variable is suggested (e.g., post-TBI neuroendocrinological changes). TBI does not seem to have an impact on infidelity, but individuals with TBI who express less acceptance of infidelity also report a more promiscuous mating strategy regarding their behavior, attitudes, and desire. Theoretical implications are discussed in terms of evolutionary theories of human sexuality and neuropsychology.

Hypopituitarism in Traumatic Brain Injury-A Critical Note

While hypopituitarism after traumatic brain injury (TBI) was previously considered rare, it is now thought to be a major cause of treatable morbidity among TBI survivors. Consequently, recommendations for assessment of pituitary function and replacement in TBI were recently introduced. Given the high incidence of TBI with more than 100 pr. 100,000 inhabitants, TBI would be by far the most common cause of hypopituitarism if the recently reported prevalence rates hold true. The disproportion between this proposed incidence and the occasional cases of post-TBI hypopituitarism in clinical practice justifies reflection as to whether hypopituitarism has been unrecognized in TBI patients or whether diagnostic testing designed for high risk populations such as patients with obvious pituitary pathology has overestimated the true risk and thereby the disease burden of hypopituitarism in TBI. The findings on mainly isolated deficiencies in TBI patients, and particularly isolated growth hormone (GH) deficiency, raise the question of the potential impact of methodological confounding, determined by variable test-retest reproducibility, appropriateness of cut-off values, importance of BMI stratified cut-offs, assay heterogeneity, pre-test probability of hypopituitarism and lack of proper individual laboratory controls as reference population. In this review, current recommendations are discussed in light of recent available evidence.

Impaired Pituitary Axes Following Traumatic Brain Injury

Pituitary dysfunction following traumatic brain injury (TBI) is significant and rarely considered by clinicians. This topic has received much more attention in the last decade. The incidence of post TBI anterior pituitary dysfunction is around 30% acutely, and declines to around 20% by one year. Growth hormone and gonadotrophic hormones are the most common deficiencies seen after traumatic brain injury, but also the most likely to spontaneously recover. The majority of deficiencies present within the first year, but extreme delayed presentation has been reported. Information on posterior pituitary dysfunction is less reliable ranging from 3%-40% incidence but prospective data suggests a rate around 5%. The mechanism, risk factors, natural history, and long-term effect of treatment are poorly defined in the literature and limited by a lack of standardization. Post TBI pituitary dysfunction is an entity to recognize with significant clinical relevance. Secondary hypoadrenalism, hypothyroidism and central diabetes insipidus should be treated acutely while deficiencies in growth and gonadotrophic hormones should be initially observed.

Diabetes Insipidus after Traumatic Brain Injury

Traumatic brain injury (TBI) is a significant cause of morbidity and mortality in many age groups. Neuroendocrine dysfunction has been recognized as a consequence of TBI and consists of both anterior and posterior pituitary insufficiency; water and electrolyte abnormalities (diabetes insipidus (DI) and the syndrome of inappropriate antidiuretic hormone secretion (SIADH)) are amongst the most challenging sequelae. The acute head trauma can lead (directly or indirectly) to dysfunction of the hypothalamic neurons secreting antidiuretic hormone (ADH) or of the posterior pituitary gland causing post-traumatic DI (PTDI). PTDI is usually diagnosed in the first days after the trauma presenting with hypotonic polyuria. Frequently, the poor general status of most patients prevents adequate fluid intake to compensate the losses and severe dehydration and hypernatremia occur. Management consists of careful monitoring of fluid balance and hormonal replacement. PTDI is associated with high mortality, particularly when presenting very early following the injury. In many surviving patients, the PTDI is transient, lasting a few days to a few weeks and in a minority of cases, it is permanent requiring management similar to that offered to patients with non-traumatic central DI.

Pituitary dysfunction after traumatic brain injury: a clinical and pathophysiological approach

Traumatic brain injury (TBI) is a growing public health problem worldwide and is a leading cause of death and disability. The causes of TBI include motor vehicle accidents, which are the most common cause, falls, acts of violence, sports-related head traumas, and war accidents including blast-related brain injuries. Recently, pituitary dysfunction has also been described in boxers and kickboxers. Neuroendocrine dysfunction due to TBI was described for the first time in 1918. Only case reports and small case series were reported until 2000, but since then pituitary function in TBI victims has been investigated in more detail. The frequency of hypopituitarism after TBI varies widely among different studies (15-50% of the patients with TBI in most studies). The estimates of persistent hypopituitarism decrease to 12% if repeated testing is applied. GH is the most common hormone lost after TBI, followed by ACTH, gonadotropins (FSH and LH), and TSH. The underlying mechanisms responsible for pituitary dysfunction after TBI are not entirely clear; however, recent studies have shown that genetic predisposition and autoimmunity may have a role. Hypopituitarism after TBI may have a negative impact on the pace or degree of functional recovery and cognition. What is not clear is whether treatment of hypopituitarism has a beneficial effect on specific function. In this review, the current data related to anterior pituitary dysfunction after TBI in adult patients are updated, and guidelines for the diagnosis, follow-up strategies, and therapeutic approaches are reported.

Neuroendocrine Disturbances after Brain Damage: An Important and Often Undiagnosed Disorder

Traumatic brain injury (TBI) is a common and significant public health problem all over the world. Until recently, TBI has been recognized as an uncommon cause of hypopituitarism. The studies conducted during the last 15 years revealed that TBI is a serious cause of hypopituitarism. Although the underlying pathophysiology has not yet been fully clarified, new data indicate that genetic predisposition, autoimmunity and neuroinflammatory changes may play a role in the development of hypopituitarism. Combative sports, including boxing and kickboxing, both of which are characterized by chronic repetitive head trauma, have been shown as new causes of neuroendocrine abnormalities, mainly hypopituitarism, for the first time during the last 10 years. Most patients with TBI-induced pituitary dysfunction remain undiagnosed and untreated because of the non-specific and subtle clinical manifestations of hypopituitarism. Replacement of the deficient hormones, of which GH is the commonest hormone lost, may not only reverse the clinical manifestations and neurocognitive dysfunction, but may also help posttraumatic disabled patients resistant to classical treatment who have undiagnosed hypopituitarism and GH deficiency in particular. Therefore, early diagnosis, which depends on the awareness of TBI as a cause of neuroendocrine abnormalities among the medical community, is crucially important.

GH deficiency after traumatic brain injury: improvement in quality of life with GH therapy: analysis of the KIMS database

OBJECTIVE

Prevalence of GH deficiency (GHD) caused by traumatic brain injury (TBI) is highly variable. Short-term studies show improvement in quality of life (QoL) during GH replacement (GHR), but long-term data are lacking. The aim of this study was to analyse the clinical characteristics of post-traumatic hypopituitarism and the QoL effects of long-term GHR.

DESIGN/METHODS

Pfizer International Metabolic Database patients with GHD caused by TBI and by non-functioning pituitary adenoma (NFPA) were compared regarding: clinical characteristics at baseline and 1-year of GHR, and QoL response up to 8-years of GHR (QoL-AGHDA total scores and dimensions) in relationship with country-specific norms.

RESULTS

TBI patients compared with NFPA patients were younger, diagnosed with GHD 2.4 years later after primary disease onset (P<0.0001), had a higher incidence of isolated GHD, higher GH peak, a more favourable metabolic profile and worse QoL, were shorter by 0.9 cm (1.8 cm when corrected for age and gender; P=0.004) and received higher GH dose (mean difference: 0.04 mg/day P=0.006). In TBI patients, 1-year improvement in QoL was greater than in NFPA (change in QoL-AGHDA score 5.0 vs 3.5, respectively, P=0.04) and was sustained over 8 years. In TBI patients, socialisation normalised after 1 year of GHR, self-confidence and tenseness after 6 years and no normalisation of tiredness and memory was observed.

CONCLUSION

Compared with NFPA, TBI patients presented biochemically with less severe hypopituitarism and worse QoL scores. GHR achieved clinically relevant, long-term benefit in QoL.

Hypopituitarism after traumatic brain injury

The prevalence of hypopituitarism after traumatic brain (TBI) injury is widely variable in the literature; a meta-analysis determined a pooled prevalence of anterior hypopituitarism of 27.5%. Growth hormone deficiency is the most prevalent hormone insufficiency after TBI; however, the prevalence of each type of pituitary deficiency is influenced by the assays used for diagnosis, severity of head trauma, and time of evaluation. Recent studies have demonstrated improvement in cognitive function and cognitive quality of life with substitution therapy in GH-deficient patients after TBI.

Pituitary dysfunction following traumatic brain injury: clinical perspectives

Traumatic brain injury (TBI) is a well recognized public health problem worldwide. TBI has previously been considered as a rare cause of hypopituitarism, but an increased prevalence of neuroendocrine dysfunction in patients with TBI has been reported during the last 15 years in most of the retrospective and prospective studies. Based on data in the current literature, approximately 15%-20% of TBI patients develop chronic hypopituitarism, which clearly suggests that TBI-induced hypopituitarism is frequent in contrast with previous assumptions. This review summarizes the current data on TBI-induced hypopituitarism and briefly discusses some clinical perspectives on post-traumatic anterior pituitary hormone deficiency.

Prevalence of pituitary hormone dysfunction, metabolic syndrome, and impaired quality of life in retired professional football players: a prospective study

Hypopituitarism is common after moderate and severe traumatic brain injury (TBI). Herein, we address the association between mild TBI (mTBI) and pituitary and metabolic function in retired football players. Retirees 30-65 years of age, with one or more years of National Football League (NFL) play and poor quality of life (QoL) based on Short Form 36 (SF-36) Mental Component Score (MCS) were prospectively enrolled. Pituitary hormonal and metabolic syndrome (MetS) testing was performed. Using a glucagon stimulation test, growth hormone deficiency (GHD) was defined with a standard cut point of 3 ng/mL and with a more stringent body mass index (BMI)-adjusted cut point. Subjects with and without hormonal deficiency (HD) were compared in terms of QoL, International Index of Erectile Function (IIEF) scores, metabolic parameters, and football career data. Of 74 subjects, 6 were excluded because of significant non-football-related TBIs. Of the remaining 68 subjects (mean age, 47.3±10.2 years; median NFL years, 5; median NFL concussions, 3; mean BMI, 33.8±6.0), 28 (41.2%) were GHD using a peak GH cutoff of <3 ng/mL. However, with a BMI-adjusted definition of GHD, 13 of 68 (19.1%) were GHD. Using this BMI-adjusted definition, overall HD was found in 16 (23.5%) subjects: 10 (14.7%) with isolated GHD; 3 (4.4%) with isolated hypogonadism; and 3 (4.4%) with both GHD and hypogonadism. Subjects with HD had lower mean scores on the IIEF survey (p=0.016) and trended toward lower scores on the SF-36 MCS (p=0.113). MetS was present in 50% of subjects, including 5 of 6 (83%) with hypogonadism, and 29 of 62 (46.8%) without hypogonadism (p=0.087). Age, BMI, median years in NFL, games played, number of concussions, and acknowledged use of performance-enhancing steroids were similar between HD and non-HD groups. In summary, in this cohort of retired NFL players with poor QoL, 23.5% had HD, including 19% with GHD (using a BMI-adjusted definition), 9% with hypogonadism, and 50% had MetS. Although the cause of HD is unclear, these results suggest that GHD and hypogonadism may contribute to poor QoL, erectile dysfunction, and MetS in this population. Further study of pituitary function is warranted in athletes sustaining repetitive mTBI.

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.