Prevalence of anterior pituitary dysfunction in patients following traumatic brain injury in a German multi-centre screening program

Traumatic brain injury and prolactin

Traumatic brain injury (TBI) is a well-known etiologic factor for pituitary dysfunctions, with a prevalence of 15% during long-term follow-up. The most common hormonal disruption is growth hormone deficiency, followed by central adrenal insufficiency, central hypogonadism, and central hypothyroidism in varying order across studies. The prevalence of serum prolactin disturbances ranged widely from 0 to 85%. Prolactin release is mainly regulated by hypothalamic dopamine inhibition, and mediators such as TRH, serotonin, cytokines, and neurotransmitters have modulatory effects. Many factors, such as hypothalamic and/or pituitary gland injuries, as well as fluctuations in dopaminergic activity and other mediators and stress response, may cause derangements in serum prolactin levels after TBI. Although it is challenging to investigate the direct effects of TBI on serum prolactin levels due to many confounders, basal prolactin measurements and stimulation tests provide insight into the functionality of the hypothalamus and pituitary gland after TBI. Moreover, during the acute phase of TBI, prolactin levels appear to correlate with TBI severity. In contrast, in the chronic phase, hypoprolactinemia may function as an indirect indicator of pituitary dysfunction and reduced pituitary volume. Further investigations are needed to elucidate the pathophysiologic mechanisms underlying the prolactin trend following TBI, its significance, and its associations with other pituitary hormone dysfunctions. In this article, we re-evaluated our patients' TBI data regarding prolactin levels during prospective long-term follow-up, and reviewed the literature regarding the prevalence, pathophysiology, and clinical implications of serum prolactin disturbances during acute and chronic phases following TBI.

Optimal vitamin D level ameliorates neurological outcome and quality of life after traumatic brain injury: a clinical perspective

BACKGROUND

Deficiency of vitamin D along with traumatic brain injury (TBI) augments the risk of injury severity. This possibly affects the therapeutic regimen prescribed for TBI which may pessimistically affects its outcome.

METHODS

Studies literature search was conducted in Google Scholar and PubMed. The inclusions were studies performed clinically on both male and female. All included studies' references were also reviewed to find any additional relevance related to this review. Studies published in English were considered for this review. This review focuses upon the incidence of vitamin D deficiency in TBI and how it affects the Quality of life of the sufferer.

RESULTS

A total of 176 studies were reviewed and 58 were thoroughly focussed for review as they met inclusion criteria. These studies demonstrate that levels of vitamin D influence the recovery outcome after TBI. Vitamin D deficiency has been found to cause more deterioration in severe TBI than in patients with mild TBI.

CONCLUSION

Paucity of vitamin D significantly affects the outcome after brain injury. This clearly validates the necessity for screening of vitamin D levels in neurological deficit in order to reduce the risk of morbidity in terms of neurocognitive disorder.

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.

Traumatic Brain Injury as Frequent Cause of Hypopituitarism and Growth Hormone Deficiency: Epidemiology, Diagnosis, and Treatment

Traumatic brain injury (TBI)-related hypopituitarism has been recognized as a clinical entity for more than a century, with the first case being reported in 1918. However, during the 20^th century hypopituitarism was considered only a rare sequela of TBI. Since 2000 several studies strongly suggest that TBI-mediated pituitary hormones deficiency may be more frequent than previously thought. Growth hormone deficiency (GHD) is the most common abnormality, followed by hypogonadism, hypothyroidism, hypocortisolism, and diabetes insipidus. The pathophysiological mechanisms underlying pituitary damage in TBI patients include a primary injury that may lead to the direct trauma of the hypothalamus or pituitary gland; on the other hand, secondary injuries are mainly related to an interplay of a complex and ongoing cascade of specific molecular/biochemical events. The available data describe the importance of GHD after TBI and its influence in promoting neurocognitive and behavioral deficits. The poor outcomes that are seen with long standing GHD in post TBI patients could be improved by GH treatment, but to date literature data on the possible beneficial effects of GH replacement therapy in post-TBI GHD patients are currently scarce and fragmented. More studies are needed to further characterize this clinical syndrome with the purpose of establishing appropriate standards of care. The purpose of this review is to summarize the current state of knowledge about post-traumatic GH deficiency.

Amelioration of cognitive impairment following growth hormone replacement therapy: A case report and review of literature

BACKGROUND

Stroke is one of the leading causes of death and disability worldwide. In patients suffering from strokes and other acute brain injuries, the prevalence of pituitary dysfunction is high, and growth hormone deficiency is commonly found. Previous studies have demonstrated that administration of recombinant human growth hormone provides adult growth hormone deficiency (AGHD) patients with beneficial effects such as improving body compositions and quality of life. Nevertheless, other physiological benefits of growth hormone substitution are still controversial and inconclusive.

CASE SUMMARY

A female with a history of hypertension suffered intracranial hemorrhage, intraventricular hemorrhage, and hydrocephalus at 56 years of age. Her mobility, fluency of speech, and mentality were impaired ever since the event occurred. After five years, the 61-year-old patient was further diagnosed with AGHD and received six-month growth hormone replacement therapy (GHRT). After six months of GHRT, the patient’s body composition was improved. A substantial improvement in Mini-Mental State Examination score was also observed, accompanying with ameliorations in mobility, fluency of speech, and mentality.

CONCLUSION

In addition to improvements in body composition, GHRT for AGHD may provide further beneficial effects in patients with cognitive or motor impairments due to intracerebral hemorrhage.

Mapping the Steroid Response to Major Trauma From Injury to Recovery: A Prospective Cohort Study

CONTEXT

Survival rates after severe injury are improving, but complication rates and outcomes are variable.

OBJECTIVE

This cohort study addressed the lack of longitudinal data on the steroid response to major trauma and during recovery.

DESIGN

We undertook a prospective, observational cohort study from time of injury to 6 months postinjury at a major UK trauma centre and a military rehabilitation unit, studying patients within 24 hours of major trauma (estimated New Injury Severity Score (NISS) > 15).

MAIN OUTCOME MEASURES

We measured adrenal and gonadal steroids in serum and 24-hour urine by mass spectrometry, assessed muscle loss by ultrasound and nitrogen excretion, and recorded clinical outcomes (ventilator days, length of hospital stay, opioid use, incidence of organ dysfunction, and sepsis); results were analyzed by generalized mixed-effect linear models.

FINDINGS

We screened 996 multiple injured adults, approached 106, and recruited 95 eligible patients; 87 survived. We analyzed all male survivors <50 years not treated with steroids (N = 60; median age 27 [interquartile range 24-31] years; median NISS 34 [29-44]). Urinary nitrogen excretion and muscle loss peaked after 1 and 6 weeks, respectively. Serum testosterone, dehydroepiandrosterone, and dehydroepiandrosterone sulfate decreased immediately after trauma and took 2, 4, and more than 6 months, respectively, to recover; opioid treatment delayed dehydroepiandrosterone recovery in a dose-dependent fashion. Androgens and precursors correlated with SOFA score and probability of sepsis.

CONCLUSION

The catabolic response to severe injury was accompanied by acute and sustained androgen suppression. Whether androgen supplementation improves health outcomes after major trauma requires further investigation.

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.

The history of pituitary dysfunction after traumatic brain injury

PURPOSE

To estimate the total number of articles on traumatic brain injury (TBI)-related hypopituitarism and patients (including children and adolescents) with such disorder that were published until now, particularly after the author's review published on April 2000.

METHODS

Review of the literature retrievable on PubMed.

RESULTS

TBI-related hypopituitarism accounts for 7.2% of the whole literature on hypopituitarism published during the 18 years and half between May 2000 and October 2018. As a result, the total number of patients with TBI-related hypopituitarism now approximates 2200. A number of patients, both adults and children, continue to be published as case reports. Articles, including reviews and guidelines, have been published in national languages in order to maximize locally the information on TBI-related hypopituitarism. TBI-related hypopituitarism has been also studied in animals (rodents, cats and dogs).

CONCLUSIONS

The interest for the damage suffered by anterior pituitary as a result of TBI continues to remain high both in the adulthood and childhood.

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.

A clinical and pathophysiological approach to traumatic brain injury-induced pituitary dysfunction

PURPOSE

This review aimed to evaluate the data underlying the pathophysiology of TBI-induced hypothalamo-pituitary dysfunction.

METHODS

Recent literature about the pathophysiology of TBI-induced hypothalamo-pituitary dysfunction reviewed.

RESULTS

Traumatic brain injury (TBI) is a worldwide epidemic that frequently leads to death; TBI survivors tend to sustain cognitive, behavioral, psychological, social, and physical disabilities in the long term. The most common causes of TBI include road accidents, falls, assaults, sports, work and war injuries. From an endocrinological perspective, TBIs are important, because they can cause pituitary dysfunction. Although TBI-induced pituitary dysfunction was first reported a century ago, most of the studies that evaluate this disorder were published after 2000. TBI due to sports and blast injury-related pituitary dysfunction is generally underreported, due to limited recognition of the cases.

CONCLUSION

The underlying pathophysiology responsible for post-TBI pituitary dysfunction is not clear. The main proposed mechanisms are vascular injury, direct traumatic injury to the pituitary gland, genetic susceptibility, autoimmunity, and transient medication effects.

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.

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.

Diffuse traumatic brain injury affects chronic corticosterone function in the rat

As many as 20-55% of patients with a history of traumatic brain injury (TBI) experience chronic endocrine dysfunction, leading to impaired quality of life, impaired rehabilitation efforts and lowered life expectancy. Endocrine dysfunction after TBI is thought to result from acceleration-deceleration forces to the brain within the skull, creating enduring hypothalamic and pituitary neuropathology, and subsequent hypothalamic-pituitary endocrine (HPE) dysfunction. These experiments were designed to test the hypothesis that a single diffuse TBI results in chronic dysfunction of corticosterone (CORT), a glucocorticoid released in response to stress and testosterone. We used a rodent model of diffuse TBI induced by midline fluid percussion injury (mFPI). At 2months postinjury compared with uninjured control animals, circulating levels of CORT were evaluated at rest, under restraint stress and in response to dexamethasone, a synthetic glucocorticoid commonly used to test HPE axis regulation. Testosterone was evaluated at rest. Further, we assessed changes in injury-induced neuron morphology (Golgi stain), neuropathology (silver stain) and activated astrocytes (GFAP) in the paraventricular nucleus (PVN) of the hypothalamus. Resting plasma CORT levels were decreased at 2months postinjury and there was a blunted CORT increase in response to restraint induced stress. No changes in testosterone were measured. These changes in CORT were observed concomitantly with altered complexity of neuron processes in the PVN over time, devoid of neuropathology or astrocytosis. Results provide evidence that a single moderate diffuse TBI leads to changes in CORT function, which can contribute to the persistence of symptoms related to endocrine dysfunction. Future experiments aim to evaluate additional HP-related hormones and endocrine circuit pathology following diffuse TBI.

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.

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.

Update of Endocrine Dysfunction following Pediatric Traumatic Brain Injury

Traumatic brain injuries (TBI) are common occurrences in childhood, often resulting in long term, life altering consequences. Research into endocrine sequelae following injury has gained attention; however, there are few studies in children. This paper reviews the pathophysiology and current literature documenting risk for endocrine dysfunction in children suffering from TBI. Primary injury following TBI often results in disruption of the hypothalamic-pituitary-adrenal axis and antidiuretic hormone production and release, with implications for both acute management and survival. Secondary injuries, occurring hours to weeks after TBI, result in both temporary and permanent alterations in pituitary function. At five years after moderate to severe TBI, nearly 30% of children suffer from hypopituitarism. Growth hormone deficiency and disturbances in puberty are the most common; however, any part of the hypothalamic-pituitary axis can be affected. In addition, endocrine abnormalities can improve or worsen with time, having a significant impact on children’s quality of life both acutely and chronically. Since primary and secondary injuries from TBI commonly result in transient or permanent hypopituitarism, we conclude that survivors should undergo serial screening for possible endocrine disturbances. High indices of suspicion for life threatening endocrine deficiencies should be maintained during acute care. Additionally, survivors of TBI should undergo endocrine surveillance by 6–12 months after injury, and then yearly, to ensure early detection of deficiencies in hormonal production that can substantially influence growth, puberty and quality of life.

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.

Pharmacotherapy of traumatic brain injury: state of the science and the road forward: report of the Department of Defense Neurotrauma Pharmacology Workgroup

Despite substantial investments by government, philanthropic, and commercial sources over the past several decades, traumatic brain injury (TBI) remains an unmet medical need and a major source of disability and mortality in both developed and developing societies. The U.S. Department of Defense neurotrauma research portfolio contains more than 500 research projects funded at more than $700 million and is aimed at developing interventions that mitigate the effects of trauma to the nervous system and lead to improved quality of life outcomes. A key area of this portfolio focuses on the need for effective pharmacological approaches for treating patients with TBI and its associated symptoms. The Neurotrauma Pharmacology Workgroup was established by the U.S. Army Medical Research and Materiel Command (USAMRMC) with the overarching goal of providing a strategic research plan for developing pharmacological treatments that improve clinical outcomes after TBI. To inform this plan, the Workgroup (a) assessed the current state of the science and ongoing research and (b) identified research gaps to inform future development of research priorities for the neurotrauma research portfolio. The Workgroup identified the six most critical research priority areas in the field of pharmacological treatment for persons with TBI. The priority areas represent parallel efforts needed to advance clinical care; each requires independent effort and sufficient investment. These priority areas will help the USAMRMC and other funding agencies strategically guide their research portfolios to ensure the development of effective pharmacological approaches for treating patients with TBI.

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.

[Traumatic brain injury and anterior pituitary dysfunction. Regarding 33 cases: Evolution profile over a six-month period]

OBJECTIVES

To measure anterior pituitary dysfunction in traumatic brain injury (TBI) and assess the correlations between this disorder, clinical signs and brain lesions.

METHOD

This was a prospective, longitudinal and analytic study conducted in the department of neurosurgery at the National Hospital of Niamey and the institute of radioisotopes of Niamey University between November 2009 and November 2010. All patients admitted for head trauma were included in the study. They were followed-up for 6 months and underwent clinical, hormonal and CT scan analysis. The hormonal studies targeted gonadotroph hormone, growth hormone (GH), corticotroph, lactotroph, and thyreotroph axes.

RESULTS

Thirty-three patients were included in the study. The sex ratio was 15.4:1. The mean age was 28.21 years. Glasgow coma scale score was between 7 and 12 in 52% of cases, with brain contusions in 54.5% of cases. In the acute phase, hypogonadism was reported in 64% of cases, and growth hormone deficiency in 58% of cases. Hormonal follow-up at three months showed GH deficiency in 48% of cases with an elevated luteinizing hormone (LH) in 42% of cases. At sixth months, a rise in LH was observed in 55% with GH deficiency in 52% of cases. Surgical procedures were performed in 21% of cases. At 6 months a post-concussion syndrome was observed in 48.48% of cases.

CONCLUSION

These pituitary dysfunctions are common and should be investigated into the management of TBI.

Peptidergic drugs for the treatment of traumatic brain injury

Traumatic brain injury (TBI) is a devastating medical condition that has an enormous socioeconomic impact because it affects more than 10 million people annually worldwide and is associated with high rates of hospitalization, mortality and disability. Although TBI survival has improved continuously for decades, particularly in developing countries, implementation of an effective drug therapy for TBI represents an unmet clinical need. All confirmatory trials conducted to date with drugs targeting a single TBI pathological pathway failed to show clinical efficacy, probably because TBI pathophysiology involves multiple cellular and molecular mechanisms of secondary brain damage. According to current scientific evidence of the participation of peptide-mediated mechanisms in the processes of brain injury and repair after TBI, peptidergic drugs represent a multimodal therapy alternative to improve acute outcome and long-term recovery in TBI patients. Preliminary randomized-controlled clinical trials and open-label studies conducted to date with the peptidergic drug Cerebrolysin® (Ever Neuro Pharma GmbH, Unterach, Austria) and with the endogenous neuropeptides progesterone and erythropoietin, showed positive clinical results. Cerebrolysin-treated patients had a faster clinical recovery, a shorter hospitalization time and a better long-term outcome. Treatment with progesterone showed advantages over placebo regarding TBI mortality and clinical outcome, whereas erythropoietin only reduced mortality. Further validation of these promising findings in confirmatory randomized-controlled clinical trials is warranted. This article reviews the scientific basis and clinical evidence on the development of multimodal peptidergic drugs as a therapeutic option for the effective treatment of TBI patients.

Endocrine changes after pediatric traumatic brain injury

Traumatic brain injury (TBI) is a very common occurrence in childhood, and can lead to devastating long term consequences. Recent research has focused on the potential endocrine consequences of TBI in adults. The research in children is less robust. This paper reviews current literature regarding TBI and possible hypothalamic and pituitary deficiencies in childhood. Acute endocrine changes are commonly found after TBI in pediatric patients, which can include changes in hypothalamic-pituitary-adrenal axis and antidiuretic hormone production and release. In the long term, both temporary and permanent alterations in pituitary function have been found. About 30% of children have hypopituitarism up to 5 years after injury. Growth hormone deficiency and disturbances in puberty are the most common, but children can also experience ACTH deficiency, diabetes insipidus, central hypothyroidism, and elevated prolactin. Every hormonal axis can be affected after TBI in children, although growth hormone deficiency and alterations in puberty are the most common. Because transient and permanent hypopituitarism is common after TBI, survivors should be screened serially for possible endocrine disturbances. These children should undergo routine surveillance at least 1 year after injury to ensure early detection of deficiencies in hormonal production in order to permit normal growth and development.

Lasting pituitary hormone deficiency after traumatic brain injury

Pituitary deficiencies have been reported after traumatic brain injury (TBI) and may contribute to lasting cognitive disorders in this context. In a population of TBI patients with persistent cognitive and/or behavioral disorders, we sought to determine the prevalence of lasting pituitary deficiency and relationships with TBI severity, cognitive disorders, and impairments in activities of daily living (ADL). Fifty-five patients were included (mean age 36.1 years; 46 men) at least 1 year after TBI. They underwent a comprehensive evaluation of pituitary function (basic tests and stimulation), initial TBI severity, and long-term outcomes (cognitive performance, Glasgow Outcome Scale score, impact on ADL, and quality of life [QoL]). We used chi-squared and Mann-Whitney tests to probe for significant (p≤0.05) relationships between pituitary disorders and other parameters. Thirty-eight (69%) patients had at least one pituitary hormone deficiency. Growth hormone deficiency was more prevalent (severe: 40.0%; partial: 23.6%) than corticotropin (27.3%) or thyrotropin (21.8%) deficiencies. Other deficiencies were rare. Growth hormone deficiency was associated with attention and verbal memory disorders and reduced involvement in ADL. We did not find any relationship between pituitary deficiency and the TBI's initial severity. In a multivariate analysis, the TBI severity was introduced as a first factor, and pituitary deficits as a secondary factor for explaining the late outcome (ADL and QoL). In conclusion, TBI patients with cognitive sequelae must undergo pituitary screening because growth hormone, corticotropin, and thyrotropin deficits are particularly common and can adversely affect ADL and reduce QoL.

High prevalence of chronic pituitary and target-organ hormone abnormalities after blast-related mild traumatic brain injury

Studies of traumatic brain injury from all causes have found evidence of chronic hypopituitarism, defined by deficient production of one or more pituitary hormones at least 1 year after injury, in 25–50% of cases. Most studies found the occurrence of posttraumatic hypopituitarism (PTHP) to be unrelated to injury severity. Growth hormone deficiency (GHD) and hypogonadism were reported most frequently. Hypopituitarism, and in particular adult GHD, is associated with symptoms that resemble those of PTSD, including fatigue, anxiety, depression, irritability, insomnia, sexual dysfunction, cognitive deficiencies, and decreased quality of life. However, the prevalence of PTHP after blast-related mild TBI (mTBI), an extremely common injury in modern military operations, has not been characterized. We measured concentrations of 12 pituitary and target-organ hormones in two groups of male US Veterans of combat in Iraq or Afghanistan. One group consisted of participants with blast-related mTBI whose last blast exposure was at least 1 year prior to the study. The other consisted of Veterans with similar military deployment histories but without blast exposure. Eleven of 26, or 42% of participants with blast concussions were found to have abnormal hormone levels in one or more pituitary axes, a prevalence similar to that found in other forms of TBI. Five members of the mTBI group were found with markedly low age-adjusted insulin-like growth factor-I (IGF-I) levels indicative of probable GHD, and three had testosterone and gonadotropin concentrations consistent with hypogonadism. If symptoms characteristic of both PTHP and PTSD can be linked to pituitary dysfunction, they may be amenable to treatment with hormone replacement. Routine screening for chronic hypopituitarism after blast concussion shows promise for appropriately directing diagnostic and therapeutic decisions that otherwise may remain unconsidered and for markedly facilitating recovery and rehabilitation.

Differences in the insulin tolerance test in patients with brain damage depending on posture

OBJECTIVE

The insulin tolerance test (ITT) is the gold standard for the diagnosis of GH deficiency (GHD) and hypocortisolism. As hypopituitarism is a common disorder after traumatic brain injury (TBI) and subarachnoid hemorrhage (SAH), the test is increasingly used in patients with pre-existing brain damage.

DESIGN

A cross-sectional, observational study.

METHODS

Fifty-six patients (41 TBI and 15 SAH) were tested with the ITT (0.15 IE/kg body weight, mean glucose 33 mg/dl). In 38 patients, the test was performed in a supine position; the other 18 patients were in a sitting position during the ITT.

RESULTS

Hypocortisolism and GHD were more often diagnosed in a supine than in a sitting position (hypocortisolism: 55.3% supine versus 0% sitting, P<0.0001; GHD: 42.1% supine versus 11.1% sitting, P=0.03). Patients in a sitting position suffered more often from symptoms such as tachycardia (61.1% sitting versus 15.8% supine, P=0.001), trembling (22.2 vs 7.9%, NS), and sweating (66.7 vs 28.9%, P=0.007). There were no significant differences between the groups in drowsiness (72.2% sitting versus 65.8% supine, NS), dizziness (44.4 vs 44.7%, NS), and fatigue (33.3 vs 15.8%, NS). Because of somnolence, the hypoglycemic state could only be stopped with i.v. administration of glucose in 25 supine patients (66%). In contrast, none of the 18 patients (0%) tested in a sitting position got somnolent or was in need of i.v. application of glucose (P<0.001).

CONCLUSIONS

In patients with brain injury, posture might affect rates of diagnosing GHD and hypocortisolism and sympathetic symptoms in the ITT. These findings are exploratory and need replication in a standardized setting.