Pituitary imaging abnormalities in patients with and without hypopituitarism after traumatic brain injury

Recent evidence suggests that patients with traumatic brain injury (TBI) are at substantial risk of hypopituitarism. The pathomechanisms, however, are not completely understood yet. Little is known about the association of morphological changes in the sella region with pituitary function in TBI. In this study, we assessed morphological abnormalities of the sella region in patients with TBI and their relation to endocrine function. We studied magnetic resonance (MR) or computed tomography (CT) scans of 22 patients with TBI [17 men, 5 women, age (mean+/-SD) 43.5+/-10.6 yr, time after trauma 17.4 +/-15.0 yr]. Of these, 15 patients had some degree of hypopituitarism. We found abnormalities of the sella region in 80% of the patients with hypopituitarism and 29% of those without hypopituitarism (Fisher's exact test, p=0.032). The most common abnormality was loss of volume or empty sella, followed by native signal inhomogeneities, perfusion deficit, and lack of neurohypophyseal signal. Our results indicate that pituitary imaging abnormalities are more common in TBI patients with hypopituitarism than those without. Both immediate trauma-induced pathology as necrosis and hemorrhage as well as multifactorial mid- to long-term changes may underlie these abnormalities.     

Evaluation of pituitary function after traumatic brain injury in childhood

Objectives Post‐traumatic hypopituitarism is well described amongst adult traumatic brain injury (TBI) survivors. We aimed to determine the prevalence and clinical significance of pituitary dysfunction after head injury in childhood. Design Retrospective exploratory study. Patients: 33 survivors of accidental head injury (27 boys). Mean (range) age at study was 13·4 years (5·4–21·7 years) and median (range) interval since injury 4·3 years (1·4–7·8 years). Functional outcome at study: 15 good recovery, 16 moderate disability, two severe disability. Measurements Early morning urine osmolality and basal hormone evaluation were followed by the gonadotrophin releasing hormone (GnRH) and insulin tolerance (n = 25) or glucagon tests (if previous seizures, n = 8). Subjects were not primed. Head injury details were extracted from patient records. Results No subject had short stature (mean height SD score +0·50, range −1·57 to +3·00). Suboptimal GH responses (<5 μg/l) occurred in six peri‐pubertal boys (one with slow growth on follow‐up) and one postpubertal adolescent (peak GH 3·2 μg/l). Median peak cortisol responses to insulin tolerance or glucagon tests were 538 and 562 nm . Nine of twenty‐five and two of eight subjects had suboptimal responses, respectively, two with high basal cortisol levels. None required routine glucocorticoid replacement. In three, steroid cover was recommended for moderate/severe illness or injury. One boy was prolactin deficient. Other basal endocrine results and GnRH‐stimulated LH and FSH were appropriate for age, sex and pubertal stage. Abnormal endocrine findings were unrelated to the severity or other characteristics of TBI or functional outcome. Conclusions No clinically significant endocrinopathy was identified amongst survivors of accidental childhood TBI, although minor pituitary hormone abnormalities were observed.     

A neurosurgical approach to traumatic brain injury and post-traumatic hypopituitarism

Purpose

Traumatic brain injury (TBI) is a common cause of mortality and major disability worldwide. The initial management often depends on the severity of the injury. Pituitary dysfunction can develop as a sequela of TBI, and can have long-term, debilitating impact on the patients. Early identification and prompt intervention of post-traumatic hypopituitarism (PTHP) is essential to prevent or minimize the adverse consequences of this condition. We hereby provide an overview of the current management of TBI from a neurosurgical standpoint. We then review the pathophysiology and risk factors of developing PTHP, as well as our recommendations for its management.

Methods

A review of current literature on TBI and PTHP, including primary research articles, reviews and clinical guidelines.

Results

The current neurosurgical approach to the management of TBI is presented, followed by the pathophysiology and risk factors of PTHP, as well as our recommendations for its management.

Conclusions

Post-traumatic hypopitutiarism is a serious and potentially debilitating condition that is likely under-recognised and under-diagnosed. From a neurosurgical perspective, we advocate a pragmatic approach, i.e. screening those considered at high risk of developing PTHP based on clinical features and biochemical/endocrinological testings; and referring them to a specialist endocrinologist for further management as indicated.

     

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

OBJECTIVE: Traumatic brain injury (TBI) has been associated with hypopituitarism and GH deficiency. However, TBI-mediated hypopituitarism may be more frequent than previously thought. The present work, performed in patients with severe TBI at least 1 year before, had three aims: (i) to evaluate the prevalence of hypopituitarism, (ii) in particular to evaluate the prevalence of GH deficiency, and (iii) to compare three different tests of GH reserve in this cohort. DESIGN AND PATIENTS: From a nonselected group of 249 patients admitted to our Clinical Centre for severe TBI over the last 5 years, 200 of them answered a custom made questionnaire of symptoms of hypopituitarism enclosed in the invitation letter to participate in the study. A total of 170 (99 men and 14 women), accepted to participate in the study (study cohort); 57 had normal questionnaires and were not further studied, 14 discontinued the study, and 99 attended the hospital for dynamic tests of pituitary hormone deficiencies. From these, 44 subjects with IGF-I in the lower range were tested with GHRH+GHRP-6; ITT; and glucagon tests of GH reserve, on three different occasions. MEASUREMENTS: Pituitary hormones plus IGF-I and target gland hormones were analysed. RESULTS: With regard to the initial cohort of 170 subjects (100%), three (1.7%) showed diabetes insipidus; 10 (5.8%) TSH deficiency, 11 (6.4%) ACTH deficiency and 29 (17%) gonadotrophin deficiency. In 10 subjects (5.8%), GH deficiency was diagnosed by strict criteria. Finally, 15 (8.8%) showed combined deficit of several hormones. CONCLUSION: After severe head trauma, gonadotrophin deficiency was the most common pituitary deficit. GH deficiency showed a prevalence similar to ACTH and TSH deficits, i.e. near 6% of the cohort. Taken together, 24.7% of the subjects studied showed any type of pituitary hormone deficiency.     

Evolving hypopituitarism as a consequence of traumatic brain injury (TBI) in childhood - call for attention

Hypopituitarism is a common complication of TBI in long-term survivors, more frequent than previously realized. It may be partial or complete, sometimes very subtle without visible lesions in hypothalamo-pituitary region and is diagnosed only by biochemical means. Neuroendocrine abnormalities caused by TBI may have significant implications for the recovery and rehabilitation of these patients. The subjects at risk are those who have suffered moderate to severe trauma, although mild intensity trauma may precede hypopituitarism also. Particular attention should be paid to this problem in children and adolescents. We describe a patient with hypopituitarism thought to be idiopathic due to mild head trauma which caused diabetes insipidus in childhood, gradual failure of pituitary hormones during the period of growth and development, and metabolic (dyslipidemia), physical (obesity), and cognitive impairments in the adult period.     

Hypopituitarism after traumatic brain injury

Traumatic brain injury (TBI) is one of the main causes of death and disability in young adults, with consequences ranging from physical disabilities to long-term cognitive, behavioural, psychological and social defects. Post-traumatic hypopituitarism (PTHP) was recognized more than 80 years ago, but it was thought to be a rare occurrence. Recently, clinical evidence has demonstrated that TBI may frequently cause hypothalamic-pituitary dysfunction, probably contributing to a delayed or hampered recovery from TBI. Changes in pituitary hormone secretion may be observed during the acute phase post-TBI, representing part of the acute adaptive response to the injury. Moreover, diminished pituitary hormone secretion, caused by damage to the pituitary and/or hypothalamus, may occur at any time after TBI. PTHP is observed in about 40% of patients with a history of TBI, presenting as an isolated deficiency in most cases, and more rarely as complete pituitary failure. The most common alterations appear to be gonadotropin and somatotropin deficiency, followed by corticotropin and thyrotropin deficiency. Hyper- or hypoprolactinemia may also be present. Diabetes insipidus may be frequent in the early, acute phase post-TBI, but it is rarely permanent. Severity of TBI seems to be an important risk factor for developing PTHP; however, PTHP can also manifest after mild TBI. Accurate evaluation and long-term follow-up of all TBI patients are necessary in order to detect the occurrence of PTHP, regardless of clinical evidence for pituitary dysfunction. In order to improve outcome and quality of life of TBI patients, an adequate replacement therapy is of paramount importance.     

Metabolic alterations in patients who develop traumatic brain injury (TBI)-induced hypopituitarism

ObjectiveHypopituitarism is associated with metabolic alterations but in TBI-induced hypopituitarism data are scanty. The aim of our study was to evaluate the prevalence of naïve hypertension, dyslipidemia, and altered glucose metabolism in TBI-induced hypopituitarism patients.DesignCross-sectional retrospective study in a tertiary care endocrinology center. 54 adult patients encountering a moderate or severe TBI were evaluated in the chronic phase (at least 12 months after injury) after-trauma. Presence of hypopituitarism, BMI, hypertension, fasting blood glucose and insulin levels, oral glucose tolerance test (if available) and a lipid profile were evaluated.ResultsThe 27.8% of patients showed various degrees of hypopituitarism. In particular, 9.3% had total, 7.4% multiple and 11.1% isolated hypopituitarism. GHD was present in 22.2% of patients. BMI was similar between the two groups. Hypopituitaric patients presented a higher prevalence of dyslipidemia (p < 0.01) and altered glucose metabolism (p < 0.005) with respect to non hypopituitaric patients. In particular, triglycerides (p < 0.05) and HOMA-IR (p < 0.02) were higher in hypopituitaric TBI patients.ConclusionsWe showed that long-lasting TBI patients who develop hypopituitarism frequently present metabolic alterations, in particular altered glucose levels, insulin resistance and hypertriglyceridemia. In view of the risk of premature cardiovascular death in hypopituitaric patients, major attention has to been paid in those who encountered a TBI, because they suffer from the same comorbidities and may present other deterioration factors due to complex pharmacological treatments and restriction in participation in life activities and healthy lifestyle.     

Hormonal diseases after traumatic brain injury

Traumatic brain injury represents major medical and social problem in all developed countries. Its incidence is about 200 per 100,000 inhabitants per year. In the acute phase immediately after injury the posterior pituitary dysfunction is well-known. The incidence of severe grossly hypernatremic cases of diabetes insipidus (DI) is about 3%, less severe form of ADH insufficiency was recognized in 21-26%. The syndrome of inappropriate antidiuretic hormone secretion (SIADH) was described in about 14%. These changes are transient in most cases, persisting DI has an incidence of 5-7% and SIADH cases recover almost always. Since the beginning of this century several series evaluating prospectively all patients after moderate to severe TBI have been published. Permanent hypopituitarism was found in one quarter to one half of them. The most common turned out to be the growth hormone (17.6%) and gonadotropic (13.4%) deficiency. Less common is the corticotropic (8.4%) and thyrotropic (4.3%) insufficiency. In the majority of patients an isolated dysfunction was discovered. However, in 9%, a combined failure of two or more HPA axis was present. This paper describes the minimum investigation needed to diagnose hypopituitarism by patients after TBI, who may profit from substitution therapy.     

Recurrent hyponatremia after traumatic brain injury

Dysregulation of the neuroendocrine system is a frequent complication after traumatic brain injury (TBI). Symptoms of these hormonal abnormalities might be subtle and thus easily ignored. Hyponatremia usually indicates underlying disorders that disrupt fluid homeostasis. In most patients with TBI, hyponatremia is a feature of the syndrome of inappropriate antidiuretic hormone (SIADH) secretion due to pituitary dysfunction after head injury. Usually TBI-associated hyponatremia is transient and reversible. We report the case of a 48-year-old man with TBI-associated hyponatremia with delayed recovery and recurrent hyponatremia precipitated by subsequent surgery. In this report, we emphasize the importance of identifying patients with slow recovery of the injured brain, which could complicate with SIADH and acute hyponatremia. Differentiating TBI-associated SIADH from other important causes of hyponatremia such as cerebral salt wasting, and hypocortisonism are also reviewed. Prevention of its recurrence by avoiding further risk is mandatory in managing patients with TBI.     

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.     

Posterior pituitary dysfunction after traumatic brain injury

Disorders of water balance are well recognized after traumatic brain injury (TBI), but there are no reliable data on their true prevalence in post-TBI patients. We aimed to evaluate the prevalence of posterior pituitary dysfunction in a large cohort of survivors of TBI. One hundred two consecutive patients (85 males) who suffered severe or moderate TBI were evaluated for diabetes insipidus (DI) at a median of 17 months (range 6-36 months) after the event, using the 8-h water deprivation test (WDT). Their results were compared against normative data obtained from 27 matched, healthy controls. Patients' medical records were retrospectively reviewed for the presence of abnormalities of salt and water balance in the immediate post-TBI period. Twenty-two patients (21.6%) developed DI in the immediate post-TBI period (acute DI group), of whom five had abnormal WDT on later testing. In total, seven patients (6.9%) had abnormal WDT (permanent DI group), five of whom had partial DI. Patients in the acute and permanent DI groups were more likely to have more severe TBI, compared with the rest of the cohort (P < 0.05). In the immediate post-TBI period, 13 patients (12.9%) had syndrome of inappropriate secretion of antidiuretic hormone, which persisted in one patient, and one other patient developed cerebral salt wasting. Diabetes insipidus and syndrome of inappropriate secretion of antidiuretic hormone were common in the immediate post-TBI period. Permanent DI was present in 6.9% of patients who survived severe or moderate TBI, which is higher than traditionally thought. Identification of patients with partial posttraumatic DI is important because appropriate treatment may reduce morbidity and optimize the potential for recovery.     

Developmental traumatic brain injury decreased brain derived neurotrophic factor expression late after injury

Pediatric traumatic brain injury (TBI) is a major cause of acquired cognitive dysfunction in children. Hippocampal Brain Derived Neurotrophic Factor (BDNF) is important for normal cognition. Little is known about the effects of TBI on BDNF levels in the developing hippocampus. We used controlled cortical impact (CCI) in the 17 day old rat pup to test the hypothesis that CCI would first increase rat hippocampal BDNF mRNA/protein levels relative to SHAM and Na?ve rats by post injury day (PID) 2 and then decrease BDNF mRNA/protein by PID14. Relative to SHAM, CCI did not change BDNF mRNA/protein levels in the injured hippocampus in the first 2 days after injury but did decrease BDNF protein at PID14. Surprisingly, BDNF mRNA decreased at PID 1, 3, 7 and 14, and BDNF protein decreased at PID 2, in SHAM and CCI hippocampi relative to Na?ve. In conclusion, TBI decreased BDNF protein in the injured rat pup hippocampus 14 days after injury. BDNF mRNA levels decreased in both CCI and SHAM hippocampi relative to Na?ve, suggesting that certain aspects of the experimental paradigm (such as craniotomy, anesthesia, and/or maternal separation) may decrease the expression of BDNF in the developing hippocampus. While BDNF is important for normal cognition, no inferences can be made regarding the cognitive impact of any of these factors. Such findings, however, suggest that meticulous attention to the experimental paradigm, and possible inclusion of a Na?ve group, is warranted in studies of BDNF expression in the developing brain after TBI.     

High risk of hypopituitarism after traumatic brain injury: a prospective investigation of anterior pituitary function in the acute phase and 12 months after trauma

CONTEXT: Recent data have demonstrated that traumatic brain injury (TBI)-mediated hypopituitarism could be more frequent than previously known. However, most previous data were obtained from retrospective studies. OBJECTIVES: The aim of this study was to determine 1) the prevalence of anterior pituitary hormone deficiencies in the acute phase of TBI and after 12 months, 2) whether severity of trauma correlated with basal hormone levels, and 3) whether initial hormone deficiencies predicted medium-term hormonal status. DESIGN AND PATIENTS: Fifty-two TBI patients (43 men and nine women) were included in the prospective study. Pituitary function was evaluated within 24 h of admission and after 1 yr. RESULTS: Some 5.8% of the patients had TSH deficiency, 41.6% had gonadotropin deficiency, 9.8% had ACTH deficiency, and 20.4% had GH deficiency (GHD). Twelve months after TBI, 5.8% had TSH deficiency, 7.7% had gonadotropin deficiency, 19.2% had ACTH deficiency, and 37.7% had GHD. Twenty-six patients (50.9%) had at least one anterior pituitary hormone deficiency, 21 patients (41.2%) had isolated hormone deficiencies, and five patients (9.7%) had combined hormone deficiencies. Overall, the pituitary hormone deficiencies recovered in 30 (57.7%) patients after 1 yr, and new pituitary hormone deficiencies were present in 27 (51.9%) patients after 1 yr. CONCLUSIONS: GHD is the most common pituitary deficit 12 months after TBI, and 50.9% of the patients had at least one anterior pituitary hormone deficiency. Pituitary function may improve or worsen in a considerable number of patients over 12 months.     

Pathophysiology of hypopituitarism in the setting of brain injury

The complex pathophysiology of traumatic brain injury (TBI) involves not only the primary mechanical event but also secondary insults such as hypotension, hypoxia, raised intracranial pressure and changes in cerebral blood flow and metabolism. It is increasingly evident that these initial insults as well as transient events and treatments during the early injury phase can impact hypothalamic-pituitary function both acutely and chronically after injury. In turn, untreated pituitary hormonal dysfunction itself can further hinder recovery from brain injury. Secondary adrenal insufficiency, although typically reversible, occurs in up to 50% of intubated TBI victims and is associated with lower systemic blood pressure. Chronic anterior hypopituitarism, although reversible in some patients, persists in 25–40% of moderate and severe TBI survivors and likely contributes to long-term neurobehavioral and quality of life impairment. While the rates and risk factors of acute and chronic pituitary dysfunction have been documented for moderate and severe TBI victims in numerous recent studies, the pathophysiology remains ill-defined. Herein we discuss the hypotheses and available data concerning hypothalamic-pituitary vulnerability in the setting of head injury. Four possible pathophysiological mechanisms are considered: (1) the primary brain injury event, (2) secondary brain insults, (3) the stress of critical illness and (4) medication effects. Although each of these factors appears to be important in determining which hormonal axes are affected, the severity of dysfunction, their time course and possible reversibility, this process remains incompletely understood.     

大鼠创伤性脑损伤后认知行为的变化

目的 建立直接手术损伤大鼠部分脑皮质及海马CA1区的创伤性脑损伤模型,并观察损伤后动物认知行为的改变情况.方法 将大鼠进行脑损伤建模后,于术后11～15 d和26～30 d采用Morris水迷宫的方法评价动物的认知行为变化后,灌杀动物取脑切片,HE染色及尼氏染色观察损伤范围;胶质纤维酸性蛋白(GFAP)免疫组织化学染色观察星型胶质细胞(AST)的活化及胶质瘢痕形成情况;术后5 d行Nestin及GFAP双重免疫荧光染色显示海马内干细胞的激活,并观察损伤边缘的干细胞迁移情况.结果 直接手术损伤部分脑皮质及海马CA1区后,造成了动物认知功能障碍,并且1个月时有自发的认知功能恢复;5 d时星型胶质细胞活化,1个月时胶质瘢痕的形成.结论 本实验采用的模型可成功造成动物认知行为的改变,为组织工程材料的移植治疗脑损伤提供了比较适用的研究模型.     

The history of pituitary dysfunction after traumatic brain injury

Pituitary - 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...     

Predictors of anterior pituitary insufficiency after traumatic brain injury

Background Several studies have reported a high prevalence of hypopituitarism after traumatic brain injury (TBI). Risk stratification is a prerequisite for cost‐effective hormonal screening of these patients. However, it is still unclear which risk factors predispose patients to develop anterior hypopituitarism after TBI. Objective To assess clinical and radiological risk factors for post‐traumatic hypopituitarism. Patients and methods Seventy‐eight consecutive patients (52 men, 26 women; mean age 36·0 years, range 18–65 years) with mild, moderate or severe TBI were studied. Endocrine and clinical parameters were assessed 3 and 12 months after TBI. Results We found diffuse axonal injury, basal skull fracture and older age to be major risk factors of post‐traumatic hypopituitarism. Conclusions We have defined specific risk factors for the development of post‐traumatic hypopituitarism that are consistent with pathophysiological considerations. These findings might help to identify at‐risk patients.