Chronic Endocrinopathies in Traumatic Brain Injury Disease

Management of Medical Complications during the Rehabilitation of Moderate-Severe Traumatic Brain Injury

According to the Centers for Disease Control, in 2019, there were approximately 223,135 hospitalizations in the United States related to traumatic brain injury (TBI). If not managed properly, these patients can suffer complications with significant negative implications with respect to morbidity, mortality, and long-term functional prognosis. It is imperative that medical providers who care for patients with TBI across the entire spectrum of care readily diagnose and treat the sequela associated with moderate-severe brain trauma. This article will focus on some of the key medical issues that providers may encounter during acute inpatient rehabilitation.

The Role of Thyroid Hormone in Neuronal Protection

Thyroid hormone is essential for brain development and brain function in the adult. During development, thyroid hormone acts in a spatial and temporal-specific manner to regulate the expression of genes essential for normal neural cell differentiation, migration, and myelination. In the adult brain, thyroid hormone is important for maintaining normal brain function. Thyroid hormone excess, hyperthyroidism, and thyroid hormone deficiency, hypothyroidism, are associated with disordered brain function, including depression, memory loss, impaired cognitive function, irritability, and anxiety. Adequate thyroid hormone levels are required for normal brain function. Thyroid hormone acts through a cascade of signaling components: activation and inactivation by deiodinase enzymes, thyroid hormone membrane transporters, and nuclear thyroid hormone receptors. Additionally, the hypothalamic-pituitary-thyroid axis, with negative feedback of thyroid hormone on thyrotropin-releasing hormone (TRH) and thyroid-stimulating hormone (TSH) secretion, regulates serum thyroid hormone levels in a narrow range. Animal and human studies have shown both systemic and local reduction in thyroid hormone availability in neurologic disease and after brain trauma. Treatment with thyroid hormone and selective thyroid hormone analogs has resulted in a reduction in injury and improved recovery. This article will describe the thyroid hormone signal transduction pathway in the brain and the role of thyroid hormone in the aging brain, neurologic diseases, and the protective role when administered after traumatic brain injury. © 2021 American Physiological Society. Compr Physiol 11:1-21, 2021.

Distant Organ Damage in Acute Brain Injury

Acute brain injuries pose a great threat to global health, having significant impact on mortality and disability. Patients with acute brain injury may develop distant organ failure, even if no systemic diseases or infection is present. The severity of non-neurologic organs' dysfunction depends on the extremity of the insult to the brain. In this comprehensive review we sought to describe the organ-related consequences of acute brain injuries. The clinician should always be aware of the interplay between central nervous system and non-neurological organs, that is constantly present. Cerebral injury is not only a brain disease, but also affects the body as whole, and thus requires holistic therapeutical approach.

Lifelong consequences of brain injuries during development: From risk to resilience

Traumatic brain injuries in children represent a major public health issue and even relatively mild injuries can have lifelong consequences. However, the outcomes from these injuries are highly heterogeneous, with most individuals recovering fully, but a substantial subset experiencing prolonged or permanent disabilities across a number of domains. Moreover, brain injuries predispose individuals to other kinds of neuropsychiatric and somatic illnesses. Critically, the severity of the injury only partially predicts subsequent outcomes, thus other factors must be involved. In this review, we discuss the psychological, social, neuroendocrine, and autonomic processes that are disrupted following traumatic brain injury during development, and consider the mechanisms the mediate risk or resilience after traumatic brain injury in this vulnerable population.

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 interplay between neuroendocrine and sleep alterations following traumatic brain injury

BACKGROUND

Sleep and endocrine disruptions are prevalent after traumatic brain injury (TBI) and are likely to contribute to morbidity.

OBJECTIVE

To describe the interaction between sleep and hormonal regulation following TBI and elucidate the impact that alterations of these systems have on cognitive responses during the posttraumatic chronic period.

METHODS

Review of preclinical and clinical literature describing long-lasting endocrine dysregulation and sleep alterations following TBI. The bidirectional relationship between sleep and hormones is described. Literature describing co-occurrence between sleep-wake disturbances and hormonal dysregulation will be presented. Review of literature describing cognitive effects of seep and hormones. The cognitive and functional impact of sleep disturbances and hormonal dysregulation is discussed within the context of TBI.

RESULTS/CONCLUSIONS

Sleep and hormonal alterations impact cognitive and functional outcome after TBI. Diagnosis and treatment of these disturbances will impact recovery following TBI and should be considered in the post-acute rehabilitative setting.

Assessment of the role of intracranial hypertension and stress on hippocampal cell apoptosis and hypothalamic-pituitary dysfunction after TBI

In recent years, hypopituitarism caused by traumatic brain injury (TBI) has been explored in many clinical studies; however, few studies have focused on intracranial hypertension and stress caused by TBI. In this study, an intracranial hypertension model, with epidural hematoma as the cause, was used to explore the physiopathological and neuroendocrine changes in the hypothalamic-pituitary axis and hippocampus. The results demonstrated that intracranial hypertension increased the apoptosis rate, caspase-3 levels and proliferating cell nuclear antigen (PCNA) in the hippocampus, hypothalamus, pituitary gland and showed a consistent rate of apoptosis within each group. The apoptosis rates of hippocampus, hypothalamus and pituitary gland were further increased when intracranial pressure (ICP) at 24 hour (h) were still increased. The change rates of apoptosis in hypothalamus and pituitary gland were significantly higher than hippocampus. Moreover, the stress caused by surgery may be a crucial factor in apoptosis. To confirm stress leads to apoptosis in the hypothalamus and pituitary gland, we used rabbits to establish a standard stress model. The results confirmed that stress leads to apoptosis of neuroendocrine cells in the hypothalamus and pituitary gland, moreover, the higher the stress intensity, the higher the apoptosis rate in the hypothalamus and pituitary gland.

A Clinically Relevant Closed-Head Model of Single and Repeat Concussive Injury in the Adult Rat Using a Controlled Cortical Impact Device

Repeat concussions (RC) can result in significant long-term neurological consequences and increased risk for neurodegenerative disease compared with single concussion (SC). Mechanisms underlying this difference are poorly understood and best elucidated using an animal model. To the best of our knowledge, there is no closed-head model in the adult rat using a commercially available device. We developed a novel and clinically relevant closed-head injury (CHI) model of both SC and RC in the adult rat using a controlled cortical impact (CCI) device. Adult rats received either a single or repeat CHI (three injuries, 48 h apart), and acute deficits in sensorimotor and locomotor function (foot fault; open field), memory (novel object), and anxiety (open field; corticosterone [CORT]) were measured. Assessment of cellular pathology was also conducted. Within the first week post-CHI, rats with SC or RC showed similar deficits in motor coordination, decreased locomotion, and higher resting CORT levels. Rats with an SC had memory deficits post-injury day (PID) 3 that recovered to sham levels by PID 7; however, rats with RC continued to show memory deficits. No obvious gross pathology was observed on the cortical surface or in coronal sections. Further examination showed thinning of the cortex and corpus callosum in RC animals compared with shams and increased axonal pathology in the corpus callosum of both SC and RC animals. Our data present a model of CHI that results in clinically relevant markers of concussion and an early differentiation between SC and RC.

Can early clinical parameters predict post-traumatic pituitary dysfunction in severe traumatic brain injury?

BACKGROUND

Post-traumatic hypopituitarism is a major complication after severe head trauma. The aim of our study was to evaluate the possible role of early clinical parameters in the development of endocrine deficits.

METHODS

Data on endocrine function, on-admission clinical-, laboratory-, and ICU-monitored parameters were available in 63 patients of the surviving 86 severe head injury patients (post-resuscitation GCS under 8) treated at one neurosurgical center during a 10-year period.

RESULTS

Hypopituitarism was diagnosed in 68.3 % of the patients. The most frequently affected pituitary axis was the growth hormone (GH): GH deficiency or insufficiency was present in 50.8 %. Central hypogonadism affected 23.8 % of male patients; hypothyroidism and secondary adrenal failure were found in 22.2 and 9.5 % of the investigated population, respectively. Early onset (within 1 year of brain injury) hypopituitarism was found in 24 patients. No connection was found between the development of hypopituitarism and any of the clinical parameters assessed on-admission or at ICU. Significant correlations were found between early endocrine dysfunctions and surgical intervention (OR: 4.64) and the diagnosis of subdural hematoma (OR: 12). In our population, after road traffic accidents, the development of late-onset hypopituitarism was less prevalent (OR: 0.22).

CONCLUSIONS

Since our results do not indicate any reliable predictive parameter for the development of endocrine dysfunction in a cohort of patients with severe traumatic brain injury, regular endocrine screening of this specific patient population seems obligatory.

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.

Chronic impact of traumatic brain injury on outcome and quality of life: a narrative review

Traditionally seen as a sudden, brutal event with short-term impairment, traumatic brain injury (TBI) may cause persistent, sometimes life-long, consequences. While mortality after TBI has been reduced, a high proportion of severe TBI survivors require prolonged rehabilitation and may suffer long-term physical, cognitive, and psychological disorders. Additionally, chronic consequences have been identified not only after severe TBI but also in a proportion of cases previously classified as moderate or mild. This burden affects the daily life of survivors and their families; it also has relevant social and economic costs.

Outcome evaluation is difficult for several reasons: co-existing extra-cranial injuries (spinal cord damage, for instance) may affect independence and quality of life outside the pure TBI effects; scales may not capture subtle, but important, changes; co-operation from patients may be impossible in the most severe cases. Several instruments have been developed for capturing specific aspects, from generic health status to specific cognitive functions. Even simple instruments, however, have demonstrated variable inter-rater agreement.

The possible links between structural traumatic brain damage and functional impairment have been explored both experimentally and in the clinical setting with advanced neuro-imaging techniques. We briefly report on some fundamental findings, which may also offer potential targets for future therapies.

Better understanding of damage mechanisms and new approaches to neuroprotection-restoration may offer better outcomes for the millions of survivors of TBI.

Hypoaminoacidemia Characterizes Chronic Traumatic Brain Injury

Individuals with a history of traumatic brain injury (TBI) are at increased risk for a number of disorders, including Alzheimer's disease, Parkinson's disease, and chronic traumatic encephalopathy. However, mediators of the long-term morbidity are uncertain. We conducted a multi-site, prospective trial in chronic TBI patients (∼18 years post-TBI) living in long-term 24-h care environments and local controls without a history of head injury. Inability to give informed consent was exclusionary for participation. A total of 41 individuals (17 moderate-severe TBI, 24 controls) were studied before and after consumption of a standardized breakfast to determine if concentrations of amino acids, cytokines, C-reactive protein, and insulin are potential mediators of long-term TBI morbidity. Analyte concentrations were measured in serum drawn before (fasting) and 1 h after meal consumption. Mean ages were 44 ± 15 and 49 ± 11 years for controls and chronic TBI patients, respectively. Chronic TBI patients had significantly lower circulating concentrations of numerous individual amino acids, as well as essential amino acids (p = 0.03) and large neutral amino acids (p = 0.003) considered as groups, and displayed fundamentally altered cytokine-amino acid relationships. Many years after injury, TBI patients exhibit abnormal metabolic responses and altered relationships between circulating amino acids, cytokines, and hormones. This pattern is consistent with TBI, inducing a chronic disease state in patients. Understanding the mechanisms causing the chronic disease state could lead to new treatments for its prevention.

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.

Sexual Functioning, Desire, and Satisfaction in Women with TBI and Healthy Controls

Traumatic brain injury (TBI) can substantially alter many areas of a person's life and there has been little research published regarding sexual functioning in women with TBI. Methods. A total of 58 women (29 with TBI and 29 healthy controls) from Neiva, Colombia, participated. There were no statistically significant differences between groups in sociodemographic characteristics. All 58 women completed the Sexual Quality of Life Questionnaire (SQoL), Female Sexual Functioning Index (FSFI), Sexual Desire Inventory (SDI), and the Sexual Satisfaction Index (ISS). Results. Women with TBI scored statistically significantly lower on the SQoL (p < 0.001), FSFI subscales of desire (p < 0.05), arousal (p < 0.05), lubrication (p < 0.05), orgasm (p < 0.05), and satisfaction (p < 0.05), and the ISS (p < 0.001) than healthy controls. Multiple linear regressions revealed that age was negatively associated with some sexuality measures, while months since the TBI incident were positively associated with these variables. Conclusion. These results disclose that women with TBI do not fare as well as controls in these measures of sexual functioning and were less sexually satisfied. Future research is required to further understand the impact of TBI on sexual function and satisfaction to inform for rehabilitation programs.

Interrelation between Neuroendocrine Disturbances and Medical Complications Encountered during Rehabilitation after TBI

Traumatic brain injury is not a discrete event but an unfolding sequence of damage to the central nervous system. Not only the acute phase but also the subacute and chronic period after injury, i.e., during inpatient rehabilitation, is characterized by multiple neurotransmitter alterations, cellular dysfunction, and medical complications causing additional secondary injury. Neuroendocrine disturbances also influence neurological outcome and are easily overlooked as they often present with diffuse symptoms such as fatigue, depression, poor concentration, or a decline in overall cognitive function; these are also typical sequelae of traumatic brain injury. Furthermore, neurological complications such as hydrocephalus, epilepsy, fatigue, disorders of consciousness, paroxysmal sympathetic hyperactivity, or psychiatric-behavioural symptoms may mask and/or complicate the diagnosis of neuroendocrine disturbances, delay appropriate treatment and impede neurorehabilitation. The present review seeks to examine the interrelation between neuroendocrine disturbances with neurological complications frequently encountered after moderate to severe TBI during rehabilitation. Common neuroendocrine disturbances and medical complications and their clinical implications are discussed.

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.