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

Efficacy of biomarkers and imaging techniques for the diagnosis of traumatic brain injury: challenges and opportunities

Concussion is a pervasive health issue in the present day. Increased prevalence in recent years has indicated a need to improve the current understanding of minor traumatic brain injury (mTBI). Effort has been devoted to understanding the underlying pathophysiology of TBIs, but some mechanisms remain unknown. Potentially lethal secondary effects of concussion include second impact syndrome and chronic traumatic encephalopathy (CTE), introducing long-term considerations for the management of mTBI. Post-concussion syndrome is another long-term consequence of concussion and may be influenced by both neuroinflammation and hormonal imbalances resulting from head trauma. Genetically mutated apolipoprotein E may also contribute to the severity and persistence of concussion symptoms, perhaps even acting as a risk factor for CTE. As it stands, the diagnosis of concussion is nuanced, depending primarily on subjective diagnostic tools that incorporate patient-reported symptoms and neurocognitive tests. Diagnostic tools provide some assistance in concussion diagnosis, but still lack accuracy and inherently leave room for uncertainty. To mitigate some of this uncertainty, considerable research has been devoted to the development of methods to diagnose concussions objectively. Biomarkers such as S100 calcium binding protein B (S100B), glial fibrillary acidic protein (GFAP), neurofilament light protein (Nf-L), interleukin-6 (IL-6) and microRNAs (miRNAs) as well as imaging techniques including diffusion tensor imaging (DTI) and blood-oxygen level dependent functional magnetic resonance imaging (BOLD-fMRI) show great promise in this regard. This review aims to compile the relevant literature in these areas in the hopes of being used as a reference point for future research regarding concussions.

The interplay between thyrotropic axis, neurological complications, and rehabilitation outcomes in patients with traumatic brain injury

Traumatic brain injury (TBI) is a leading cause of mortality and long-term disability, with its pathophysiology encompassing both primary mechanical damage and secondary neuroinflammatory, metabolic, and biochemical alterations. These complex mechanisms contribute to the observed heterogeneous clinical outcomes, including neuroendocrine dysfunctions, post-traumatic seizures, and disorders of consciousness (DoC). Thyroid hormones (THs) play essential roles in synaptic plasticity, neurogenesis and neuronal homeostasis, and the hypothalamic-pituitary-thyroid (HPT) axis has recently emerged as a potential acute and chronic modulator of neurological and functional recovery following TBI, thereby hinting at the potential involvement of THs in post-TBI outcomes. While evidence suggests that alterations in the HPT axis may influence susceptibility to seizures, progression of DoC, and rehabilitation outcomes, an increased blood-brain barrier permeability in concert with dysregulated deiodinase activity and expanding oxidative stress have all been proposed as mechanisms linking THs to post-TBI neurological complications. This review aims to summarize current evidence on the potential role of the thyrotropic axis in neurological and rehabilitation outcomes following TBI.

Epidemiology and risk factors for hypopituitarism due to traumatic brain injury

During the last two decades traumatic brain injury (TBI) was also found as an important cause of hypopituitarism. Although the most common causes of TBI are traffic accidents and falls, others such as blast-related injuries, acts of violence and combative sports are also considered in the etiology. TBI may lead to transient or permanent pituitary dysfunction. The definition of TBI-induced hypopituitarism cover alterations in pituitary hormone levels which may occur even after five years of injury and characterised by hormonal deficiencies but rarely recovery of some hormones during the course of the disease. It has been shown that between 5 % and 70 % of the TBI patients suffer from hypopituitarism. This large variation in the prevalence may be explained by diverse diagnostic criteria used in different studies, different time points of interventions after TBI, severity of trauma etc. Patients with advanced age, low Glasgow Coma Scale, needing intensive care unit stay, presence of skull fractures, brain edema are particularly make patients vulnerable to TBI-induced hypopituitarism.

Clinical manifestations and treatment of hypopituitarism due to traumatic brain injury

Traumatic brain injury (TBI) is a global health problem with rising incidence. In many patients, pituitary hormone deficiencies after TBI are transient; however, in some cases, they can persist or develop in the chronic phase. Post-traumatic hypopituitarism has a variable clinical course, reflecting its complex pathophysiology and incompletely understood risk factors. The diagnosis can be challenging, because symptoms of hypopituitarism may overlap with other TBI manifestations. Confirmatory endocrine testing is often required for diagnosis. Untreated chronic hypopituitarism can adversely affect physical, neurocognitive, and psychosocial rehabilitation; body composition; glucose metabolism; bone metabolism; and quality of life. Screening for hypopituitarism is recommended after moderate or severe TBI and for selected patients with mild TBI and suggestive clinical symptoms. Management requires an individualized multidisciplinary approach and consideration of endocrine pathology. In this review, we discuss the clinical manifestations and current management standards for hypopituitarism in adults with TBI.

The effects of adrenal insufficiency and its treatment on cognition in an athlete with post-concussion syndrome

Post-concussion Syndrome (PCS) describes persistent nonspecific neurological, cognitive and emotional symptoms following concussion. A young male presented to a sports concussion clinic with persistent symptoms post-injury. Neurocognitive testing found unexpected severe memory impairment. Blood tests for pituitary function returned low cortisol levels secondary to adrenal insufficiency (AI), which was immediately treated. Post-treatment and improvement of cortisol levels, repeat neuropsychology testing demonstrated reliable improvement in memory and processing speed test scores, commensurate with premorbid expectations. This case highlights the importance of a broad diagnostic approach to formulating unexpected persistent PCS symptoms, screening for AI in PCS cases, and completing neurocognitive testing.

Pituitary dysfunction due to sports injuries

Traumatic brain injury (TBI) during sports activities may lead to dysfunction of the pituitary gland. Even mild TBIs have been shown to have the potential to induce pituitary dysfunction. The clinical picture of pituitary dysfunction subsequent to TBIs may mimic the post-TBI period itself. Pituitary hormone deficiencies may improve or new ones may be observed over time. For this reason, hypopituitarism should be considered both during the acute phase and in the recovery period. The most prevalent pituitary hormone deficiency that follows a sports injury is growth hormone (GH) deficiency. Despite the established knowledge regarding the deleterious consequences of GH deficiency in the athletes, the efficacy of replacement therapy remains controversial. Concurrently, given the potential for GH to be utilised for doping purposes, a consensus on the monitoring of these patients remains elusive. There is a necessity for further systematic and large-scale studies on the epidemiology, pathophysiological mechanisms, screening algorithms, and prevention strategies related to sports-related pituitary dysfunction.

Recurrent hyponatremia due to syndrome of inappropriate antidiuresis after traumatic brain injury: two case reports

Background

Transient hyponatremia due to syndrome of inappropriate antidiuresis (SIAD) is a frequent (20-50%) complication of traumatic brain injury (TBI), but it rarely persists or recurs. There are only few published reports of patients suffering from non-transient hyponatremia due to chronic SIAD after TBI. We report two more cases with this condition.

Case 1

A 36-year-old woman suffering from major depression and treated with olanzapine reported severe TBI after a severe fall. Following head injury, she developed severe hyponatremia, which was managed with fluid restriction and salt supplementation. Upon hospital discharge, 7 months after trauma, mild hyponatremia was still reported (Na 134 mmol/L), which dropped to severe hyponatremia in a week despite continuation of treatment, and spontaneously returned to normal. Two months later, the patient presented one more episode of moderate hyponatremia without clear triggering events. Pituitary hormones were normal and urinary sodium and urinary and plasma osmolality supported the diagnosis of SIAD. Therefore, tolvaptan 7.5 mg daily was started, with sustained normalization of sodium levels. When olanzapine was stopped, discontinuation of tolvaptan was attempted. However, serum sodium dropped again and tolvaptan had to be resumed, with natremia remaining within normal range at follow-up. Consistently, olanzapine-related hyponatremia could be ruled out and post-traumatic SIAD confirmed.

Case 2

A 37-year-old man experienced TBI with diffuse axonal injury falling during a mountain trip. Over the following year, he presented two episodes of tonic-clonic seizures accompanied by the biochemical finding of moderate-severe hyponatremia. Hyponatremia resolved following hypertonic (3% NaCl) saline infusion, and valproate treatment was started after the second episode. In the following outpatient visits, a progressive decrease of serum sodium from 141 mmol/L to 132 mmol/L was observed, with other tests consistent with SIAD. Therefore, considering the high risk of recurrent seizures as well as the concomitant treatment with valproate, tolvaptan 7.5 mg every other day was started and normal sodium levels have been maintained since then.

Conclusions

We report two cases of recurrent SIAD following TBI, with multiple hyponatremic episodes after initial presentation. This highlights the importance of long-term follow-up of electrolyte abnormalities after head injury.

Resilience of Spontaneously Hypertensive Rats to Secondary Insults After Traumatic Brain Injury: Immediate Seizures, Survival, and Stress Response

Traumatic brain injury (TBI) is one of the primary causes of mortality and disability, with arterial blood pressure being an important factor in the clinical management of TBI. Spontaneously hypertensive rats (SHRs), widely used as a model of essential hypertension and vascular dementia, demonstrate dysfunction of the hypothalamic-pituitary-adrenal axis, which may contribute to glucocorticoid-mediated hippocampal damage. The aim of this study was to assess acute post-TBI seizures, delayed mortality, and hippocampal pathology in SHRs and normotensive Sprague Dawley rats (SDRs). Male adult SDRs and SHRs were subjected to lateral fluid-percussion injury. Immediate seizures were video recorded, corticosterone (CS) was measured in blood plasma throughout the study, and hippocampal morphology assessed 3 months post-TBI. Acute and remote survival rates were significantly higher in the SHRs compared to the SDRs (overall mortality 0% and 58%, respectively). Immediate seizure duration predicted acute but not remote mortality. TBI did not affect blood CS in the SHRs, while the CS level was transiently elevated in the SDRs, predicting remote mortality. Neuronal cell loss in the polymorph layer of ipsilateral dentate gyrus was found in both the SDRs and SHRs, while thinning of hippocampal pyramidal and granular cell layers were strain- and area-specific. No remote effects of TBI on the density of astrocytes or microglia were revealed. SHRs possess a unique resilience to TBI as compared with normotensive SDRs. SHRs show shorter immediate seizures and reduced CS response to the injury, suggesting the development of long-term adaptative mechanisms associated with chronic hypertension. Though remote post-traumatic hippocampal damage in ipsilateral dentate gyrus is obvious in both SHRs and SDRs, the data imply that physiological adaptations to high blood pressure in SHRs may be protective, preventing TBI-induced mortality but not hippocampal neurodegeneration. Understanding the mechanisms of resilience to TBI may also help improve clinical recommendations for patients with hypertension. Limitation: since more than a half of the SDRs with prolonged immediate seizures or elevated CS 3 days after TBI have died, survivorship bias might hamper correct interpretation of the data.

Circulating Brain-Reactive Autoantibody Profiles in Military Breachers Exposed to Repetitive Occupational Blast

Military breachers are routinely exposed to repetitive low-level blast overpressure, placing them at elevated risk for long-term neurological sequelae. Mounting evidence suggests that circulating brain-reactive autoantibodies, generated following CNS injury, may serve as both biomarkers of cumulative damage and drivers of secondary neuroinflammation. In this study, we compared circulating autoantibody profiles in military breachers (n = 18) with extensive blast exposure against unexposed military controls (n = 19). Using high-sensitivity immunoassays, we quantified IgG and IgM autoantibodies targeting glial fibrillary acidic protein (GFAP), myelin basic protein (MBP), and pituitary (PIT) antigens. Breachers exhibited significantly elevated levels of anti-GFAP IgG (p < 0.001) and anti-PIT IgG (p < 0.001) compared to controls, while anti-MBP autoantibody levels remained unchanged. No significant differences were observed for any IgM autoantibody measurements. These patterns suggest that repetitive blast exposure induces a chronic, adaptive immune response rather than a short-lived acute phase. The elevated IgG autoantibodies highlight the vulnerability of astrocytes, myelin, and the hypothalamic-pituitary axis to ongoing immune-mediated injury following repeated blast insults, likely reflecting sustained blood-brain barrier disruption and neuroinflammatory processes. Our findings underscore the potential of CNS-targeted IgG autoantibodies as biomarkers of cumulative brain injury and immune dysregulation in blast-exposed populations. Further research is warranted to validate these markers in larger, more diverse cohorts, and to explore their utility in guiding interventions aimed at mitigating neuroinflammation, neuroendocrine dysfunction, and long-term neurodegenerative risks in military personnel and similarly exposed groups.

Could low prolactin levels after radiotherapy predict the onset of hypopituitarism?

Both local and external cranial radiotherapy (RT) can induce neurotoxicity and vascular damage of the hypothalamic-pituitary area, which can promote neuroendocrine alterations. While anterior pituitary insufficiency after RT has been extensively characterized, data on the effect of RT on prolactin (PRL) secretion are limited and heterogeneous, with different patterns of PRL behavior described in the literature. A progressive decline in PRL levels, reflecting a time-dependent, slowly evolving radiation-induced damage to the pituitary lactotroph cells has been reported. To date, the association between hypopituitarism and hypoprolactinemia in patients undergoing RT has not yet been fully investigated. The few available data suggest that lower PRL levels can predict an extent damage of the pituitary tissue and a higher degree of hypothalamic dysfunction. However, most studies on the effect of RT on pituitary function do not properly assess PRL secretion, as PRL deficiency is usually detected as part of hypopituitarism and not systematically investigated as an isolated disorder, which may lead to an underestimation of hypoprolactinemia after RT. In addition, the often-inadequate follow-up over a long period of time may contribute to the non-recognition of PRL deficiency after RT. Considering that hypoprolactinemia is associated with various metabolic complications, there is a need to define appropriate diagnostic and management criteria. Therefore, hypoprolactinemia should enter in the clinical investigation of patients at risk for hypopituitarism, mainly in those patients who underwent RT.

Hypoprolactinemia. Does it matter? Redefining the hypopituitarism and return from a mumpsimus : "Absence of proof is not the proof of absence"

Prolactin (PRL) is secreted by the lactotroph cells in the anterior pituitary gland which is under inhibitory control of dopamine. The mature human PRL has more than 300 physiological actions including lactation, reproduction, homeostasis, neuroprotection, behavior, water and electrolyte balance, immunoregulation and embryonic and fetal development. PRL is involved in the growth and development of mammary gland, preparation of the breast for lactation in the postpartum period, synthesis of milk, and maintenance of milk secretion. Abnormalities in the synthesis and secretion of PRL may result in hyperprolactinemia or hypoprolactinemia. Although hyperprolactinemia has been extensively investigated in the literature, because of the subtle or unclearly defined symptoms, hypoprolactinemia is a less-known and neglected disorder. Failure of lactation is a well-known clinical manifestation of hypoprolactinemia. Recent studies reveal that hypoprolactinemia may have some effects beyond lactation such as increased risk for metabolic abnormalities including insulin resistance, abnormal lipid profile, obesity and sexual dysfunction. Very low level of PRL is suggested to be avoided in patients receiving dopamin agonist treatment to prevent unwanted effects of hypoprolactinemia. Another important point is that hypoprolactinemia is not included in the classification of hypopituitarism. Anterior pituitary failure is traditionally classified as isolated, partial and complete (panhypopituitarism) hypopituitarism regardless of prolactin level. Therefore, there are two kinds of panhypopituitarism: panhypopituitarism with normal or high PRL level and panhypopituitarism with low PRL level. In this review, we present two personal cases, discuss the diagnosis of hypoprolactinemia, hypoprolactinemia associated clinical picture and suggest to redefine the classification of hypopituitarism.

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.

Predictive value of neuronal markers for pituitary dysfunction following traumatic brain injury: A preliminary study

PURPOSE

Traumatic brain injury (TBI), a well-known risk factor for pituitary dysfunction, is associated with increased serum neurofilament light chain (NFL), glial fibrillary acidic protein (GFAP), and total tau (t-tau) levels. We aimed to assess the predictive value of these markers and pituitary dysfunction following TBI in a prospective manner.

METHODS

Adult patients following TBI were included. Serum levels of NFL, GFAP, t-tau and pituitary and target hormones were analyzed prospectively during first week and one year after TBI.

RESULTS

Twenty-two patients (17 males, 5 females; mean age 40±15 years) were included in the study. Basal NFL levels correlated positively with length of hospital stay and basal cortisol (r=0.643, P=0.001 and r=0.558, P=0.007, respectively) and negatively with Glasgow Coma Scale (GCS) score and basal IGF-1 levels (r=-0.429, P=0.046 and r=-0.481, P=0.023, respectively), while there was no significant correlation between GFAP, t-tau and hormone levels. NFL, GFAP, and t-tau levels significantly decreased, and none of the patients developed hormone deficiencies one year after TBI. No correlations were detected between basal markers and first year pituitary hormone levels.

CONCLUSION

Serum NFL levels were correlated with hormonal changes during acute phase of TBI reflecting the physiological response to trauma. Larger studies are needed to analyze the associations during chronic phase.

Myxedema Coma as a Presentation of Panhypopituitarism Secondary to Traumatic Brain Injury

Background/Objective: Myxedema coma typically presents with decreased level of consciousness and hypothermia, often due to thyroid pathology. In central causes, normal thyroid-stimulating hormone (TSH) levels may delay diagnosis. The purpose of this report is to describe a patient with a history of head trauma who presented with myxedema coma as a manifestation of panhypopituitarism. Case Report: The admitted patient was a 52-year-old man who presented with mental and physical slowness, drowsiness, and weakness. He also had hypotension, hypoglycemia, and low oxygen saturation. Initial evaluation revealed severe pericardial and bilateral pleural effusions, plasma TSH of 2.42 mU/L (normal range 0.25-5.00 mU/L), and plasma adrenocorticotropic hormone (ACTH) of 7.1 pg/mL (normal range 5.2-40.3 pg/mL). Later, his condition deteriorated with anasarca and coma. Signs of improvement were noted after intravenous corticosteroid administration. A subsequent blood test was conducted, which showed a free thyroxine (FT4) level of 0.14 ng/dL (normal range 0.93-1.70 ng/dL). A cranial magnetic resonance scan revealed posttraumatic lesions. The patient's family later admitted head injuries at home. Treatment with intravenous levothyroxine was initiated, resulting in improvement and subsequent discharge in perfect alertness. Conclusion: Hypopituitarism should be suspected in patients with head trauma and symptoms of hormone deficiency. Advanced clinical forms, such as myxedema coma, may also occur. Pituitary hormone levels might be in the normal range, so target gland hormones should be assessed to reach a diagnosis. In the case of suspected central hypothyroidism, requesting only TSH levels may result in a missed diagnosis. For this reason, both TSH and FT4 levels should be measured when central hypothyroidism is suspected.

Evaluation of pituitary function and metabolic parameters in patients with traumatic maxillofacial fractures

PURPOSE

This study was designed to assess the pituitary functions of patients with traumatic maxillofacial fractures and compare the results with healthy controls.

METHODS

Thirty patients (mean age, 38.14 ± 14.15 years; twenty-six male, four female) with a traumatic maxillofacial fracture at least 12 months ago (mean 27.5 ± 6.5 months) and thirty healthy controls (mean age, 42.77 ± 11.36 years; twenty-five male, five female) were included. None of the patients were unconscious following head trauma, and none required hospitalization in intensive care. Basal pituitary hormone levels of the patients were evaluated. All patients and controls had a glucagon stimulation test and an ACTH stimulation test to evaluate the hypothalamic-pituitary-adrenal axis and the GH-IGF-1 axis.

RESULTS

Five of thirty patients (16.6%) had isolated growth hormone (GH) deficiency based on a glucagon stimulation test (GST). The mean peak GH level after GST in patients with hypopituitarism (0.54 ng/ml) was significantly lower than those without hypopituitarism (7.01 ng/ml) and healthy controls (11.70 ng/ml) (P < 0.001). No anterior pituitary hormone deficiency was found in the patients, except for GH.

CONCLUSION

Our study is the first to evaluate the presence of hypopituitarism in patients with traumatic maxillofacial fractures. Preliminary findings suggest that hypopituitarism and GH deficiency pose significant risks to these patients, particularly during the chronic phase of their trauma. However, these findings need to be validated in larger scale prospective studies with more patients.

Anterior Pituitary Dysfunction After Traumatic Brain Injury: A Prospective Study

OBJECTIVE

Anterior pituitary dysfunction is one of the major causes of disability and morbidity in patients suffering from traumatic brain injury (TBI). The present study was undertaken to evaluate the incidence of anterior pituitary dysfunction in cases of moderate and severe TBI, its value in long-term prognostication, and the factors that predispose to a higher incidence of anterior pituitary dysfunction in acute and chronic phases.

METHODS

This was a prospective cohort study wherein 216 patients with moderate and severe TBI were evaluated within 72 hours of TBI (acute phase) and at 6 months (chronic phase).

RESULTS

At 6 months, out of the 216 patients, 95 patients had expired and 35 patients were lost to follow-up. The remaining 86 patients were evaluated at 6 months. In the acute phase, hypopituitarism was seen in 82.4% patients, thyroid axis deficiency was seen in 57.4% patients, gonadal axis deficiency in 54.2% patients, and adrenal axis deficiency in 13.8% patients. In the chronic phase, hypopituitarism was seen in 59.3% patients, thyroid axis deficiency was seen in 24.4% patients, gonadal axis deficiency in 32.6% patients, and adrenal axis deficiency in 23.3% patients. Patients with thyroid axis deficiency at admission had significant association with a bad modified Rankin Scale score at 6 months.

CONCLUSIONS

Thyroid and gonadotropin axes were most commonly affected and deficiency of at least 1 axis was found in 82.4% patients in the acute phase and 59.3% in the chronic phase. Thyroid axis deficiency had a negative impact on prognosis in post-TBI patients.

The Quartile Levels of Thyroid-stimulating Hormone at Newborn Screening Stratified Risks of Neurodevelopmental Impairment in Extremely Preterm Infants: A Population Cohort Study

BACKGROUND

To evaluate whether thyroid-stimulating hormone (TSH) measured during newborn screening (NBS) at birth and at discharge can be surrogate markers for neurodevelopmental impairment (NDI) in extremely preterm infants.

METHODS

The population cohort enrolled infants born <29 weeks' gestation in 2008-2020 in southern Taiwan. Infants with a maternal history of thyroid disorders and infants who required thyroxine supplementation during hospitalization were excluded. TSH levels measured during NBS at birth and at term-equivalent age (TEA)/discharge were respectively categorized into the lowest quartile, the interquartile range, and the highest quartile, which were correlated to NDI outcomes.

RESULTS

Among 392 patients with paired TSH data, 358 (91%) were prospectively followed until a corrected age of 24 months. At birth, infants with lowest-quartile TSH had higher NDI risks (odds ratio [OR] 2.3; 95% confidence interval [CI], 1.3-4.1, P = 0.004) compared to infants with interquartile-range TSH. Conversely, by TEA/discharge, infants with highest-quartile TSH had increased NDI (OR 1.9; 95% CI, 1.0-3.4, P = 0.03). By paired TSH categories, infants persistently in the lowest TSH quartile (48%; aOR 4.4; 95% CI, 1.4-14.5, P = 0.01) and those with a shift from interquartile range to the highest quartile (32%; aOR 2.7; 95% CI, 1.0-7.4, P = 0.046) had increased NDI risks compared with the reference with consistent interquartile-range TSH.

CONCLUSION

Extremely preterm infants persistently in the lowest-quartile TSH level at birth and at discharge had the highest NDI risk. TSH quartile levels measured during NBS may serve as a population surrogate biomarker for assessing NDI risks in infants born extremely preterm.

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

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

Relationships between vestibular issues, noise sensitivity, anxiety and prolonged recovery from mild traumatic brain injury among adults: a scoping review

BACKGROUND

We investigated the extent of literature and findings on relationships between vestibular issues, noise sensitivity (NS), and anxiety. We were interested in how relationships among these factors impacted adults' recovery three months or more after mild traumatic brain injury (mTBI).

METHODS

We conducted a scoping review to evaluate the extent of evidence linking relationships between vestibular issues, NS and anxiety with recovery after mTBI. Data relating to study characteristics and key findings were extracted and used to inform a critical narrative synthesis of findings.

RESULTS

After screening and full-text review, we included two studies. Both studies considered the combination of vestibular issues, NS and anxiety and mTBI recovery. Vestibular issues, NS and anxiety were all significantly associated with one another and their presence was the strongest indicator that symptoms would extend beyond three-months after mTBI.

CONCLUSION

Few studies have focused on the relationships that vestibular issues, NS and anxiety have with one another and recovery after mTBI. Given the apparent strong relationships between these factors and prolonged recovery, we highlight this as an area warranting further investigation.

Diagnosing and treating the elderly individual with hypopituitarism

Hypopituitarism in the elderly is an underestimated condition mainly due to the non-specific presentation that can be attributed to the effects of aging and the presence of comorbidities. Diagnosis and treatment of hypopituitarism often represent a challenging task and this is even more significant in the elderly. Diagnosis can be insidious due to the physiological changes occurring with aging that complicate the interpretation of hormonal investigations, and the need to avoid some provocative tests that carry higher risks of side effects in this population. Treatment of hypopituitarism has generally the goal to replace the hormonal deficiencies to restore a physiological balance as close as possible to that of healthy individuals but in the elderly this must be balanced with the risks of over-replacement and worsening of comorbidities. Moreover, the benefit of some hormonal replacement therapies in the elderly, including sex hormones and growth hormone, remains controversial.

Morbidities and mortality among hospitalized patients with hypopituitarism: Prevalence, causes and management

Hypopituitarism is a highly heterogeneous multisystem disorder that can have a major impact on long-term morbidity and mortality, but even more so during acute medical conditions requiring hospitalization. Recent studies suggest a significant in-hospital burden with prolonged length of stay, increased rate of intensive care unit (ICU) admission, and initiation of mechanical ventilation - all of which may lead to an increased risk of in-hospital mortality. On the one hand, patients with hypopituitarism are often burdened by metabolic complications, including obesity, hypertension, dyslipidemia, and hyperglycemia, which alone, or in combination, are known to significantly alter relevant physiological mechanisms, including metabolism, innate and adaptive immune responses, coagulation, and wound healing, thereby contributing to adverse in-hospital outcomes. On the other hand, depending on the extent and the number of pituitary hormone deficiencies, early recognition of hormone deficiencies and appropriate management and replacement strategy within a well-organized multidisciplinary team are even stronger determinants of short-term outcomes during acute hospitalization in this vulnerable patient population. This review aims to provide an up-to-date summary of recent advances in pathophysiologic understanding, clinical implications, and recommendations for optimized multidisciplinary management of hospitalized patients with hypopituitarism.

Recognition and Practice of Hypopituitarism After Traumatic Brain Injury and Subarachnoid Hemorrhage in Japan: A Survey

INTRODUCTION

Individuals with traumatic brain injury (TBI) or subarachnoid hemorrhage (SAH) are at a high risk of hypopituitarism, and should benefit from early diagnosis and management. However, data on awareness, attitudes, and practices of physicians treating hypopituitarism post-TBI/SAH are limited. The objectives of this study were to gain an understanding of the awareness of Japanese neurosurgeons and endocrinologists towards hypopituitarism post-TBI/SAH and the need for pituitary function assessments in these patients; and to assess the practices and perspectives of these specialists on screening patients with this condition.

METHODS

An observational, cross-sectional study was performed that included a Web-based survey of practicing neurosurgeons managing ≥ 1 new patients with TBI/SAH per year or endocrinologists with ≥ 1 new patients per year with a history of TBI/SAH.

RESULTS

Of the 316 respondents (201 neurosurgeons [male, 95.5%]; 115 endocrinologists [male, 77.4%]), 75.6% of neurosurgeons and 81.7% of endocrinologists were aware of the probable occurrence of hypopituitarism post-TBI/SAH, and 79% neurosurgeons and 93.8% endocrinologists considered pituitary function impairment after TBI/SAH to be either very important or important. Hypopituitarism after TBI/SAH was recognized as an important concern by both neurosurgeons (79%) and endocrinologists (93.8%). Although many respondents agreed that such patients remain undiagnosed and untreated, pituitary function assessment post-TBI/SAH has only been performed to a limited extent. The awareness that post-TBI/SAH hypopituitarism is often transient and can progress over several weeks or months was lower in neurosurgeons (46.8%) than in endocrinologists (66.1%).

CONCLUSIONS

The level of awareness of hypopituitarism post-TBI/SAH was lower among Japanese neurosurgeons than among endocrinologists. Educational programs and detailed guidance for the diagnosis and treatment of hypopituitarism post-TBI/SAH are warranted.

Evaluation of growth hormone deficiency in women with unexplained infertility

PURPOSE

Growth hormone (GH) has been recognized to play a regulatory role in female reproduction. It has been reported that infertile GH deficient patients regained fertility after GH replacement. The frequency of GH deficiency is not established in patients diagnosed with unexplained infertility. Here, we aim to present the prevalence of GH deficieny in this patient group.

METHODS

We included patients diagnosed with unexplained infertility throughout 18 months. Insulin tolerance test (ITT) and glucagon stimulation tests (GST) were performed and insufficient response to both tests was required for the diagnosis of GH deficiency.

RESULTS

Twenty-five patients were included in the study, the mean age was 27.4 ± 4.5 years and the median duration of infertility was 60 months (min:14, max:120). Two patients were GH deficient according to GST and 14 to ITT. Two patients (8%) showed lack of response on both tests and were diagnosed with GH deficiency.

CONCLUSION

The rate of GH deficiency among women with unexplained infertility was 8% in this preliminary study. There is need for further studies with larger patient groups to verify the results.

Efficient assessment of brain fog and fatigue: Development of the Fatigue and Altered Cognition Scale (FACs)

Debilitating symptoms of fatigue and accompanying "brain fog" are observed among patients with various chronic health conditions. Unfortunately, an efficient and psychometrically sound instrument to assess these co-occurring symptoms is unavailable. Here, we report the development and initial psychometric properties of the Fatigue and Altered Cognition Scale (the FACs), a measure of self-reported central fatigue and brain fog. Traumatic brain injury (TBI) was chosen to model and develop the FACs due to research team expertise and established links between TBI and the symptom complex. Potential items were generated by researchers and clinicians with experience treating these symptoms, drawing from relevant literature and review of patient responses to measures from past and current TBI studies. The 20 candidate items for the FACs-ten each to assess altered cognition (i.e., brain fog) and central fatigue-were formatted on an electronic visual analogue response scale (eVAS) via an online survey. Demographic information and history of TBI were obtained. A total of 519 participants consented and provided usable data (average age = 40.23 years; 73% female), 204 of whom self-reported a history of TBI (75% reported mild TBI). Internal consistency and reliability values were calculated. Confirmatory factor analysis (CFA) examined the presumed two-factor structure of the FACs and a one-factor solution for comparison. A measurement invariance test of the two latent constructs (altered cognition, fatigue) among participants with and without TBI was conducted. All items demonstrated normal distribution. Cronbach's alpha coefficients indicated good internal consistency for both factors (α's = .95). Omega reliability values were favorable (α's = .95). CFA supported the presumed two-factor model and item loadings which outperformed the one-factor model. Measurement invariance found the two-factor structure was consistent between the two groups. Implications of these findings, study limitations, and potential use of the FACs in clinical research and practice are discussed.

Endocrine Dysfunction After Traumatic Brain Injury: An Ignored Clinical Syndrome?

Traumatic brain injury (TBI) incurs substantial health and economic burden, as it is the leading reason for death and disability globally. Endocrine abnormalities are no longer considered a rare complication of TBI. The reported prevalence is variable across studies, depending on the time frame of injury, time and type of testing, and variability in hormonal values considered normal across different studies. The present review reports evidence on the endocrine dysfunction that can occur after TBI. Several aspects, including the pathophysiological mechanisms, clinical consequences/challenges (in the acute and chronic phases), screening and diagnostic workup, principles of therapeutic management, and insights on future directions/research agenda, are presented. The management of hypopituitarism following TBI involves hormonal replacement therapy. It is essential for health care providers to be aware of this complication because at times, symptoms may be subtle and may be mistaken to be caused by brain injury itself. There is a need for stronger evidence for establishing recommendations for optimum management so that they can be incorporated as standard of care in TBI management.

Hypopituitarism after traumatic brain injury in adults: Clinical guidelines of the neuroendocrinology area of the Spanish Society of Endocrinology and Nutrition (SEEN)

Traumatic brain injury (TBI) is associated with hypopituitarism with a variable incidence, depending on the time and methods used to diagnosis, and on factors related to the trauma, such as its severity, its anatomical location and the drugs used in the acute phase. The pituitary gland can be damaged directly by the impact or secondary to factors such as ischemia, inflammation, excitotoxicity or immunity. In acute phases ACTH deficiency is the most relevant, since failure to detect and treat it can compromise the patient's life. Clinical manifestations are typical of each hormone deficient axes, although the combination hypopituitarism-trauma has been associated with cognitive deterioration, worse metabolic profile and greater impairment of quality of life. One of the clinical challenges is to determine which patients benefit from a systematic hormonal evaluation, and therefore from hormone replacement, and what is the appropriate time to do so and the most suitable diagnostic methods.

Saliva Cortisol as a Biomarker of Injury in Youth Sport-Related Concussion

Increasing rates of sport-related concussion (SRC) in youth impose a significant burden on public health systems and the lives of young athletes. Accurate prediction for those likely to develop persistent post-concussion symptomology (PPCS) using a fluid biomarker, reflecting both acute injury and recovery processes, would provide the opportunity for early intervention. Cortisol, a stress hormone released through the hypothalamic-pituitary-adrenal (HPA) axis following injury, may provide a missing physiological link to clinical recovery. This cohort study investigated the change in saliva cortisol following SRC and the association between cortisol and symptom burden in pediatric ice hockey players. Further, the association between cortisol levels and medical clearance to return to play was explored. In total, cortisol samples from 233 players were included; 165 athletes (23.6% female) provided pre-injury saliva and 68 athletes (19.1% female) provided post-SRC saliva samples for cortisol analysis. Quantile (median) regressions were used to compare cortisol between pre-injury and post-SRC groups, and the association between total symptoms (/22) and symptom severity scores (/132) reported on the Sport Concussion Assessment Tool (SCAT)3/SCAT5 and post-SRC cortisol (adjusting for age, sex, history of concussion, and time from injury to sample collection). Results demonstrated significantly lower saliva cortisol in post-SRC athletes compared with the pre-injury group (β = -0.62, 95% confidence interval [CI; -1.08, -0.16], p = 0.009). Post-SRC cortisol was not significantly associated with the SCAT3/SCAT5 symptom totals or symptom severity scores; however, females were found to report more symptoms (β = 6.95, 95% CI [0.35, 13.55], p = 0.040) and greater symptom severity (β = 23.87, 95% CI [9.58, 38.15], p = 0.002) compared with males. Exploratory time-to-event analysis revealed a point estimate suggesting a potential association between low cortisol levels and days to medical clearance to return to play. Although preliminary, these findings suggest that the HPA axis may be dysregulated post-SRC. Further, our exploratory analysis and case presentation of post-injury outliers highlight the need to further research cortisol as a prognostic biomarker to inform individualized sex-specific care after SRC.

Screening for possible hypopituitarism following mild traumatic brain injury: The first all-female study. Who do we need to evaluate further?

BACKGROUND

Studies on hypopituitarism (HP) following mild traumatic brain injury (mTBI) have focused on male populations although women may be more susceptible to the sequelae of mTBI. This is, to the best of our knowledge, the first all-female study screening for HP following mTBI.

OBJECTIVE

Screening for possible HP in female athletes reporting a history of one or more mTBI.

METHODS

Pituitary hormone screening blood tests (SBT) were performed in 133 of the 151 female athletes included. Repeated results outside the reference value (O-RV) were considered abnormal necessitating further endocrinological evaluation.

RESULTS

Repeated SBT were O-RV in 88 women (66.2%). Decreased levels of serum insulin growth factor 1 (S-IGF1) were found in 55.6% of participants and elevated levels of serum prolactin (S-prolactin) in 22.6%. Serum cortisol levels were below the RV in 6.0% and thyroid hormonal levels in 11.3%. Lower age and increased number of mTBI symptoms correlated significantly with the risk of hormonal results O-RV.

CONCLUSION

The majority of the study population had SBT O-RV, warranting further workup of possible HP. Decreased levels of S-IGF1 were most commonly observed followed by elevated S-prolactin possibly indicating hypothalamic-pituitary impairment. Lower age and increased number of symptoms of mTBI may indicate the need to screen for HP.

Isolated anterior pituitary dysfunction in adulthood

Hypopituitarism is defined as a complete or partial deficiency in one or more pituitary hormones. Anterior hypopituitarism includes secondary adrenal insufficiency, central hypothyroidism, hypogonadotropic hypogonadism, growth hormone deficiency and prolactin deficiency. Patients with hypopituitarism suffer from an increased disability and sick days, resulting in lower health status, higher cost of care and an increased mortality. In particular during adulthood, isolated pituitary deficits are not an uncommon finding; their clinical picture is represented by vague symptoms and unclear signs, which can be difficult to properly diagnose. This often becomes a challenge for the physician. Aim of this narrative review is to analyse, for each anterior pituitary deficit, the main related etiologies, the characteristic signs and symptoms, how to properly diagnose them (suggesting an easy and reproducible step-based approach), and eventually the treatment. In adulthood, the vast majority of isolated pituitary deficits are due to pituitary tumours, head trauma, pituitary surgery and brain radiotherapy. Immune-related dysfunctions represent a growing cause of isolated pituitary deficiencies, above all secondary to use of oncological drugs such as immune checkpoint inhibitors. The diagnosis of isolated pituitary deficiencies should be based on baseline hormonal assessments and/or dynamic tests. Establishing a proper diagnosis can be quite challenging: in fact, even if the diagnostic methods are becoming increasingly refined, a considerable proportion of isolated pituitary deficits still remains without a certain cause. While isolated ACTH and TSH deficiencies always require a prompt replacement treatment, gonadal replacement therapy requires a benefit-risk evaluation based on the presence of comorbidities, age and gender of the patient; finally, the need of growth hormone replacement therapies is still a matter of debate. On the other side, prolactin replacement therapy is still not available. In conclusion, our purpose is to offer a broad evaluation from causes to therapies of isolated anterior pituitary deficits in adulthood. This review will also include the evaluation of uncommon symptoms and main etiologies, the elements of suspicion of a genetic cause and protocols for diagnosis, follow-up and treatment.

The Role of Apoptosis and Autophagy in the Hypothalamic-Pituitary-Adrenal (HPA) Axis after Traumatic Brain Injury (TBI)

Traumatic brain injury (TBI) is a major health problem affecting millions of people worldwide and leading to death or permanent damage. TBI affects the hypothalamic-pituitary-adrenal (HPA) axis either by primary injury to the hypothalamic-hypophyseal region or by secondary vascular damage, brain, and/or pituitary edema, vasospasm, and inflammation. Neuroendocrine dysfunctions after TBI have been clinically described in all hypothalamic-pituitary axes. We established a mild TBI (mTBI) in rats by using the controlled cortical impact (CCI) model. The hypothalamus, pituitary, and adrenals were collected in the acute (24 h) and chronic (30 days) groups after TBI, and we investigated transcripts and protein-related autophagy (Lc3, Bcln1, P150, Ulk, and Atg5) and apoptosis (pro-caspase-3, cleaved caspase-3). Transcripts related to autophagy were reduced in the hypothalamus, pituitary, and adrenals after TBI, however, this was not reflected in autophagy-related protein levels. In contrast, protein markers related to apoptosis increased in the adrenals during the acute phase and in the pituitary during the chronic phase. TBI stresses induce a variation of autophagy-related transcripts without modifying the levels of their proteins in the HPA axis. In contrast, protein markers related to apoptosis are increased in the acute phase in the adrenals, which could lead to impaired communication via the hypothalamus, pituitary, and adrenals. This may then explain the permanent pituitary damage with increased apoptosis and inflammation in the chronic phase. These results contribute to the elucidation of the mechanisms underlying endocrine dysfunctions such as pituitary and adrenal insufficiency that occur after TBI. Although the adrenals are not directly affected by TBI, we suggest that the role of the adrenals along with the hypothalamus and pituitary should not be ignored in the acute phase after TBI.

Plants and their Bioactive Compounds as a Possible Treatment for Traumatic Brain Injury-Induced Multi-Organ Dysfunction Syndrome

BACKGROUND & OBJECTIVE

Traumatic brain injury is an outcome of the physical or mechanical impact of external forces on the brain. Thus, the silent epidemic has complex pathophysiology affecting the brain along with extracranial or systemic complications in more than one organ system, including the heart, lungs, liver, kidney, gastrointestinal and endocrine system. which is referred to as Multi-Organ Dysfunction Syndrome. It is driven by three interconnected mechanisms such as systemic hyperinflammation, paroxysmal sympathetic hyperactivity, and immunosuppression-induced sepsis. These multifaceted pathologies accelerate the risk of mortality in clinical settings by interfering with the functions of distant organs through hypertension, cardiac arrhythmias, acute lung injury, neurogenic pulmonary edema, reduced gastrointestinal motility, Cushing ulcers, acute liver failure, acute kidney injury, coagulopathy, endocrine dysfunction, and many other impairments. The pharmaceutical treatment approach for this is highly specific in its mode of action and linked to a variety of side effects, including hallucinations, seizures, anaphylaxis, teeth, bone staining, etc. Therefore, alternative natural medicine treatments are widely accepted due to their broad complementary or synergistic effects on the physiological system with minor side effects.

CONCLUSION

This review is a compilation of the possible mechanisms behind the occurrence of multiorgan dysfunction and reported medicinal plants with organoprotective activity that have not been yet explored against traumatic brain injury and thereby, highlighting the marked possibilities of their effectiveness in the management of multiorgan dysfunction. As a result, we attempted to respond to the hypothesis against the usage of medicinal plants to treat neurodegenerative diseases.

Vitamin D Deficiency and Prognosis after Traumatic Brain Injury with Intracranial Injury: A Multi-Center Observational Study

Vitamin D may be important for neuroprotection after traumatic brain injury (TBI) by modifying the inflammatory response. The objective of this study was to evaluate the association between vitamin D deficiency and functional and survival outcomes in patients with TBI and intracranial injury. This study was a prospective multi-center cohort study conducted on adult TBI patients, with intracranial hemorrhage or diffuse axonal injury confirmed by radiological examination, admitted to five participating emergency departments (EDs) from December 2018 to June 2020. The study outcomes were good functional recovery at hospital discharge and survival at 6-months after injury. The primary exposure was serum vitamin D deficiency (0-10 ng/mL). Multi-level logistic regression analysis was performed to estimate the association between vitamin D deficiency and the study outcomes. Among 606 patients, 101 (16.7%) patients had vitamin D deficiency at the time of ED arrival. Good functional recovery was observed in 65.2% (395/606) of total population, and this proportion was significantly lower in the vitamin D deficiency group than the non-deficiency group (56.4 vs. 66.9%, p = 0.04, adjusted odds ratio (OR; 95% confidence interval [CI]): 0.56 (0.36-0.88)). Overall survival rate at 6 months after injury was 79.5% (434/546), and patients with vitamin D deficiency had significantly lower likelihood of survival at 6 months than patients without deficiency [75.0 vs. 80.3%, adjusted OR (95% CI): 0.59 (0.39-0.89)]. Vitamin D deficiency is associated with poor functional outcomes at hospital discharge and mortality at 6-months after injury in TBI patients with intracranial hemorrhage or diffuse axonal injury.

Brain Trauma, Glucocorticoids and Neuroinflammation: Dangerous Liaisons for the Hippocampus

Glucocorticoid-dependent mechanisms of inflammation-mediated distant hippocampal damage are discussed with a focus on the consequences of traumatic brain injury. The effects of glucocorticoids on specific neuronal populations in the hippocampus depend on their concentration, duration of exposure and cell type. Previous stress and elevated level of glucocorticoids prior to pro-inflammatory impact, as well as long-term though moderate elevation of glucocorticoids, may inflate pro-inflammatory effects. Glucocorticoid-mediated long-lasting neuronal circuit changes in the hippocampus after brain trauma are involved in late post-traumatic pathology development, such as epilepsy, depression and cognitive impairment. Complex and diverse actions of the hypothalamic–pituitary–adrenal axis on neuroinflammation may be essential for late post-traumatic pathology. These mechanisms are applicable to remote hippocampal damage occurring after other types of focal brain damage (stroke, epilepsy) or central nervous system diseases without obvious focal injury. Thus, the liaisons of excessive glucocorticoids/dysfunctional hypothalamic–pituitary–adrenal axis with neuroinflammation, dangerous to the hippocampus, may be crucial to distant hippocampal damage in many brain diseases. Taking into account that the hippocampus controls both the cognitive functions and the emotional state, further research on potential links between glucocorticoid signaling and inflammatory processes in the brain and respective mechanisms is vital.

Endocrine dysregulation in aneurysmal subarachnoid haemorrhage

INTRODUCTION

Aneurysmal Subarachnoid haemorrhage (aSAH) is one of the most common causes of neurocritical care admission. Consistent evidence has been suggestive of endocrine dysregulation in aSAH. This review aims to provide an up-to-date presentation of the available evidence regarding endocrine dysregulation in aneurysmal subarachnoid haemorrhage.

METHODS

A comprehensive literature search was performed using PubMed database. All available evidence related to endocrine dysregulation in hypothalamic-pituitary hormones, adrenal hormones and natriuretic peptides after aSAH, published since 2010, were reviewed.

RESULTS

There have been reports of varying prevalence of dysregulation in hypothalamic-pituitary and adrenal hormones in aSAH. The cause of this dysregulation and its pattern remain unclear. Hypothalamic-pituitary and adrenal dysregulation have been associated with higher incidence of poor neurological outcome and increased mortality. Whilst there is evidence that long-term dysregulation of these axes may also develop, it appears to be less frequent than the acute-phase dysregulation and transient in pattern. Increased levels of catecholamines have been reported in the hyper-acute phase of aSAH with reported inconsistent correlation with the outcomes and the complications of the disease. There is growing evidence that of a causal link between the endocrine dysregulation and the development of hyponatraemia and delayed cerebral ischaemia, in the acute phase of aSAH. However, the pathophysiological mechanism and pattern of endocrine dysregulation which could be causally associated with these complications still remain debatable.

CONCLUSION

The evidence, mainly from small observational and heterogeneous in methodology studies, is suggestive of adverse effects of the endocrine dysregulation on the outcome and the incidence of complications of the disease. However, the cause of this dysregulation and a pathophysiological mechanism that could link its presence with the development of acute complications and the outcome of the aSAH remain unclear. Further research is warranted to elucidate the clinical significance of endocrine dysregulation in subarachnoid haemorrhage.

Post-concussive Dizziness: A Review and Clinical Approach to the Patient

Dizziness is a frequent complaint after head trauma. Among patients who suffer a concussion (mild traumatic brain injury or mTBI), dizziness is second only to headache in symptom frequency. The differential diagnosis of post-concussive dizziness (PCD) can be divided into non-vestibular, central vestibular and peripheral vestibular causes with growing recognition that patients frequently exhibit both central and peripheral findings on vestibular testing. Symptoms that traditionally have been ascribed to central vestibular dysfunction may be due to peripheral dysfunction. Further, our ability to test peripheral vestibular function has improved and has allowed us to identify peripheral disorders that in the past would have remained unnoticed. The importance of the identification of the peripheral component in PCD lies in our ability to remedy the peripheral vestibular component to a much greater extent than the central component. Unfortunately, many patients are not adequately evaluated for vestibular disorders until long after the onset of their symptoms. Among the diagnoses seen as causes for PCD are (1) Central vestibular disorders, (2) Benign Paroxysmal Positional Vertigo (BPPV), (3) Labyrinthine dehiscence/perilymph fistula syndrome, (4) labyrinthine concussion, (5) secondary endolymphatic hydrops, (6) Temporal bone fracture, and (7) Malingering (particularly when litigation is pending). These diagnoses are not mutually exclusive and PCD patients frequently exhibit a combination of these disorders. A review of the literature and a general approach to the patient with post-concussive dizziness will be detailed as well as a review of the above-mentioned diagnostic categories.

Integrated Proteome and Phosphoproteome Analyses Reveal Early- and Late-Stage Protein Networks of Traumatic Brain Injury

Traumatic brain injury (TBI) is a major public health concern all around the world. Accumulating evidence suggests that pathological processes after brain injury continuously evolve. Here, we identified the differentially expressed proteins (DEPs) and differentially expressed phosphoproteins (DEPPs) in the early and late stages of TBI in mice using TMT labeling, enrichment of Phos affinity followed, and high-resolution LC-MS/MS analysis. Subsequently, integrative analyses, including functional enrichment-based clustering analysis, motif analysis, cross-talk pathway/process enrichment analysis, and protein-protein interaction enrichment analysis were performed to further identify the different and similar pathophysiologic mechanisms in the early and late stage. Our work reveals a map of early and late-stage protein networks in TBI, which shed light on useful biomarkers and the underlying mechanisms in TBI and its sequelae.

Sport-Related Concussion Preceding Adrenal Insufficiency and Hypopituitarism

ABSTRACT

A 49-year-old woman with a history of daily inhaled corticosteroid use for asthma presented to a concussion clinic 7 wk after sport-related head injury with headache, visual blurring, dizziness, nausea, fatigue, polydipsia, and polyuria. Examination revealed difficulty with vestibulo-occulomotor testing due to nausea and visual straining. Cranial CT/MR imaging was unremarkable. Laboratory testing revealed critically low serum cortisol, hypernatremia, and urine studies suggesting diabetes insipidus. The patient was referred to the emergency department. Intravenous fluid resuscitation, corticosteroids, and desmopressin led to significant symptomatic relief. She was maintained on oral hydrocortisone after cosyntropin test revealed adrenal insufficiency. Her clinical picture suggested chronic subclinical adrenal suppression from inhaled corticosteroids, which was exacerbated by hypopituitarism possibly from concussion combined with diabetes insipidus. Adrenal insufficiency should be considered in athletes with history of corticosteroid use and endocrine-related symptoms after concussion, because this can create significant morbidity and can mimic traditional symptoms of concussion.

A Multicenter Cohort Study in Patients With Primary Empty Sella: Hormonal and Neuroradiological Features Over a Long Follow-Up

OBJECTIVE

primary empty sella (PES) represents a frequent finding, but data on hormonal alterations are heterogeneous, and its natural history is still unclear. Our aim was to evaluate the pituitary function of patients with PES over a long follow-up.

DESIGN

multicenter retrospective cohort study enrolling patients referred between 1984-2020 to five Pituitary Units, with neuroradiological confirmed PES and a complete hormonal assessment.

METHODS

we analyzed hormonal (including basal and dynamic evaluations), clinical and neuroradiological data collected at diagnosis and at the last visit (at least 6 months of follow-up).

RESULTS

we recruited 402 patients (females=63%, mean age=51.5 ± 16 years) with PES (partial, total, undefined in 66%, 13% and 21%, respectively). Hypopituitarism was present in 40.5% (hypogonadism=20.4%, hypoadrenalism=14.7%, growth hormone deficiency=14.7%, hypothyroidism=10.2%, diabetes insipidus=1.5%; multiple deficiencies=11.4%) and hypeprolactinemia in 6.5%. Interestingly, hormonal alterations were diagnosed in 29% of incidental PES. Hypopituitarism was associated with male sex (p=0.02), suspected endocrinopathy (p<0.001), traumatic brain injury (p=0.003) and not with age, BMI, number of pregnancies and neuroradiological grade. A longitudinal assessment was possible in 166/402 (median follow-up=58 months). In 5/166 (3%), new deficiencies occurred, whereas 14/166 (8.4%) showed a hormonal recovery. A progression from partial to total PES, which was found in 6/98 patients assessed with a second imaging, was the only parameter significantly related to the hormonal deterioration (p=0.006).

CONCLUSIONS

this is the largest cohort of patients with PES reported. Hypopituitarism is frequent (40%) but hormonal deterioration seems uncommon (3%). Patients need to be carefully evaluated at diagnosis, even if PES is incidentally discovered.

Growth hormone deficiency in adults with hypopituitarism-What are the risks and can they be eliminated by therapy?

Growth hormone (GH) deficiency develops early in patients with hypothalamic-pituitary disorders and is therefore common among these patients. GH deficiency in adults is associated with increased morbidity, increased body fat mass, abdominal obesity, dyslipidaemia, reduced exercise capacity, impaired cardiac function as well as reduced self-reported well-being and impaired quality of life. Since recombinant human GH became available as replacement therapy more than 25 years ago, randomised controlled trials and long-term studies, together with meta-analyses, have shown improved outcomes in adult patients with hypopituitarism receiving GH. Many of the features associated with GH deficiency in adults improve, or even normalize, and the safety profile is reassuring. The increased interest in GH deficiency in adults with hypothalamic-pituitary disorders has also contributed to the identification of other factors of importance for an outcome such as the replacement of other pituitary hormone deficiencies, and the management of the underlying hypothalamic-pituitary disease, most commonly a pituitary tumour. In this narrative review, we summarize the burden of GH deficiency in adults with hypopituitarism, the impact of GH replacement on the outcome, as well as safety. Based on currently available data, GH replacement should be considered routine management of adults with hypopituitarism.

Minimizing Ischemia Reperfusion Injury in Xenotransplantation

The recent dramatic advances in preventing "initial xenograft dysfunction" in pig-to-non-human primate heart transplantation achieved by minimizing ischemia suggests that ischemia reperfusion injury (IRI) plays an important role in cardiac xenotransplantation. Here we review the molecular, cellular, and immune mechanisms that characterize IRI and associated "primary graft dysfunction" in allotransplantation and consider how they correspond with "xeno-associated" injury mechanisms. Based on this analysis, we describe potential genetic modifications as well as novel technical strategies that may minimize IRI for heart and other organ xenografts and which could facilitate safe and effective clinical xenotransplantation.

Retracing the tracks for SIAD: hyponatraemia due to post-traumatic brain injury hypopituitarism

Hyponatraemia is common in hospital practice, with the syndrome of inappropriate antidiuresis (SIAD) being the most common underlying aetiology. A relatively less frequent but important cause is adrenal insufficiency (AI). We describe the case of a 63-year-old man who presented with symptomatic hyponatraemia and hypoglycaemia associated with abnormal body movements (ballism). The recent commencement of levothyroxine for newly diagnosed hypothyroidism, followed by fluid restriction for presumed SIAD, led to the worsening of a previously undiagnosed AI. His investigations confirmed central AI in association with thyroid and growth hormone deficiencies. The underlying cause of hypopituitarism, in this case, was a traumatic brain injury He responded well to steroid replacement and fluids. This case highlights that SIAD remains a diagnosis of exclusion, and other causes of hyponatraemia, including AI, should always be considered. Second, levothyroxine treatment without steroid replacement can lead to an adrenal crisis in patients with underlying AI.

Association of Concussion Symptoms With Testosterone Levels and Erectile Dysfunction in Former Professional US-Style Football Players

Question

Are professional US-style football players with a history of multiple concussion symptoms more likely to report indicators of low testosterone levels or erectile dysfunction (ED)?

Findings

In this cross-sectional study of 3409 former players, a monotonically increasing association was found between the number of concussion symptoms and the odds of reporting an indicator of low testosterone level and ED.

Meaning

Concussion symptoms among former football players were associated with low testosterone levels and ED indicators, suggesting that men with a history of head injury may benefit from discussions with their health care clinicians regarding these treatable outcomes.

Importance

Small studies suggest that head trauma in men may be associated with low testosterone levels and sexual dysfunction through mechanisms that likely include hypopituitarism secondary to ischemic injury and pituitary axonal tract damage. Athletes in contact sports may be at risk for pituitary insufficiencies or erectile dysfunction (ED) because of the high number of head traumas experienced during their careers. Whether multiple symptomatic concussive events are associated with later indicators of low testosterone levels and ED is unknown.

Objective

To explore the associations between concussion symptom history and participant-reported indicators of low testosterone levels and ED.

Design, Setting, and Participants

This cross-sectional study of former professional US-style football players was conducted in Boston, Massachusetts, from January 2015 to March 2017. Surveys on past football exposures, demographic factors, and current health conditions were sent via electronic and postal mail to participants within and outside of the United States. Analyses were conducted in Boston, Massachusetts; the data analysis began in March 2018 and additional analyses were performed through June 2019. Of the 13 720 male former players eligible to enroll who were contacted, 3506 (25.6%) responded.

Exposures

Concussion symptom score was calculated by summing the frequency with which participants reported 10 symptoms, such as loss of consciousness, disorientation, nausea, memory problems, and dizziness, at the time of football-related head injury.

Main Outcomes and Measures

Self-reported recommendations or prescriptions for low testosterone or ED medication served as indicators for testosterone insufficiency and ED.

Results

In 3409 former players (mean [SD] age, 52.5 [14.1] years), the prevalence of indicators of low testosterone levels and ED was 18.3% and 22.7%, respectively. The odds of reporting low testosterone levels or ED indicators were elevated for previously established risk factors (eg, diabetes, sleep apnea, and mood disorders). Models adjusted for demographic characteristics, football exposures, and current health factors showed a significant monotonically increasing association of concussion symptom score with the odds of reporting the low testosterone indicator (highest vs lowest quartile, odds ratio, 2.39; 95% CI, 1.79-3.19; P < .001). The ED indicator showed a similar association (highest quartile vs lowest, odds ratio, 1.72; 95% CI, 1.30-2.27; P < .001).

Conclusions and Relevance

Concussion symptoms at the time of injury among former football players were associated with current participant-reported low testosterone levels and ED indicators. These findings suggest that men with a history of head injury may benefit from discussions with their health care clinicians regarding testosterone deficiency and sexual dysfunction.

Menopause, anti-Müllerian hormone and cognition in a cohort of women with persistent symptoms following TBI: a case for future research

Objectives: Primary: To explore anti-Müllerian Hormone (AMH) levels in community dwelling women following TBI. Secondary: To explore the relation of AMH to menstrual cycle, cognition, distress and symptoms of menopause.Setting: Large adult TBI outpatient clinic in Toronto Canada.Research design: Prospective study of 10 women with persistent symptoms who were one or more years post TBI.Methods: Consenting participants provided a serum sample for AMH levels, and completed the Menopause Rating Scale (MRS), Symptom Checklist-90 r (SCL-90 r), Repeatable Battery for the Assessment of Neurological Status (RBANS) and a health questionnaire.Main outcomes and results: This study found lower than expected levels of AMH in 50% of participants relative to age matched norms and 50% of participants experienced new onset of menstrual changes. Also notable were findings of lower-than-expected cognitive scores in women over 35 and reports of menopause-related symptoms across all ages groups.Conclusions: As our understanding of the role of AMH grows, examining changes in this novel biomarker in the long-term post-TBI is warranted. Future research should be sufficiently powered to expand on and validate the study's findings.

Endocrine Responses to Sport-Related Brain Injury in Female Athletes: A Narrative Review and a Call for Action

Sport-related brain injury (SRBI) occurs when a blow to the head causes the brain to move back and forth in the skull, and can lead to neuroendocrine dysfunction. Research has shown that males and females experience and recover from SRBI differently, yet most of what is known regarding diagnosis, treatment, and recovery of SRBI is based on male normative data even though females meet or exceed incidence numbers of SRBIs compared to those of males. Females also have been known to have worse outcomes and a greater number of symptoms following SRBI than males. Research is limited as to why females have worse outcomes, but sex hormones have been suggested as a potential reason. SRBI may cause a dysregulation of the hypothalamic–pituitary–gonadal (HPG) axis, which is responsible for regulating the sex hormones estrogen and progesterone. Initial research has shown that SRBI may suppress estrogen and progesterone, and the concentration of these sex hormones could be indicative of injury severity and recovery trajectory. This review discusses the sex-specific differences in SRBI and also the future direction of research that is needed in order to identify the repercussions of SRBIs for female athletes, which will eventually lead to better clinical treatment, sideline care, and recovery profiles.

Pituitary disease and recovery: How are stem cells involved?

The pituitary gland embodies our endocrine hub and rigorously regulates hormone balances in the body, thereby ruling over vital developmental and physiological processes. Pituitary dysfunction and disease strongly impact the organism's biology. Physical damage, tumour development and ageing all negatively affect pituitary state and functionality. On top of its hormone-producing cells, the pituitary contains a population of stem cells. Not only their physiological role is still largely unknown, also whether or how these stem cells are involved in pituitary disease and recovery from defective functionality remains enigmatic. Here, we summarize what is known on the phenotypical and functional behaviour of pituitary stem cells in diseased or dysfunctional gland, as particularly caused by injury, tumourigenesis and ageing.

Adrenal insufficiency

Adrenal insufficiency (AI) is a condition characterized by an absolute or relative deficiency of adrenal cortisol production. Primary AI (PAI) is rare and is caused by direct adrenal failure. Secondary AI (SAI) is more frequent and is caused by diseases affecting the pituitary, whereas in tertiary AI (TAI), the hypothalamus is affected. The most prevalent form is TAI owing to exogenous glucocorticoid use. Symptoms of AI are non-specific, often overlooked or misdiagnosed, and are related to the lack of cortisol, adrenal androgen precursors and aldosterone (especially in PAI). Diagnosis is based on measurement of the adrenal corticosteroid hormones, their regulatory peptide hormones and stimulation tests. The goal of therapy is to establish a hormone replacement regimen that closely mimics the physiological diurnal cortisol secretion pattern, tailored to the patient's daily needs. This Primer provides insights into the epidemiology, mechanisms and management of AI during pregnancy as well as challenges of long-term management. In addition, the importance of identifying life-threatening adrenal emergencies (acute AI and adrenal crisis) is highlighted and strategies for prevention, which include patient education, glucocorticoid emergency cards and injection kits, are described.