Pituitary pathology in traumatic brain injury: a review

A comprehensive review of the new FIGO classification of ovulatory disorders

BACKGROUND

The World Health Organization (WHO) system for the classification of disorders of ovulation was produced 50 years ago and, by international consensus, has been updated by the International Federation of Gynecology and Obstetrics (FIGO).

OBJECTIVE AND RATIONALE

This review outlines in detail each component of the FIGO HyPO-P (hypothalamic, pituitary, ovarian, PCOS) classification with a concise description of each cause, and thereby provides a systematic method for diagnosis and management.

SEARCH METHODS

We searched the published articles in the PubMed database in the English-language literature until October 2022, containing the keywords ovulatory disorders; ovulatory dysfunction; anovulation, and each subheading in the FIGO HyPO-P classification. We did not include abstracts or conference proceedings because the data are usually difficult to assess.

OUTCOMES

We present the most comprehensive review of all disorders of ovulation, published systematically according to the logical FIGO classification.

WIDER IMPLICATIONS

Improving the diagnosis of an individual's ovulatory dysfunction will significantly impact clinical practice by enabling healthcare practitioners to make a precise diagnosis and plan appropriate management.

Long-term pituitary function and functional and patient-reported outcomes in severe acquired brain injury

OBJECTIVE

Assessment of posttraumatic hypothalamic-pituitary dysfunctions is expected to be the most relevant assessment to offer patients with severe intracranial affection. In this study, we aim to investigate the prevalence of hypopituitarism in patients with severe acquired traumatic brain injury (TBI) compared with nontraumatic brain injury (NTBI) and to relate pituitary insufficiency to functional and patient-reported outcomes.

DESIGN

This is a prospective study.

METHODS

We included patients admitted for inpatient neurorehabilitation after severe TBI (N = 42) and NTBI (N = 18). The patients underwent a pituitary function assessment at a mean of 2.4 years after the injury. Functional outcome was assessed by using Functional Independence Measure and Glasgow Outcome Scale-Extended (both 1 year after discharge from neurorehabilitation) and patient-reported outcome was assessed by using Multiple Fatigue Inventory-20 and EQ-5D-3L.

RESULTS

Hypopituitarism was reported in 10/42 (24%) patients with TBI and 7/18 (39%) patients with NTBI (P = .23). Insufficiencies affected 1 axis in 14/17 (82%) patients (13 hypogonadotropic hypogonadism and 1 growth hormone [GH] deficiency) and 2 axes in 3/17 (18%) patients (1 hypogonadotropic hypogonadism and GH deficiency, and 2 hypogonadotropic hypogonadism and arginin vasopressin deficiency). None had central hypoadrenalism or central hypothyroidism. In patients with both TBI and NTBI, pituitary status was unrelated to functioning and ability scores at 1 year and to patient-reported outcome scores at a mean of 2.4 years after the injury.

CONCLUSION

Patients with severe acquired brain injury may develop long-term hypothalamus-pituitary insufficiency, with an equal occurrence in patients with TBI and NTBI. In both types of patients, mainly isolated deficiencies, most commonly affecting the gonadal axis, were seen. Insufficiencies were unrelated to functional outcomes and patient-reported outcomes, probably reflecting the complexity and heterogeneous manifestations in both patient groups.

Menstrual Cycle Patterns After Concussion in Adolescent Patients

OBJECTIVE

To describe menstrual cycle patterns in adolescents with concussion and investigate whether menstrual cycle phase at injury influenced postconcussion cycle pattern changes or concussion symptoms.

STUDY DESIGN

Data were collected prospectively from patients aged 13-18 years presenting to a specialty care concussion clinic for an initial visit (≤28 days postconcussion) and, if clinically indicated, at a follow-up visit 3-4 months postinjury. Primary outcomes included menstrual cycle pattern change since injury (change/no change), menstrual cycle phase at time of injury (calculated using date of last period before injury), and symptom endorsement and severity, measured by Post-Concussion Symptom Inventory (PCSI). Fisher exact tests were used to determine the association between menstrual phase at injury and change in cycle pattern. Multiple linear regression was used to determine whether menstrual phase at injury was associated with PCSI endorsement and symptom severity, adjusting for age.

RESULTS

Five hundred twelve postmenarchal adolescents were enrolled (age 15.2 ± 1.4 years), with 111 (21.7%) returning for follow-up at 3-4 months. Menstrual pattern change was reported by 4% of patients at initial visit and 10.8% of patients at follow-up. At 3-4 months, menstrual phase at injury was not associated with menstrual cycle changes (P = .40) but was associated with endorsement of concussion symptoms on the PCSI (P = .01).

CONCLUSIONS

At 3-4 months' postconcussion, 1 in 10 adolescents experienced a change in menses. Menstrual cycle phase at injury was associated with postconcussion symptom endorsement. Leveraging a large sample of postconcussion menstrual patterns, this study represents foundational data regarding potential menstrual cycle effects of concussion in female adolescents.

Effect of VEGF on neurological impairment and prognosis of acute cerebral infarction patients: A retrospective case-control study

OBJECTIVE

Due to the complex pathological mechanism of acute cerebral infarction, the role of vascular endothelial growth factor (VEGF) on the disease is not clear. Therefore, a retrospective case-control study was performed to explore the effect of VEGF on neurological impairment and prognosis of acute cerebral infarction patients.

METHOD

A total of 100 patients with acute cerebral infarction admitted to our hospital from April 2021 to April 2022 were selected. Blood samples from all patients would be routinely collected to detect the expression of serum VEGF. Pearson chi-square, Spearman correlation and univariate Logistic regression were used to analyze the clinical data to explore the relationship between VEGF expression and basic information, stroke degree, quality of life, and prognosis of patients. To determine whether VEGF can provide relevant basis for the early prevention and prognostic treatment of acute cerebral infarction. And multivariate logistic regression was used to calculate the odds ratio between each variable and VEGF expression.

RESULTS

Pearson chi-square test and Spearman correlation coefficient showed that sex, degree of stroke, limb convulsions, loss of consciousness, hemiplegia, aphasia, mental functioning score, overall quality of life score, and short-term prognosis were significantly correlated with VEGF expression in 100 patients. Univariate logistic regression was used to describe the ORs and 95% confidence interval of subjects at the univariate level, and the degree of stroke (OR = 83.333, P < 0.001), tic of limbs (OR = 26.316, P < 0.001), loss of consciousness (OR = 23.256, P < 0.001), hemiplegia (OR = 62.500, P < 0.001), aphasia (OR = 76.923, P < 0.001), mental functioning score (OR = 7.937, P < 0.001), overall quality of life score (OR = 5.464, P < 0.001), short-term prognosis (OR = 37.037, P < 0.001) was significantly correlated with the high expression of VEGF.

CONCLUSIONS

The level of serum VEGF was positively correlated with neurological impairment degree and prognosis in patients with acute cerebral infarction, the more severe the degree of stroke and the worse the prognosis.

An Approach to Traumatic Brain Injury-Related Hypopituitarism: Overcoming the Pediatric Challenges

Traumatic brain injury (TBI)-related hypopituitarism is a rare polymorphic complication of brain injury, with very little data, particularly concerning children and teenagers. This is a comprehensive review of the literature regarding this pathology, starting from a new pediatric case. The research was conducted on PubMed and included publications from the last 22 years. We identified nine original studies on the pediatric population (two case reports and seven studies; only four of these seven were prospective studies). TBI-related hypopituitarism is associated with isolated hormonal deficits ranging from 22.5% to 86% and multiple hormonal deficiencies from 5.9% to 50% in the studied pediatric population. Growth hormone (GH) deficiency is most often found, including the form with late occurrence after TBI; it was described as persistent in half of the studies. Thyroid-stimulating hormone (TSH) deficiency is identified as a distant complication following TBI; in all three studies, we identified this complication was found to be permanent. Adrenocorticotropic hormone (ACTH) deficiency did not relate to a certain type of brain trauma, and it was transient in reported cases. Hyperprolactinemia was the most frequent hormonal finding, also occurring late after injury. Central diabetes insipidus was encountered early post-TBI, typically with a transient pattern and did not relate to a particular type of injury. TBI-related hypopituitarism, although rare in children, should be taken into consideration even after a long time since the trauma. A multidisciplinary approach is needed if the patient is to safely overcome any acute condition.

Biomechanics of Traumatic Head and Neck Injuries on Women: A State-of-the-Art Review and Future Directions

The biomechanics of traumatic injuries of the human body as a consequence of road crashes, falling, contact sports, and military environments have been studied for decades. In particular, traumatic brain injury (TBI), the so-called "silent epidemic", is the traumatic insult responsible for the greatest percentage of death and disability, justifying the relevance of this research topic. Despite its great importance, only recently have research groups started to seriously consider the sex differences regarding the morphology and physiology of women, which differs from men and may result in a specific outcome for a given traumatic event. This work aims to provide a summary of the contributions given in this field so far, from clinical reports to numerical models, covering not only the direct injuries from inertial loading scenarios but also the role sex plays in the conditions that precede an accident, and post-traumatic events, with an emphasis on neuroendocrine dysfunctions and chronic traumatic encephalopathy. A review on finite element head models and finite element neck models for the study of specific traumatic events is also performed, discussing whether sex was a factor in validating them. Based on the information collected, improvement perspectives and future directions are discussed.

New developments and concepts in the diagnosis and management of diabetes insipidus (AVP-deficiency and resistance)

Diabetes insipidus (DI) is a disorder characterised by the excretion of large amounts of hypotonic urine, with a prevalence of 1 per 25,000 population. Central DI (CDI), better now referred to as arginine vasopressin (AVP)-deficiency, is the most common form of DI resulting from deficiency of the hormone AVP from the pituitary. The less common nephrogenic DI (NDI) or AVP-resistance develops secondary to AVP resistance in the kidneys. The majority of causes of DI are acquired, with CDI developing when more than 80% of AVP-secreting neurons are damaged. Inherited/familial CDI causes account for approximately 1% of cases. Although the pathogenesis of NDI is unclear, more than 280 disease-causing mutations affecting the AVP2 protein or AVP V2 receptor, as well as in aquaporin 2 (AQP2), have been described. Although the cAMP/protein kinase A pathway remains the major regulatory pathway of AVP/AQP2 action, in vitro data have also revealed additional cAMP independent pathways of NDI pathogenesis. Diagnosing partial forms of DI, and distinguishing them from primary polydipsia, can be challenging, previously necessitating the use of the water deprivation test. However, measurements of circulating copeptin levels, especially after stimulation, are increasingly replacing the classical tests in clinical practice because of their ease of use and high sensitivity and specificity. The treatment of CDI relies on desmopressin administration, whereas NDI requires the management of any underlying diseases, removal of offending drugs and, in some cases, administration of diuretics. A better understanding of the pathophysiology of DI has led to novel evolving therapeutic agents that are under clinical trial.

Relation of Mild Traumatic Brain Injury history to abnormalities on a preliminary Neuroendocrine screen; A multicenter LIMBIC-CENC analysis

PRIMARY OBJECTIVES

Determine if an abnormal preliminary neuroendocrine disorder (NED) blood test screen is associated with mild TBI (mTBI) history or post-concussiveclinical features.

RESEARCH DESIGN

Observational.

METHODS

Among 1,520 participants with military combatexposure, we measured randomly timed serum levels of insulin-likegrowth factor-1, thyroid stimulating hormone (TSH), and total testosterone as a preliminary NED screen. Using multivariable models, we analyzed relation of screen results in mTBI group membership and post-concussiveclinical features (fatigue, depression, cognitive symptoms, executive function, processing speed).

RESULTS

None of the mTBI positive groups, including repetitive (≥3 mTBI) and blast-related,differed from the non-TBIcontrols on rates of abnormal lab screen or rates of growth hormone deficiency (GHD), hypothyroidism or male hypogonadism in treatment records. Lab screen findings were also not associated with any clinical feature.

CONCLUSIONS

This study shows no evidence that remote mTBI(s) or implicated post-concussiveclinical features are linked to GHD, hypothyroidism or male hypogonadism. Large case-controlstudies incorporating more definitive neuroendocrine disorder NED testing (TSH plus thyroxine, early morning testosterone, LH, FSH, prolactin and GH provocative testing) are needed to determine whether mTBI(s) alone elevate one's risk for chronic NED and how best to select patients for comprehensive testing.

Association between perceived distress and salivary cortisol in veterans with mTBI

Mild traumatic brain injury (mTBI) is one of the most common injuries experienced by Veterans and can frequently result in a variety of post-concussive symptoms. Post-concussive headaches (PCH), one of the most common symptoms, can persist for years after the injury occurred. The long-lasting impacts of PCH can be extremely distressing for Veterans, thus necessitating the need to find reliable biomarkers that directly relate to subjective feelings of distress. Yoga-based interventions have been shown to improve both subjective and objective markers of stress. Techniques used in yoga, such as the focus on releasing muscular tension, are also recommended as strategies for treating PCH. Thus, yoga-based interventions provide a unique context for the comparison of subjective and objective measures of distress in Veterans with PCH. In this secondary, exploratory analysis, we examined the relationship between perceived distress and cortisol in sixteen Veterans with mTBI and long-term PCH within the context of a yoga intervention feasibility study. The Visual Analogue Scale (VAS), a validated tool for measuring subjective distress, was administered to participants immediately before and after 75-min yoga classes, which occurred twice weekly over eight weeks. Participants also provided salivary cortisol (pre- and post-yoga) at in-person sessions (eight) to compare to changes in VAS scores. We found that VAS scores were significantly reduced within five of the eight assessed yoga classes, but there were no significant changes in cortisol levels. No significant correlations were found between VAS scores and salivary cortisol levels. When looking at how cortisol levels changed over time (i.e., over the series of eight yoga sessions), there was a significant downward trajectory in post-yoga cortisol, but not after taking pre-class cortisol into account (i.e., within yoga session cortisol change over time). Taken together, we found that subjective distress, but not cortisol was reduced by yoga classes. These data suggest that salivary cortisol did not match changes in perceived distress, thus emphasizing the ongoing challenges of relating subjective and objective measures.

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Perceived distress can negatively impact post-concussive symptoms.

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Efforts are needed to relate objective and subjective measures of distress.

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Subjective distress and salivary cortisol were examined within yoga sessions.

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Subjective distress, but not cortisol was reduced within 5 of 8 yoga classes.

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These data highlight the challenges of relating subjective and objective measures.

Repeated mild traumatic brain injury impairs fracture healing in male mice

Objectives

The goal of this study was to evaluate the long-term impact of repeated (r) mild traumatic brain injury (mTBI) on the healing of fractures in a mouse model. Ten week-old male mice were subjected to r-mTBI once per day for 4 days followed by closed femoral fracture using a three-point bending technique, 1 week post impact and fracture healing phenotype evaluated at 20 weeks of age.

Results

Micro-CT analysis of the fracture callus region at nine weeks post fracture revealed reduced bone volume (30%, p < 0.05) in the r-mTBI fracture group compared to the control-fracture group. The connectivity density of the fracture callus bone was reduced by 40% (p < 0.01) in the r-mTBI fracture group. Finite element analysis of the fracture callus region showed reduced failure load (p = 0.08) in the r-mTBI group compared to control group. There was no residual cartilage in the fracture callus region of either the r-mTBI or control fracture group. The reduced fracture callus bone volume and mechanical strength of fracture callus in r-mTBI mice 9 weeks post fracture are consistent with negative effects of r-mTBI on fracture healing over a long-term resulting in decreased mechanical strength of the fracture callus.

Permanent central diabetes insipidus after traumatic brain injury. Case report and literature review

The authors report permanent central diabetes insipidus (CDI) in a patient after severe traumatic brain injury (TBI) in traffic accident. A 16-year-old boy entered to a medical facility in coma (GCS score 6) with the following diagnosis: acute TBI, severe cerebral contusion, subarachnoid hemorrhage, depressed comminuted cranial vault fracture, basilar skull fracture, visceral contusion. CDI was diagnosed in 3 days after injury considering polyuria and hypernatremia (155 mmol/l). Desmopressin therapy was initiated through a feeding tube. Thirst appeared when a patient came out of the coma after 21 days despite ongoing desmopressin therapy. Considering persistent thirst and polyuria, we continued desmopressin therapy in a spray form. Under this therapy, polyuria reduced to 3-3.5 liters per a day. Symptoms of CDI persisted in long-term period (2 years after TBI) while function of adenohypophysis was intact. This case demonstrates a rare development of permanent diabetes insipidus after TBI. CDI manifested only as polyuria and hypernatremia in coma. Thirst joined after recovery of consciousness. Probable causes of CDI were damage to neurohypophysis and partially injury of pituitary stalk because of extended basilar skull fracture and/or irreversible secondary lesion of hypothalamus following diffuse axonal damage after TBI.

Persisting neuroendocrine abnormalities and their association with physical impairment 5 years after critical illness

Background

Critical illness is hallmarked by neuroendocrine alterations throughout ICU stay. We investigated whether the neuroendocrine axes recover after ICU discharge and whether any residual abnormalities associate with physical functional impairments assessed 5 years after critical illness.

Methods

In this preplanned secondary analysis of the EPaNIC randomized controlled trial, we compared serum concentrations of hormones and binding proteins of the thyroid axis, the somatotropic axis and the adrenal axis in 436 adult patients who participated in the prospective 5-year clinical follow-up and who provided a blood sample with those in 50 demographically matched controls. We investigated independent associations between any long-term hormonal abnormalities and physical functional impairments (handgrip strength, 6-min walk distance, and physical health-related quality-of-life) with use of multivariable linear regression analyses.

Results

At 5-year follow-up, patients and controls had comparable serum concentrations of thyroid-stimulating hormone, thyroxine (T₄), triiodothyronine (T₃) and thyroxine-binding globulin, whereas patients had higher reverse T₃ (rT₃, p = 0.0002) and lower T₃/rT₃ (p = 0.0012) than controls. Patients had comparable concentrations of growth hormone, insulin-like growth factor-I (IGF-I) and IGF-binding protein 1 (IGFBP1), but higher IGFBP3 (p = 0.030) than controls. Total and free cortisol, cortisol-binding globulin and albumin concentrations were comparable for patients and controls. A lower T₃/rT₃ was independently associated with lower handgrip strength and shorter 6-min walk distance (p ≤ 0.036), and a higher IGFBP3 was independently associated with higher handgrip strength (p = 0.031).

Conclusions

Five years after ICU admission, most hormones and binding proteins of the thyroid, somatotropic and adrenal axes had recovered. The residual long-term abnormality within the thyroid axis was identified as risk factor for long-term physical impairment, whereas that within the somatotropic axis may be a compensatory protective response. Whether targeting of the residual abnormality in the thyroid axis may improve long-term physical outcome of the patients remains to be investigated.

Trial registration ClinicalTrials.gov: NCT00512122, registered on July 31, 2007 (https://www.clinicaltrials.gov/ct2/show/NCT00512122).

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03858-1.

Mechanisms of Central Hypogonadism

Reproductive function depends upon an operational hypothalamo–pituitary–gonadal (HPG) axis. Due to its role in determining survival versus reproductive strategies, the HPG axis is vulnerable to a diverse plethora of signals that ultimately manifest with Central Hypogonadism (CH) in all its many guises. Acquired CH can result from any pituitary or hypothalamic lesion, including its treatment (such as surgical resection and/or radiotherapy). The HPG axis is particularly sensitive to the suppressive effects of hyperprolactinaemia that can occur for many reasons, including prolactinomas, and as a side effect of certain drug therapies. Physiologically, prolactin (combined with the suppressive effects of autonomic neural signals from suckling) plays a key role in suppressing the gonadal axis and establishing temporary CH during lactation. Leptin is a further key endocrine regulator of the HPG axis. During starvation, hypoleptinaemia (from diminished fat stores) results in activation of hypothalamic agouti-related peptide neurons that have a dual purpose to enhance appetite (important for survival) and concomitantly suppresses GnRH neurons via effects on neural kisspeptin release. Obesity is associated with hyperleptinaemia and leptin resistance that may also suppress the HPG axis. The suppressibility of the HPG axis also leaves it vulnerable to the effects of external signals that include morphine, anabolic-androgenic steroids, physical trauma and stress, all of which are relatively common causes of CH. Finally, the HPG axis is susceptible to congenital malformations, with reports of mutations within >50 genes that manifest with congenital CH, including Kallmann Syndrome associated with hyposmia or anosmia (reduction or loss of the sense of smell due to the closely associated migration of GnRH with olfactory neurons during embryogenesis). Analogous to the HPG axis itself, patients with CH are often vulnerable, and their clinical management requires both sensitivity and empathy.

Therapies to Restore Consciousness in Patients with Severe Brain Injuries: A Gap Analysis and Future Directions

Background/Objective

For patients with disorders of consciousness (DoC) and their families, the search for new therapies has been a source of hope and frustration. Almost all clinical trials in patients with DoC have been limited by small sample sizes, lack of placebo groups, and use of heterogeneous outcome measures. As a result, few therapies have strong evidence to support their use; amantadine is the only therapy recommended by current clinical guidelines, specifically for patients with DoC caused by severe traumatic brain injury. To foster and advance development of consciousness-promoting therapies for patients with DoC, the Curing Coma Campaign convened a Coma Science Work Group to perform a gap analysis.

Methods

We consider five classes of therapies: (1) pharmacologic; (2) electromagnetic; (3) mechanical; (4) sensory; and (5) regenerative. For each class of therapy, we summarize the state of the science, identify gaps in knowledge, and suggest future directions for therapy development.

Results

Knowledge gaps in all five therapeutic classes can be attributed to the lack of: (1) a unifying conceptual framework for evaluating therapeutic mechanisms of action; (2) large-scale randomized controlled trials; and (3) pharmacodynamic biomarkers that measure subclinical therapeutic effects in early-phase trials. To address these gaps, we propose a precision medicine approach in which clinical trials selectively enroll patients based upon their physiological receptivity to targeted therapies, and therapeutic effects are measured by complementary behavioral, neuroimaging, and electrophysiologic endpoints.

Conclusions

This personalized approach can be realized through rigorous clinical trial design and international collaboration, both of which will be essential for advancing the development of new therapies and ultimately improving the lives of patients with DoC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12028-021-01227-y.

Prognostic Value of Circadian Rhythm of Brain Temperature in Traumatic Brain Injury

Hypothermia has been used in postoperative management of traumatic brain injury (TBI); however, the rhythmic variation and prognostic value of brain temperature after TBI have never been studied. This study describes diurnal brain temperature patterns in comatose patients with TBI. Mesors of brain temperature, amplitude, and acrophase were estimated from recorded temperature measurements using cosinor analysis. The association of these patterns with clinical parameters, mortality, and functional outcomes in a 12-month follow-up was examined. According to the cosinor analysis, 59.3% of patients presented with circadian rhythms of brain temperature in the first 72 h postoperatively. The rhythm-adjusted mesor of brain temperature was 37.39 ± 1.21 °C, with a diminished mean amplitude of 0.28 (±0.25) °C; a shift of temperature acrophase was also observed. Multivariate logistic regression analysis revealed that initial Glasgow coma scale score, age, elevated blood glucose level, and circadian rhythm of brain temperature seemed to be predictive and prognostic factors of patients' functional outcomes. For the prediction of survival status, younger patients or those patients with mesor within the middle 50% of brain temperature were more likely to survive. The analysis of brain temperature rhythms in patients with moderate and severe TBI provided additional predictive information related to mortality and functional outcomes.

Ten physiological commandments for severe head injury

Advances in multiparametric brain monitoring have allowed us to deepen our knowledge of the physiopathology of head injury and how it can be treated using the therapies available today. It is essential to understand and interpret a series of basic physiological and physiopathological principles that, on the one hand, provide an adequate metabolic environment to prevent worsening of the primary brain injury and favour its recovery, and on the other hand, allow therapeutic resources to be individually adapted to the specific needs of the patient. Based on these notions, this article presents a decalogue of the physiological objectives to be achieved in brain injury, together with a series of diagnostic and therapeutic recommendations for achieving these goals. We emphasise the importance of considering and analysing the physiological variables involved in the transport of oxygen to the brain, such as cardiac output and arterial oxygen content, together with their conditioning factors and possible alterations. Special attention is paid to the basic elements of physiological neuroprotection, and we describe the multiple causes of cerebral hypoxia, how to approach them, and how to correct them. We also examine the increase in intracranial pressure as a physiopathological element, focussing on the significance of thoracic and abdominal pressure in the interpretation of intracranial pressure. Treatment of intracranial pressure should be based on a step-wise model, the first stage of which should be based on a physiopathological reflection combined with information on the tomographic lesions rather than on rigid numerical values.

Ten physiological commandments for severe head injury

Advances in multiparametric brain monitoring have allowed us to deepen our knowledge of the physiopathology of head injury and how it can be treated using the therapies available today. It is essential to understand and interpret a series of basic physiological and physiopathological principles that, on the one hand, provide an adequate metabolic environment to prevent worsening of the primary brain injury and favour its recovery, and on the other hand, allow therapeutic resources to be individually adapted to the specific needs of the patient. Based on these notions, this article presents a decalogue of the physiological objectives to be achieved in brain injury, together with a series of diagnostic and therapeutic recommendations for achieving these goals. We emphasise the importance of considering and analysing the physiological variables involved in the transport of oxygen to the brain, such as cardiac output and arterial oxygen content, together with their conditioning factors and possible alterations. Special attention is paid to the basic elements of physiological neuroprotection, and we describe the multiple causes of cerebral hypoxia, how to approach them, and how to correct them. We also examine the increase in intracranial pressure as a physiopathological element, focussing on the significance of thoracic and abdominal pressure in the interpretation of intracranial pressure. Treatment of intracranial pressure should be based on a step-wise model, the first stage of which should be based on a physiopathological reflection combined with information on the tomographic lesions rather than on rigid numerical values.

Methane Saline Ameliorates Traumatic Brain Injury through Anti-Inflammatory, Antiapoptotic, and Antioxidative Effects by Activating the Wnt Signalling Pathway

Objective

Methane saline (MS) can be used to treat many diseases via its anti-inflammatory, antiapoptotic, and antioxidative activities. However, to date, there is no published evidence as to whether MS has any effect on traumatic brain injury (TBI). The Wnt signalling pathway regulates cell proliferation, differentiation, migration, and apoptosis; however, whether the Wnt signalling pathway regulates any effect of MS on TBI is unknown. This study was designed to explore the role of MS in the treatment of TBI and whether the Wnt pathway is involved.

Methods

Sprague-Dawley rats were randomly divided into five groups: sham, TBI, TBI+10 ml/kg MS, TBI+20 ml/kg MS, and TBI+30 ml/kg MS. After induction of TBI, MS was injected intraperitoneally once daily for seven consecutive days. Neurological function was evaluated by the Neurological Severity Score (NSS) at 1, 7, and 14 days after TBI. Haematoxylin-eosin (HE) staining, inflammatory factors, neuron-specific enolase (NSE) staining, oxidative stress, and cell apoptosis were measured and compared 14 d after TBI to identify the optimal dose of MS and to investigate the effect of MS on TBI. In the second experiment, Sprague-Dawley rats were randomly divided into four groups: sham, TBI, TBI+20 ml/kg MS, and TBI+20 ml/kg MS+Dickkopf-1 (DKK-1, a specific inhibitor of the Wnt pathway). NSE, caspase-3, superoxide dismutase (SOD), Wnt3a, and β-catenin were detected by real-time PCR and Western blotting. The results from each group were compared 14 d after TBI to determine the regulatory role of the Wnt pathway.

Results

Methane saline significantly inhibited inflammation, oxidative stress, and cell apoptosis, thus protecting neurons within 14 days of TBI. The best treatment effect against TBI was obtained with 20 ml/kg MS. When the Wnt pathway was inhibited, the treatment effect of MS was impaired.

Conclusion

Methane saline ameliorates TBI through its anti-inflammatory, antiapoptotic, and antioxidative effects via activation of the Wnt signalling pathway, which plays a part but is not the only mechanism underlying the effects of MS. Thus, MS may be a novel strategy for treating TBI.

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.

Effectiveness of Pharmacological Agents and Validation of Diagnostic Scales for the Management of Paroxysmal Sympathetic Hyperactivity in Hispanics

The identification and treatment of paroxysmal sympathetic hyperactivity (PSH) still present a significant challenge. We assessed the efficacy of pharmacological agents in treating PSH symptoms and the validity of the diagnostic scales in a cohort of Hispanic patients. A retrospective chart review of cases from a single hospital was conducted in 464 records. Exclusion criteria included underlying conditions such as severe infection. Only nine patients remained in the cohort after examining their clinical records, corresponding to the following diagnoses: traumatic brain injury, subdural hemorrhage, anoxic or ischemic encephalopathy, pneumocephalus, and cerebral palsy. Using the PSH likelihood scale, six of the nine patients were identified with a score of 17 or higher, corresponding to a "probable" PSH, and three patients obtained a score between 8 and 16, corresponding to a "possible" PSH diagnosis. The top three classes of medications used were beta-blockers, antipyretics, and opioids. Benzodiazepines and neuromodulators were also frequently used in patients with trauma, but not in the ones with non-traumatic injuries. Interestingly, 75% of the patients have prescribed levothyroxine as a home medication after the PSH presentation. Medication administration did not follow a specific pattern, suggesting high variability in the management of PSH within our setting, requiring further research. Our results suggest that the pituitary axis might be involved in the progression of PSH. Establishing a specific medical code (e.g., ICD-10) describing PSH as a single entity is essential for appropriate identification and management.

Evidence Limitations in Determining Sexually Dimorphic Outcomes in Pediatric Post-Traumatic Hypopituitarism and the Path Forward

Neuroendocrine dysfunction can occur as a consequence of traumatic brain injury (TBI), and disruptions to the hypothalamic-pituitary axis can be especially consequential to children. The purpose of our review is to summarize current literature relevant to studying sex differences in pediatric post-traumatic hypopituitarism (PTHP). Our understanding of incidence, time course, and impact is constrained by studies which are primarily small, are disadvantaged by significant methodological challenges, and have investigated limited temporal windows. Because hormonal changes underpin the basis of growth and development, the timing of injury and PTHP testing with respect to pubertal stage gains particular importance. Reciprocal relationships among neuroendocrine function, TBI, adverse childhood events, and physiological, psychological and cognitive sequelae are underconsidered influencers of sexually dimorphic outcomes. In light of the tremendous heterogeneity in this body of literature, we conclude with the common path upon which we must collectively arrive in order to make progress in understanding PTHP.

Diabetes exacerbates brain pathology following a focal blast brain injury: New role of a multimodal drug cerebrolysin and nanomedicine

Blast brain injury (bBI) is a combination of several forces of pressure, rotation, penetration of sharp objects and chemical exposure causing laceration, perforation and tissue losses in the brain. The bBI is quite prevalent in military personnel during combat operations. However, no suitable therapeutic strategies are available so far to minimize bBI pathology. Combat stress induces profound cardiovascular and endocrine dysfunction leading to psychosomatic disorders including diabetes mellitus (DM). This is still unclear whether brain pathology in bBI could exacerbate in DM. In present review influence of DM on pathophysiology of bBI is discussed based on our own investigations. In addition, treatment with cerebrolysin (a multimodal drug comprising neurotrophic factors and active peptide fragments) or H-290/51 (a chain-breaking antioxidant) using nanowired delivery of for superior neuroprotection on brain pathology in bBI in DM is explored. Our observations are the first to show that pathophysiology of bBI is exacerbated in DM and TiO₂-nanowired delivery of cerebrolysin induces profound neuroprotection in bBI in DM, not reported earlier. The clinical significance of our findings with regard to military medicine is discussed.

Sex as a Biological Variable in Preclinical Modeling of Blast-Related Traumatic Brain Injury

Approaches to furthering our understanding of the bioeffects, behavioral changes, and treatment options following exposure to blast are a worldwide priority. Of particular need is a more concerted effort to employ animal models to determine possible sex differences, which have been reported in the clinical literature. In this review, clinical and preclinical reports concerning blast injury effects are summarized in relation to sex as a biological variable (SABV). The review outlines approaches that explore the pertinent role of sex chromosomes and gonadal steroids for delineating sex as a biological independent variable. Next, underlying biological factors that need exploration for blast effects in light of SABV are outlined, including pituitary, autonomic, vascular, and inflammation factors that all have evidence as having important SABV relevance. A major second consideration for the study of SABV and preclinical blast effects is the notable lack of consistent model design—a wide range of devices have been employed with questionable relevance to real-life scenarios—as well as poor standardization for reporting of blast parameters. Hence, the review also provides current views regarding optimal design of shock tubes for approaching the problem of primary blast effects and sex differences and outlines a plan for the regularization of reporting. Standardization and clear description of blast parameters will provide greater comparability across models, as well as unify consensus for important sex difference bioeffects.

Is it prime time for sex and gender considerations in traumatic brain injury? Perspectives of rehabilitation care professionals

Purpose: The purpose of this study was to explore rehabilitation clinicians' understanding of how sex and gender facilitate or hinder care provided to patients with traumatic brain injury (TBI).Materials and methods: Sixteen clinicians from various specialities, attending to patients with TBI from a large rehabilitation hospital in Ontario, Canada, were recruited using purposive sampling. Data was collected through semi-structured interviews and thematic analysis was used to identify reoccurring themes.Results: Three themes that facilitate or hinder care of TBI patients were identified: (1) knowledge and evidence; (2) gender and other aspects of recovery; and (3) family caregiving. Lack of education about the topic and inconsistent scientific evidence limited clinicians' attention to sex and gender topics. Social, financial, and cultural characteristics of patients were considered to be more relevant than their sex and gender. The gendered nature of caregiving and its burden on caregivers' health were acknowledged.Conclusions: Currently, attention to topics of sex and gender as they may influence patients' recovery is limited. However, clinicians are willing to be educated on these topics to enhance rehabilitation care. Further research on the gendered nature of interactions between patient, clinician, and family caregiver during recovery is warranted.IMPLICATIONS FOR REHABILITATIONSex and gender matter for patients undergoing recovery for their traumatic brain injury; however, clinical attention to this topic is limited.Based on the clinicians' perceptions, resources that address patients' psychosocial vulnerabilities should be prioritized (e.g., unequal access to care, financial status, cultural diversity etc.).Clinicians highlighted that psychosocial vulnerability and patients' life roles, before and after injury, are sex and gender specific.Guidelines about sex and gender influences in traumatic brain injury rehabilitation have the potential to enhance clinical practice.

Impact of Pituitary Autoimmunity and Genetic Disorders on Growth Hormone Deficiency in Children and Adults

Growth hormone (GH), mostly through its peripheral mediator, the insulin-like growth factor 1(IGF1), in addition to carrying out its fundamental action to promote linear bone growth, plays an important role throughout life in the regulation of intermediate metabolism, trophism and function of various organs, especially the cardiovascular, muscular and skeletal systems. Therefore, if a prepubertal GH secretory deficiency (GHD) is responsible for short stature, then a deficiency in adulthood identifies a nosographic picture classified as adult GHD syndrome, which is characterized by heart, muscle, bone, metabolic and psychic abnormalities. A GHD may occur in patients with pituitary autoimmunity; moreover, GHD may also be one of the features of some genetic syndromes in association with other neurological, somatic and immune alterations. This review will discuss the impact of pituitary autoimmunity on GHD and the occurrence of GHD in the context of some genetic disorders. Moreover, we will discuss some genetic alterations that cause GH and IGF-1 insensitivity and the arguments in favor and against the influence of GH/IGF-1 on longevity and cancer in the light of the papers on these issues that so far appear in the literature.

Growth Hormone Deficiency Following Traumatic Brain Injury

Traumatic brain injury (TBI) is fairly common and annually affects millions of people worldwide. Post traumatic hypopituitarism (PTHP) has been increasingly recognized as an important and prevalent clinical entity. Growth hormone deficiency (GHD) is the most common pituitary hormone deficit in long-term survivors of TBI. The pathophysiology of GHD post TBI is thought to be multifactorial including primary and secondary mechanisms. An interplay of ischemia, cytotoxicity, and inflammation post TBI have been suggested, resulting in pituitary hormone deficits. Signs and symptoms of GHD can overlap with those of TBI and may delay rehabilitation/recovery if not recognized and treated. Screening for GHD is recommended in the chronic phase, at least six months to a year after TBI as GH may recover in those with GHD in the acute phase; conversely, it may manifest in those with a previously intact GH axis. Dynamic testing is the standard method to diagnose GHD in this population. GHD is associated with long-term poor medical outcomes. Treatment with recombinant human growth hormone (rhGH) seems to ameliorate some of these features. This review will discuss the frequency and pathophysiology of GHD post TBI, its clinical consequences, and the outcomes of treatment with GH replacement.