The influence of hypertensive environment on adipose tissue remodeling measured by fluorescence lifetime imaging in spontaneously hypertensive rats

There is a lack of information correlating low adiposity with hypertension experienced by Spontaneous Hypertensive Rats (SHR) or overweight and normotension in Wistar-Kyoto (WKY). We aimed to investigate this lipodystrophy phenomenon by measuring fluorescence lifetime (FLIM), optical redox ratio (ORR), serum levels of hypothalamic-pituitary-adrenal (HPA) and/or hypothalamic-pituitary-thyroid (HPT) hormones axes between Wistar, WKY and SHR before and after establishment of hypertension. Under high blood pressure, we evaluated serum adipokines. Brown adipose tissue was characterized as lower ORR and shorter FLIM compared to white adipose tissue. HPT axis showed a crucial role in the SHR adipose tissue configuration by attenuating whitening. The increased adiposity in WKY may act as a preventive agent for hypertension, since SHR, with low adiposity, establishes the disease. The hypertensive environment can highlight key adipokines that may result in new therapeutic approaches to the treatment of adiposity dysfunctions and hypertension.

Functional gastrointestinal disorders and gut-brain axis: What does the future hold?

Despite their high prevalence, lack of understanding of the exact pathophysiology of the functional gastrointestinal disorders has restricted us to symptomatic diagnostic tools and therapies. Complex mechanisms underlying the disturbances in the bidirectional communication between the gastrointestinal tract and the brain have a vital role in the pathogenesis and are key to our understanding of the disease phenomenon. Although we have come a long way in our understanding of these complex disorders with the help of studies on animals especially rodents, there need to be more studies in humans, especially to identify the therapeutic targets. This review study looks at the anatomical features of the gut-brain axis in order to discuss the different factors and underlying molecular mechanisms that may have a role in the pathogenesis of functional gastrointestinal disorders. These molecules and their receptors can be targeted in future for further studies and possible therapeutic interventions. The article also discusses the potential role of artificial intelligence and machine learning and its possible role in our understanding of these scientifically challenging disorders.

Prediction of pituitary stalk position in pituitary adenomas by visualization of the hypothalamo-hypophyseal tract using diffusion tensor imaging tractography

The preservation of pituitary stalk during surgery is very important for neurosurgeons. Sometimes, it is hard to identify the pituitary stalk in the operation. The hypothalamo-hypophyseal tract (HHT) projects through the pituitary stalk to the posterior pituitary gland. If the HHT can be identified, the position of pituitary stalk will be visualized. The diffusion tensor imaging (DTI) fiber tracking technique has been widely used for the quantitative assessment of the white matter integrity and thus may be suitable for the evaluation of the HHT.DTI was used to track the HHT in 11 patients with pituitary adenoma, and the location of the tract was compared with the pituitary stalk of postoperative image in those patients.The fiber tracking and 3D visualization of the HHT were successfully carried out in all 11 patients. Comparison between the tract and pituitary stalk of postoperative magnetic resonance imaging (MRI) was carried out in 9 patients. The results revealed that the position of tract was consistent with the pituitary stalk of postoperative MRI image in 8 patients (88.9%). The properties of tract showed that the median number of tract was 5.18 ± 7.00, the median fractional anisotropy (FA) was 0.14 ± 0.04, and the median length was 28.81 ± 7.94 mm.HHT can be tracked and visualized with the DTI-FT technique. It will be helpful to identify the location of pituitary stalk preoperatively.

A study of neuroendocrine dysfunction in patients of tuberculous meningitis

BACKGROUND

Endocrine dysfunction is known to occur in various infectious diseases of the brain. The neuroendocrine dysfunction is not well studied in patients of Tuberculous meningitis (TBM). In this study, we aimed at knowing pattern of endocrine dysfunction in newly diagnosed patients of tuberculous meningitis, structural changes occurring in hypothalamic-pituitary region, assessing its predictors and correlative factors related to outcome.

MATERIALS AND METHODS

This was a prospective observational study. All newly diagnosed patients of tuberculous meningitis were subjected to clinical, laboratory, and hormonal evaluation along with neuroimaging of hypothalamic-pituitary region. All the patients were treated with antituberculous drugs along with corticosteroids as per WHO guidelines. The clinical outcomes of the patients were assessed at the end of 3months.

RESULTS

Out of 115 patients enrolled in the study, endocrine dysfunction was seen in 62 (53.9%) patients. Out of these 62 patients, single axis involvement was seen in 35 (30.4%) patients, while multiple axis dysfunction was observed in 27 (23.5%) patients. Most common hormonal axis involved was gonadotropic axis (33.9%) followed by hyperprolactinemia (22.6%), thyrotropic axis (17.4%), corticotropic axis (13%), SIADH (Syndrome of Inappropriate Antidiuretic Hormone secretion) (9.6%) and somatotropic axis (7.8%). None had diabetes insipidus. The presence of multiple cranial nerve palsies, hypotension, stage II and III of TBM, baseline MBI ≤12 and basal exudates were significantly higher in endocrine dysfunction group, while the presence of basal exudates independently predicted the occurrence of endocrine dysfunction on multivariate analysis. Though the poor outcome was significantly higher in endocrine dysfunction group at the end of 3months, on multivariate analysis factors independently associated with poor outcome were the presence of altered sensorium and stage III of TBM.

CONCLUSION

Endocrine dysfunction occurs in a significant proportion of patients with tuberculous meningitis. The presence of basal exudates is significantly associated with the occurrence of endocrine dysfunction. Patients with endocrine dysfunction had a poorer outcome although it was not an independent predictor of the same nor associated with increased mortality.

Severe hypothalamopituitary dysfunction accompanied by influenza-associated encephalopathy: report of two pediatric cases

Severe influenza infection may lead to neurological damage, such as encephalopathy. This may, in turn, cause acquired hypothalamopituitary dysfunction, which can result in severe morbidity and even death. We herein report two pediatric patients who developed influenza-associated hypopituitarism and were subsequently diagnosed with encephalopathy. They were diagnosed with acute necrotizing encephalopathy and postresuscitation encephalopathy, respectively. Both showed evidence of endocrine dysfunction, and hormone replacement therapy of adrenal, thyroid, and antidiuretic hormones are resulting in continued cardiac activity and resulted in prolonged survival. Screening for endocrine function is important in patients with severe central nervous system dysfunction.

Endocrine manifestations in Langerhans cell histiocytosis

Langerhans cell histiocytosis is a rare, multisystem disease that shows a particular predilection for hypothalamo-pituitary axis involvement. Diabetes insipidus is the most frequent permanent consequence of Langerhans cell histiocytosis, developing in around a quarter of patients. Although the exact prevalence of anterior pituitary hormone deficiencies is not known, it is probably high and is almost always associated with diabetes insipidus. Established pituitary hormone deficiencies are mostly permanent and require prompt diagnosis and treatment, whereas continuous follow-up is needed to detect deficiencies that might evolve later during the course of the disease. Involvement of endocrine tissues other than the pituitary has also been described but is relatively rare. Further studies are needed to evaluate the effect that endocrine deficiencies exert on the overall prognosis of patients with Langerhans cell histiocytosis.

Paralimbic and medial prefrontal cortical involvement in neuroendocrine responses to traumatic stimuli

OBJECTIVE

Hypothalamic-pituitary-adrenal axis activity and cortisol release are consequences of central stress system activation, but they may also influence cognitive and emotional processes within the brain. Despite the importance of central stress response systems, little is known about the specific brain circuits through which psychosocial stimuli activate the hypothalamic-pituitary-adrenal axis and through which cortisol feedback modulates central processing. The authors used [(15)O]H(2)O positron emission tomography (PET) on subjects with posttraumatic stress disorder (PTSD) to study these circuits.

METHOD

Participants were combat-PTSD patients, combat-exposed healthy comparison subjects, and noncombat-exposed healthy comparison subjects. Participants were scanned using [(15)O]H(2)O PET while they experienced a series of emotional-induction conditions, which included aversive pictures and autobiographic narratives. Blood samples were obtained 2 minutes before and 5 minutes after each activation scan in order to measure the subjects' plasma adrenocorticotropic hormone and cortisol levels.

RESULTS

In voxel-wise analyses, the authors found that adrenocorticotropic hormone responses were covaried with regional cerebral blood flow (rCBF) in the dorsal medial prefrontal cortex, rostral anterior cingulate cortex, and right insula, with some differences between PTSD patients and comparison subjects. Prestimulus cortisol levels covaried with rCBF responses in the rostral anterior cingulate cortex. In combat-PTSD patients only, prestimulus cortisol levels covaried with rCBF in the subgenual anterior cingulate cortex.

CONCLUSIONS

These findings provide evidence of cortical involvement in hypothalamic-pituitary-adrenal responses to psychological stimuli, specifically implicating the insula, dorsal medial prefrontal cortex, and rostral anterior cingulate cortex. These findings also show, for the first time, that cortisol may modulate activity in specific brain areas such as the rostral and subgenual anterior cingulate cortices. Differential patterns of covariation between combat veterans with and without PTSD potentially implicate the dorsal medial prefrontal cortex and subgenual anterior cingulate cortex as areas of dysregulation in PTSD.

[Hyperprolactinemia: causes, diagnosis, and treatment]

The basic data on hyperprolactinemia (i.e. an excess of PRL above a reference laboratory's upper limits), the most common endocrine disorder of the hypothalamic-pituitary axis are given in this review. The following issues are discussed: regulation of prolactin (Prl) secretion, definition of hyperprolactinemia, its etiology and pathogenesis as well as its symptoms, diagnosis, and treatment (including medical and surgical therapy). It should be stressed that finding of elevated PRL serum concentrations constitute the beginning of diagnostic procedure and, after exclusion of physiologic, pharmacologic, and other organic causes of increased PRL levels, should be followed by detailed diagnosis including MRI. In patients in whom hyperprolactinemia has been confirmed the treatment with dopamine agonists (with prevalence of cabergoline, followed by quinagoline) is currently considered first-choice therapy. Surgery should be performed only in the patients resistant or intolerant to these agents, or in patients who refuse long-term therapy.

Alternatives to growth hormone stimulation testing in children

Despite more than 40 years of pediatric growth hormone (GH) replacement, we are still limited in our ability to make a definitive diagnosis of GH deficiency (GHD) in children. Historically, GH stimulation tests (GHSTs) have been used to discriminate between GHD and idiopathic short stature. Over the years, increases in the peak diagnostic GH cutoffs and the proliferation of GH assays have fundamentally changed the nature of the GHST. In our opinion, today's GHSTs lack reproducibility and accuracy, are expensive, and can be dangerous. Moreover, newer diagnostic tools, such as high-resolution neuroimaging, measurements of serum insulin-like growth factor 1 and insulin-like growth factor-binding protein 3, and an increasing number of genetic tests, have emerged. We believe that it is no longer appropriate to use GHSTs to diagnose childhood GHD. Instead, diagnosis should be based on a combination of auxological, biochemical, neuroradiological and genetic considerations. Here, we examine the alternatives to the GHST that are currently available and literature that supports their use. We believe that these alternative methods should replace the GHST.

[Neuroradiological investigation in patients with idiopathic growth hormone deficiency]

OBJECTIVE

The aim of this study was to analyze the type and frequency of cranial computed tomography and magnetic resonance imaging anomalies in patients with idiopathic growth hormone deficiency, and also to investigate the possible relationship between neuroradiological images and the presence of isolated growth hormone or multiple pituitary hormone deficiency.

METHODS

Magnetic resonance and computed tomography images were obtained for 37 patients with idiopathic growth hormone deficiency. The patients were divided into two groups: patients with isolated growth hormone (group A) and patients with multiple pituitary hormone deficiencies (group B).

RESULTS

Computed tomography was normal in 25 (68%), and abnormal in 12 (32%) patients. We observed empty sella in 50%, partially empty sella in 17% and anterior pituitary hypoplasia in 33% patients. MRI studies revealed normal findings in the hypothalamus-pituitary area in 17 (46%) and abnormal in 20 (54%) patients. We did not observed differences in the frequency of computed tomography alterations when groups A and B were compared (p = 0.55). With magnetic resonance imaging we observed, empty sella in 10%, partially empty sella in 15% and anterior pituitary hypoplasia in 75% patients. Among those patients whose magnetic resonance images were altered, the posterior lobe of the pituitary gland was identified in an abnormal position in 70%, and the hypophyseal stalk was thin or interrupted in 60%. The patients from group B presented a higher frequency of magnetic resonance imaging anomalies (90%) when compared to group A (10%), p = 0.03. There was disagreement between the two methods in 43% of cases, but we didn't observe a difference in the frequency of alterations when computed tomography was compared with magnetic resonance imaging (p = 0.06).

CONCLUSIONS

The most frequent defects observed using magnetic resonance imaging are anterior pituitary hypoplasia and ectopic posterior pituitary lobe. The association of glandular hypoplasia with other magnetic resonance imaging abnormalities can suggest the presence of multiple anterior pituitary deficiencies.

Reversible MRI changes of hypothalamus in a multiple sclerosis patient with homeostatic disturbances

Multiple sclerosis (MS) patients occasionally present with homeostatic disturbances suggestive of hypothalamic dysfunction; however, the hypothalamus often appears normal on imaging, apart from confirmation in a few necropsy studies. In this article we describe a Chinese woman with atypical clinical presentation. She presented with relapsing symptoms and signs consistent with hypothalamic dysfunction including hyperprolactinema, syndrome of inappropriate secretion of anti-diuretic hormone (SIADH), hypersomnolence and temperature dysregulation. Serial MRI depicted the atypical reversible changes in the hypothalamus, correlating with the observed homeostatic abnormalities.

[Assessment of endocrine disorders of the hypothalamic-pituitary axis by nuclear medicine techniques]

The following article reviews nuclear medicine techniques which can be used for assessment of endocrine disorders of the hypothalamic-pituitary axis. For planar and SPECT imaging somatostatin-receptor- and dopamine-D2-receptor-scintigraphy are the most widely distributed techniques. These nuclear medicine techniques may be indicated in selected cases to answer differential diagnostic problems. They can be helpful to search for presence and localization of receptor positive tissue. Furthermore they can detect metastasis in the rare cases of a pituitary carcinoma. Scintigraphy with Gallium-67 is suitable for further diagnostic evaluation in suspected hypophysitis. Other SPECT radiopharmaca do not have relevant clinical significance. F-18-FDG as PET radiopharmacon is not ideal because obvious pituitary adenomas could not be visualized. Other PET radiopharmaca including C-11-methionine, C-11-tyrosine, F-18-fluoroethylspiperone, C-11-methylspiperone, and C-11-raclopride are available in specialized centers only. Overall indications for nuclear medicine in studies for the assessment of endocrine disorders of the hypothalamic-pituitary-axis are rare. Original studies often report only about a small number of patients. According to the authors' opinion the relevance of nuclear medicine in studies of clinically important endocrinologic fields, e.g. localization of small ACTH-producing pituitary adenomas, tumor localization in ectopic ACTH syndrome, localization of recurrent pituitary tissue, assessment of small incidentalomas, can not be definitely given yet.

Long-term follow-up evaluation of magnetic resonance imaging in the prognosis of permanent GH deficiency

OBJECTIVE

In patients with GH deficiency (GHD), magnetic resonance imaging (MRI) has revealed morphological abnormalities such as pituitary hypoplasia, pituitary stalk agenesis (PSA) and ectopia of the posterior pituitary (PPE). The MRI anomalies have been more frequently reported in patients with multiple pituitary hormone deficiency (MPHD) than in subjects with isolated GH deficiency (IGHD). The aim of this work was to define which MRI anatomical abnormalities of the hypothalamo-pituitary area can be considered as a prognostic marker of permanent GHD.

DESIGN

To investigate the relationship between the neuroradiological images and endocrine findings, we clinically re-evaluated 93 out of the 121 GHD patients with IGHD and MPHD previously studied.

RESULTS

No additional hormone deficiencies were observed in 55 out of 60 patients initially classified as having IGHD with a normal (15 cases) or reduced (40 cases) pituitary gland size, without other MRI abnormalities. The remaining five children, who had initially shown an apparently IGHD in spite of PSA and PPE, developed a MPHD over time. In 33 MPHD patients with (25 cases) or without (8 cases) MRI abnormalities, the associated hormone deficiencies were confirmed during follow-up.

CONCLUSIONS

The IGHD patients showing PSA and PPE inevitably develop additional hormone deficiencies, while IGHD subjects having no MRI abnormalities maintain IGHD. Moreover, the anatomical abnormalities of the hypothalamo-pituitary area can be considered as a prognostic marker of permanent GHD.

Psychoneuroendocrinology and brain imaging in depression

In the past three decades, psychoneuroendocrinologic investigations have generated a great volume of information, particularly in the field of affective disorders, which has formed the basis for designing studies with newer tools such as anatomic and functional imaging. In this article, the authors focus on endocrine imaging in psychiatry and attempt to relate morphometric findings to physiologic neuroendocrine dysfunction in depression.

Changes of sympatho-adrenal and hypothalamo-pituitary-adrenocortical system in patients with head injury

To determine the role of the sympatho-adrenal (SAS) and hypothalamo-pituitary-adrenocortical system (HPAS) after head injury, the relationship between venous blood epinephrine (E), norepinephrine (NE), adrenocorticotropic hormone (ACTH), cortisol levels, and clinical condition was examined in 55 patients. These observations suggest that head injury causes mainly activation of the above-mentioned systems depending on the severity of trauma. An inverse correlation between the levels of E, NE and Glasgow Coma Scale score, indicating the severity of head injury was revealed. ACTH and cortisol were similarly related to the clinical condition, although the observed correlation was less expressed. The changes in hormonal levels were present during the whole research period (1 week), although a certain shift to normalization was observed. However, catecholamines and ACTH levels in plasma were relatively low in severely head-injured patients whose CT scans revealed serious alterations in the mesencephalic-diencephalic area. At the same time their cortisol levels obtained maximal values and their chance to survive was diminutive. The results of this study indicate that investigation of hormones of SAS and HPAS might be useful as an additional method in the complex of ordinary examinations in establishing early prognosis in patients with brain injury.

Ictal laughter associated with paroxysmal hypothalamopituitary dysfunction

PURPOSE

Seizures with ictal laughter (also termed gelastic seizures) have been associated with hypothalamic hamartomas and precocious puberty. It is not known, however, where in the brain such seizures originate. We describe a child with gelastic seizures and a hypothalamic lesion (probably a hamartoma) in whom two dysfunctional phenomena were observed.

RESULTS

First, there was a hyperperfusion in the hypothalamopituitary areas shown by ictal [99m]Tc hexamethyl-propyleneamine oxime (HM-PAO) single photon-emission computed tomography (SPECT). Second, there was an ictal pulse of gonadotropins, 17 beta-estradiol, and growth hormone well above the normal limits in one of the seizures.

CONCLUSION

These findings suggest that gelastic seizures associated with hypothalamic hamartomas are generated in the hypothalamus or in its neighboring regions and that these seizures may cause paroxysmal dysfunction of the hypothalamopituitary axis.

Adrenocortical insufficiency

Adrenocortical insufficiency causes difficulty in diagnosis and morbidity out of proportion to its rarity, because of the non-specific, multi-system nature of the clinical features. Most of these are due to cortisol deficiency. Prominent features are well-known ones such as weight loss and asthenia, and hypoglycaemia. Less prominent in recent accounts are those due to failure of cellular sodium export and to vasopressin excess, which are frequent and clinically significant. For this reason, the clinical features of isolated ACTH deficiency, isolated glucocorticoid deficiency and Addison's disease overlap greatly. In addition, cortisol deficiency has secondary endocrine effects, e.g. glucocorticoid-reversible hypothyroidism, hyperprolactinaemia and hypercalcaemia. Further overlap between the various steroid insufficiency syndromes occurs because of the association of various organ-specific autoimmune endocrinopathies with Addison's disease. Over 80% of Addison's disease is of the autoimmune type, though almost any systemic destructive process can cause similar steroid insufficiency. Demonstration of adrenal insufficiency requires various combinations of tetracosactrin adrenal stimulation tests, and hypoglycaemia or equivalent tests, if the cause is ACTH deficiency but the correct test can only be chosen to suit a firm clinical diagnosis. The treatment of adrenocortical insufficiency is described.

Empty sella turcica in intracranial sarcoidosis. Pituitary insufficiency, primary polydipsia, and changing neuroradiologic findings

A 37-year-old man with visual loss was found to have hypopituitarism and primary polydipsia associated with sarcoidosis. Neuroradiologic studies demonstrated a dramatic evolution of CNS lesions, including a left thalamic infarct, an enhancing suprasellar mass, and ultimately an empty sella turcica. The patient has been clinically stable in spite of these changes. This case is likely to be the first reported of CNS sarcoidosis with an empty sella turcica documented by computed tomography.

Current approaches to hypothalamic-pituitary radiology

Currently computed tomography (CT) is the primary imaging modality for pituitary and hypothalamic lesions, although it is probable that NMR will supersede it. The range of size of the normal pituitary is considerable, with relatively larger glands occurring in adolescence and females of childbearing age. Asymptomatic microadenomas and cysts are not infrequent so that small low-density lesions in a gland on the borderline of enlargement can only be assessed in relation to clinical presentation. Patients presenting with clinical or biochemical evidence of abnormal pituitary hormone secretion or with an enlarged sella but without evidence of any neurological abnormality are likely to have either a small pituitary tumour or an empty sella and are investigated by thin section high resolution CT to produce coronal and sagittal images. Visual defects, paralysis of ocular muscles or hypothalamic disturbances, in the absence of clinical evidence of hypersecretion of pituitary hormones, may be due to a variety of pathologies. These cases are elucidated by plain plus contrast-enhanced CT, supplemented as necessary by angiography and computed cysternography after injection of non-ionic contrast media. Hypothalamic disturbances may occasionally complicate cerebral malformations which are also elucidated by cranial CT.

Computed tomography in diabetes insipidus

Thirteen patients aged 1 to 59 years hospitalized for diabetes insipidus (DI) were investigated by computed tomography (CT). Apart from one craniopharyngioma, CT revealed in 8 out of 12 cases several modifications in the hypothalamic-pituitary region. In this group, CT demonstrated a small, round, isodense mass in the chiasmatic cistern that enhanced after contrast medium injection. Coronal and sagittal reconstructions helped pinpoint the lesion in the infundibulum and pituitary stalk, and, in one case, in the supraoptic nuclei. These findings, and the noninvasiveness of CT, make this technique one of the most accurate means of radiological investigation of DI and also of determining the efficacy of therapy.