Current perspective on the pathogenesis of central diabetes insipidus

Central Diabetes Insipidus in Children as a Diagnostic Challenge

Central diabetes insipidus (CDI) is a disorder in the pediatric population resulting from antidiuretic hormone deficiency. The excessive production of dilute urine characterizes it and manifests with polyuria, nocturia, and polydipsia. The diagnostics of CDI is often challenging, especially concerning the underlying condition of the disease. This article highlights the diverse clinical presentation of children with CDI and diagnostic difficulties among patients with polyuria and polydipsia. The article also reviews the etiology, symptoms, diagnostic workup, and management of CDI. We present 4 pediatric patients (aged 3-13.5 years) diagnosed with CDI of different etiology: 1 due to septo-optic dysplasia/optic nerve hypoplasia and 3 due to acquired processes such as Langerhans cell histiocytosis and germ cell tumor in 2 patients. Central diabetes insipidus was the first manifestation of a tumor or granuloma in all presented patients with acquired pathology. The patients sometimes need long-term follow-up to establish the proper final diagnosis.

A Case of Central Diabetes Insipidus in a Patient With a Pineal Mass Suspected to Be a Germinoma: A Case Report

Central diabetes insipidus (CDI) is a rare condition characterized by excessive urination and thirst due to vasopressin deficiency. The underlying cause of CDI remains unknown in many cases. Tumors are a leading cause of CDI in young individuals, with germinoma being the most prevalent. We present a case of a 22-year-old male diagnosed with infundibuloneurohypophysitis (INH) of unknown etiology. His pituitary stalk thickening partially responded to high-dose prednisone treatment; however, one year after initial diagnosis, a new pineal region mass was noted on imaging. Further evaluation revealed the mass to be most likely a germinoma. This case emphasizes the importance of ongoing clinical and radiologic follow-up in idiopathic cases of CDI. The patient's symptoms improved with desmopressin, but the presence of the pineal mass necessitates further comprehensive neurosurgical evaluation.

Central diabetes insipidus in children: Diagnosis and management

Central diabetes insipidus (CDI) is a complex disorder in which large volumes of dilute urine are excreted due to arginine-vasopressin deficiency, and it is caused by a variety of conditions (genetic, congenital, inflammatory, neoplastic, traumatic) that arise mainly from the hypothalamus. The differential diagnosis between diseases presenting with polyuria and polydipsia is challenging and requires a detailed medical history, physical examination, biochemical approach, imaging studies and, in some cases, histological confirmation. Magnetic resonance imaging is the gold standard method for evaluating the sellar-suprasellar region in CDI. Pituitary stalk size at presentation is variable and can change over time, depending on the underlying condition, and other brain areas or other organs - in specific diseases - may become involved during follow up. An early diagnosis and treatment are preferable in order to avoid central nervous system damage and the risk of dissemination of germ cell tumor, or progression of Langerhans Cell Histiocytosis, and in order to start treatment of additional pituitary defects without further delay. This review focuses on current diagnostic work-up and on the role of neuroimaging in the differential diagnosis of CDI in children and adolescents. It provides an update on the best approach for diagnosis - including novel biochemical markers such as copeptin - treatment and follow up of children and adolescents with CDI; it also describes the best approach to challenging situations such as post-surgical patients, adipsic patients, patients undergoing chemotherapy and/or in critical care.

Causes and Follow-Up of Central Diabetes Insipidus in Children

OBJECTIVE

To identify the causes of central diabetes insipidus (CDI) by evaluating the values of magnetic resonance imaging (MRI) in the diagnosis of pediatric CDI, providing evidence for the clinical diagnosis and treatment of CDI.

METHODS

Seventy-nine patients with CDI (CDI group) hospitalized from July 2012 to March 2017 and 43 healthy children (control group) were enrolled in this study. All cases underwent MRI examination including T1-weighted three-dimensional magnetization-prepared rapid gradient-echo (T1WI-3D-MP RAGE) imaging sequences. The pituitary volume, the signal intensity of posterior pituitary, and the morphology of pituitary stalk were measured between two groups. The medical history, urine testing, imaging of hypothalamic-pituitary region, and hormone levels were also recorded.

RESULTS

Age and gender were matched between the CDI and control groups. The height and BMI in the CDI group were less and the urine volume in 24 h was higher than those in the control group. The signal intensity of the posterior pituitary was higher in the control group, whereas the pituitary volume was smaller in the CDI group. In the CDI group, 44 cases presented with morphological changes of the pituitary stalk. Clinical symptoms mainly included polydipsia, polyuria, short stature, and vomiting. All patients were confirmed by water deprivation vasopressin test. Forty-four CDI children were associated with hypopituitarism, including 33 cases of PSIS with multiple pituitary hormone deficiencies (MPHD) and 11 cases of growth hormone deficiency (IGHD). The pituitary volume in the cases of pituitary stalk interruption syndrome (PSIS) with MPHD was smaller than that in the IGHD patients.

CONCLUSIONS

The signal intensity ratio of the posterior lobe, pituitary volume, and the morphology of pituitary stalk on T1WI-3D-MP RAGE image contribute to the diagnosis of CDI.

Physiogenomics in Etiopathogenesis of Cholangiocarcinoma

Objective

Cholangiocarcinoma is a serious malignancy that is very common in the tropical countries. It is a kind of deadly primary hepatobiliary tumor. There is a wide spectrum of tumors with varying differentiation and malignancy grades. Although it has been known for a long time inmmedicine, there is no clear cut that this deadly cancer is genetic disorder or not. A systemic approach on the pathophysiology and genomics can provide useful information and help better understand the pathogenesis of cholangiocarcinoma.

Methods

In this work, a standard bioinformatics physiological genomics analysis of cholangiocarcinoma was performed.

Result

According to this work, there is no identified physiogenomics relationship for the cholangiocarcinoma.

Conclusion

This might imply that the cholangiocarcinoma is directly due to environmental insult. It implies that there should be no specific gene that might contribute to the increased risk in the etiopathogenesis of cholangiocarcinoma.

Management of diabetes insipidus and adipsia in the child

Central diabetes insipidus (CDI) is a complex and heterogeneous clinical syndrome affecting the hypothalamic-neurohypophyseal network and water balance. A recent national surveillance in Denmark showed a prevalence rate of twenty-three CDI patients per 100,000 inhabitants in five years. The differential diagnosis between several presenting conditions with polyuria and polydipsia is puzzling, and the etiological diagnosis of CDI remains a challenge before the identification of an underlying cause. For clinical practice, a timely diagnosis for initiating specific treatment in order to avoid central nervous system damage, additional pituitary defects and the risk of dissemination of germ cell tumor is advisable. Proper etiological diagnosis can be achieved via a series of steps that start with careful clinical observation of several signs and endocrine symptoms and then progress to more sophisticated imaging tools. This review summarizes the best practice and approach for the diagnosis and treatment of patients with CDI.

Natural history of idiopathic diabetes insipidus

OBJECTIVE

To determine what percentage of diabetes insipidus (DI) in childhood is idiopathic and to assess the natural history of idiopathic DI.

STUDY DESIGN

We conducted a retrospective chart review of 105 patients with DI who were born or had DI diagnosed between 1980-1989 at 3 medical centers. A second cohort of 30 patients from 6 medical centers in whom idiopathic DI was diagnosed after 1990 was evaluated retrospectively for subsequent etiologic diagnoses and additional hypothalamic/pituitary deficiencies and prospectively for quality of life.

RESULTS

In the first cohort, 11% of patients had idiopathic DI. In the second cohort, additional hypothalamic/pituitary hormone deficiencies developed in 33%, and 37% received an etiologic diagnosis for DI. Health-related quality of life for all the patients with idiopathic DI was comparable with the healthy reference population.

CONCLUSIONS

Only a small percentage of patients with DI will remain idiopathic after first examination. Other hormone deficiencies will develop later in one-third of those patients, and slightly more than one-third of those patients will have an etiology for the DI diagnosed. Long-term surveillance is important because tumors have been diagnosed as long as 21 years after the onset of DI. Quality of life for these patients is as good as the reference population.

Management of diabetes insipidus in children

Diabetes Insipidus (DI) is a heterogeneous clinical syndrome of disturbance in water balance, characterized by polyuria (urine output > 4 ml/kg/hr), polydypsia (water intake > 2 L/m(2)/d) and failure to thrive. In children, Nephrogenic DI (NDI) is more common than Central DI (CDI), and is often acquired. The signs and symptoms vary with etiology, age at presentation and mode of onset. Neonates and infants with NDI are severely affected and difficult to treat. Diagnosis is based on the presence of high plasma osmolality and low urinary osmolality with significant water diuresis. Water deprivation test with vasopressin challenge, though has limitations, is done to differentiate NDI and CDI and diagnose their partial forms. Measurement of urinary aquaporin 2 and serum copeptin levels are being studied and show promising diagnostic potential. Magnetic Resonance Imaging (MRI) pituitary helps in the etiological diagnosis of CDI, absence of posterior pituitary bright signal being the pathognomic sign. If pituitary stalk thickening of < 2 mm is present, these children need to be monitored for evolving lesion. Neonates and young infants are better managed with fluids alone. Older children with CDI are treated with desmopressin. The oral form is safe, highly effective, with more flexibility of dosing and has largely replaced the intranasal form. In NDI besides treatment of the underlying cause, use of high calorie low solute diet and drugs to ameliorate water excretion (thiazide, amelioride, indomethacin) are useful. Children with NDI however well treated, remain short and have mental retardation on follow up.

Efeitos endócrinos e metabólicos das drogas antiepilépticas

As drogas antiepilépticas (DAE) são utilizadas por um enorme contingente de pessoas em todo o mundo - tanto no tratamento das epilepsias como para outros fins - frequentemente por um longo tempo. Por essas razões, torna-se fundamental o conhecimento sobre os potenciais efeitos adversos desses medicamentos, muitos deles envolvendo vários aspectos hormonais e metabólicos que devem ser do conhecimento do endocrinologista. Nesta revisão, foi abordada a relação das DAE com anormalidades no metabolismo mineral ósseo, balanço energético e peso corporal, eixo gonadal e função tireoideana, além de ter sido revisado o papel terapêutico dessas medicações no tratamento da neuropatia diabética.

Permanent central diabetes insipidus with complete regression of pituitary stalk enlargement after 4 years of follow-up

A 14 year-old patient was admitted because of a history of polyuria and polydipsia. A diagnosis of central diabetes insipidus (CDI) accompanied by growth hormone (GH) and gonadotropin deficiency was made. Hypophyseal magnetic resonance imaging (MRI) of the patient demonstrated isolated pituitary stalk enlargement. Although GH deficiency and gonadotropin deficiency were transient, CDI was persistent despite the regression of the pituitary stalk enlargement over the 4 years of follow-up.

The vasopressin system--from antidiuresis to psychopathology

Vasopressin is a neuropeptide with multiple functions. In addition to its predominantly antidiuretic action after peripheral secretion from the posterior pituitary, it seems to fulfill--together with its receptor subtype--all requirements for a neuropeptide system critically involved in higher brain functions, including cognitive abilities and emotionality. Following somatodendritic and axonal release in distinct brain areas, vasopressin acts as a neuromodulator and neurotransmitter in multiple and varying modes of interneuronal communication. Accordingly, changes in vasopressin expression and release patterns may have wide-spread consequences. As shown in mice, rats, voles, and humans, central vasopressin release along a continuum may be beneficial to the individual, serving to adjust physiology and behavior in stressful scenarios, possibly at the potential expense of increasing susceptibility to disease. Indeed, if over-expressed and over-released, it may contribute to hyper-anxiety and depression-like behaviors. A vasopressin deficit, in turn, may cause signs of both diabetes insipidus and total hypo-anxiety. The identification of genetic polymorphisms underlying these phenomena does not only explain individual variation in social memory and emotionality, but also help to characterize potential targets for therapeutic interventions. The capability of both responding to stressful stimuli and mediating genetic polymorphisms makes the vasopressin system a key mediator for converging (i.e., environmentally and genetically driven) behavioral regulation.

The diagnosis of children with central diabetes insipidus

Central diabetes insipidus is the end result of a number of different diseases that affect the hypothalamic-neurohypophyseal system. In many patients, especially children and young adults, it is caused by the destruction or degeneration of neurons that originate in the supraoptic and paraventricular nuclei of the hypothalamus. The known causes of these lesions include germinoma or craniopharyngioma; Langerhans cell histiocytosis; local inflammatory, autoimmune or vascular diseases; trauma resulting from surgery or an accident; sarcoidosis; metastases; and midline cerebral and cranial malformations. In rare cases, genetic defects in AVP synthesis that are inherited as autosomal dominant, autosomal recessive or X-linked recessive traits are the underlying cause. Accurate diagnostic differentiation is essential for both safe and effective disease management. Proper etiological diagnosis can be achieved via a series of steps that start with clinical observations and then progress, as needed, to more sophisticated methods. Indeed, magnetic resonance imaging (MRI) represents the examination method of choice for evaluating hypothalamic-pituitary-related endocrine diseases due to its ability to provide strongly-contrasted high-resolution multi-planar and spatial images. Specifically, MRI allows a detailed and precise anatomical study of the pituitary gland by differentiating between the anterior and posterior pituitary lobes. MRI identification of pituitary hyperintensity in the posterior part of the sella, now considered to be a clear marker of neurohypophyseal functional integrity, together with careful analysis of pituitary stalk shape and size, have provided the most striking recent findings contributing to the diagnosis and understanding of some forms of 'idiopathic' central diabetes insipidus.

Familial neurohypophyseal diabetes insipidus--an update

Although molecular research has contributed significantly to our knowledge of familial neurohypophyseal diabetes insipidus (FNDI) for more than a decade, the genetic background and the pathogenesis still is not understood fully. Here we provide a review of the genetic basis of FNDI, present recent progress in the understanding of the molecular mechanisms underlying its development, and survey diagnostic and treatment aspects. FNDI is, in 87 of 89 kindreds known, caused by mutations in the arginine vasopressin (AVP) gene, the pattern of which seems to be largely revealed as only few novel mutations have been identified in recent years. The mutation pattern, together with evidence from clinical, cellular, and animal studies, points toward a pathogenic cascade of events, initiated by protein misfolding, involving intracellular protein accumulation, and ending with degeneration of the AVP producing magnocellular neurons. Molecular research has also provided an important tool in the occasionally difficult differential diagnosis of DI and the opportunity to perform presymptomatic diagnosis. Although FNDI is treated readily with exogenous administration of deamino-D-arginine vasopressin (dDAVP), other treatment options such as gene therapy and enhancement of the endoplasmic reticulum protein quality control could become future treatment modalities.