Diabetes Insipidus after Traumatic Brain Injury

Urine osmolality assessment through the integration of urea hydrolysis and impedance measurement

We present the development and validation of an impedance-based urine osmometer for accurate and portable measurement of urine osmolality. The urine osmolality of a urine sample can be estimated by determining the concentrations of the conductive solutes and urea, which make up approximately 94% of the urine composition. Our method utilizes impedance measurements to determine the conductive solutes and urea after hydrolysis with urease enzyme. We built an impedance model using sodium chloride (NaCl) and urea at various known concentrations. In this work, we validated the accuracy of the impedance-based urine osmometer by developing a proof-of-concept first prototype and an integrated urine dipstick second prototype, where both prototypes exhibit an average accuracy of 95.5 ± 2.4% and 89.9 ± 9.1%, respectively in comparison to a clinical freezing point osmometer in the hospital laboratory. While the integrated dipstick design exhibited a slightly lower accuracy than the first prototype, it eliminated the need for pre-mixing or manual pipetting. Impedance calibration curves for conductive and non-conductive solutes consistently yielded results for NaCl but underscored challenges in achieving uniform urease enzyme coating on the dipstick. We also investigated the impact of storing urine at room temperature for 24 hours, demonstrating negligible differences in osmolality values. Overall, our impedance-based urine osmometer presents a promising tool for point-of-care urine osmolality measurements, addressing the demand for a portable, accurate, and user-friendly device with potential applications in clinical and home settings.

Traumatic brain injury inducing swift transition from syndrome of inappropriate antidiuretic hormone secretion to central diabetes insipidus: a case report

Heavy traumatic brain injury (TBI) may lead to the manifestation of either syndrome of inappropriate secretion of antidiuretic hormones (SIADH) or central diabetes insipidus (CDI). We present a case of TBI where SIADH transformed into CDI within a remarkably short timeframe. A previously healthy 4-yr-old boy was admitted to our hospital with hyponatremia and elevated urinary sodium level on the day following a traumatic head injury. Within 150 min after initiating SIADH treatment, a significant increase in urine volume and a decrease in urinary sodium levels were observed. Therefore, the treatment plan was modified to include desmopressin. By the 5th day of admission, the urine volume gradually stabilized and normalized without the need for further desmopressin treatment. Mild TBI can give rise to various conditions that may undergo rapid changes. Closely monitoring serum and urine electrolytes, along with urine volume, is imperative for the administration of appropriate and timely treatment.

Initial dysnatremia and clinical outcomes in pediatric traumatic brain injury: a multicenter observational study

PURPOSE

We aimed to investigate the association between initial dysnatremia (hyponatremia and hypernatremia) and in-hospital mortality, as well as between initial dysnatremia and functional outcomes, among children with traumatic brain injury (TBI).

METHOD

We performed a multicenter observational study among 26 pediatric intensive care units from January 2014 to August 2022. We recruited children with TBI under 18 years of age who presented to participating sites within 24 h of injury. We compared demographics and clinical characteristics between children with initial hyponatremia and eu-natremia and between those with initial hypernatremia and eu-natremia. We defined poor functional outcome as a discharge Pediatric Cerebral Performance Category (PCPC) score of moderate, severe disability, coma, and death, or an increase of at least 2 categories from baseline. We performed multivariable logistic regression for mortality and poor PCPC outcome.

RESULTS

Among 648 children, 84 (13.0%) and 42 (6.5%) presented with hyponatremia and hypernatremia, respectively. We observed fewer 14-day ventilation-free days between those with initial hyponatremia [7.0 (interquartile range (IQR) = 0.0-11.0)] and initial hypernatremia [0.0 (IQR = 0.0-10.0)], compared to eu-natremia [9.0 (IQR = 4.0-12.0); p = 0.006 and p < 0.001]. We observed fewer 14-day ICU-free days between those with initial hyponatremia [3.0 (IQR = 0.0-9.0)] and initial hypernatremia [0.0 (IQR = 0.0-3.0)], compared to eu-natremia [7.0 (IQR = 0.0-11.0); p = 0.006 and p < 0.001]. After adjusting for age, severity, and sex, presenting hyponatremia was associated with in-hospital mortality [adjusted odds ratio (aOR) = 2.47, 95% confidence interval (CI) = 1.31-4.66, p = 0.005] and poor outcome (aOR = 1.67, 95% CI = 1.01-2.76, p = 0.045). After adjustment, initial hypernatremia was associated with mortality (aOR = 5.91, 95% CI = 2.85-12.25, p < 0.001) and poor outcome (aOR = 3.00, 95% CI = 1.50-5.98, p = 0.002).

CONCLUSION

Among children with TBI, presenting dysnatremia was associated with in-hospital mortality and poor functional outcome, particularly hypernatremia. Future research should investigate longitudinal sodium measurements in pediatric TBI and their association with clinical outcomes.

Examining the current health of Gulf War veterans with the veterans affairs frailty index

Introduction

Gulf War Illness (GWI) is a chronic, multisymptom (e.g., fatigue, muscle/joint pain, memory and concentration difficulties) condition estimated to affect 25-32% of Gulf War (GW) veterans. Longitudinal studies suggest that few veterans with GWI have recovered over time and that deployed GW veterans may be at increased risks for age-related conditions.

Methods

We performed a retrospective cohort study to examine the current health status of 703 GW veterans who participated in research studies at the San Francisco VA Health Care System (SFVAHCS) between 2002 and 2018. We used the Veterans Affairs Frailty Index (VA-FI) as a proxy measure of current health and compared the VA-FIs of GW veterans to a group of randomly selected age- and sex-matched, non-GW veterans. We also examined GW veterans' VA-FIs as a function of different GWI case definitions and in relationship to deployment-related experiences and exposures.

Results

Compared to matched, non-GW veterans, GW veterans had lower VA-FIs (0.10 ± 0.10 vs. 0.12 ± 0.11, p < 0.01). However, the subset of GW veterans who met criteria for severe Chronic Multisymptom Illness (CMI) at the time of the SFVAHCS studies had the highest VA-FI (0.13 ± 0.10, p < 0.001). GW veterans who had Kansas GWI exclusionary conditions had higher VA-FI (0.12 ± 0.12, p < 0.05) than veterans who were Kansas GWI cases (0.08 ± 0.08) and controls (i.e., veterans with little or no symptoms, 0.04 ± 0.06) at the time of the SFVAHCS research studies. The VA-FI was positively correlated with several GW deployment-related exposures, including the frequency of wearing flea collars.

Discussion

Although GW veterans, as a group, were less frail than non-GW veterans, the subset of GW veterans who met criteria for severe CDC CMI and/or who had Kansas GWI exclusionary conditions at the time of the SFVAHCS research studies were frailest at index date. This suggests that many ongoing studies of GWI that use the Kansas GWI criteria may not be capturing the group of GW veterans who are most at risk for adverse chronic health outcomes.

Correlation of Pituitary Descent and Diabetes Insipidus After Transsphenoidal Pituitary Macroadenoma Resection

BACKGROUND

Endoscopic transsphenoidal surgery remains the technique of choice for resection of pituitary adenoma. Postoperative diabetes insipidus (DI) is most often transient and observed in 1.6% to 34% of patients, whereas permanent DI has been reported in 0% to 2.7% of patients. The proposed mechanism was the transduction of traction forces exerted by the surgeon on the descended diaphragma sellae and through the pituitary stalk.

OBJECTIVE

To quantify and correlate the degree of pituitary gland descent with postoperative DI.

METHODS

Of 374 patients who underwent transsphenoidal resection of a pituitary adenoma between 2010 and 2020 at our institution, we report a cohort of 30 patients (Group A) DI. We also report a matched cohort by tumor volume of 30 patients who did not develop DI (Group B). We quantified the tension on the pituitary stalk by calculating pituitary descent interval (PDI) by comparing preoperative and postoperative position of the pituitary gland and using Pythagoras' formula where , with craniocaudal (CC) and anterior-posterior (AP) representing measurements of pituitary translation in respective directions after resection.

RESULTS

Patients who developed DI had significantly greater pituitary gland translations in the craniocaudal (23.0 vs 16.3 mm, P = .0015) and anteroposterior (2.4 vs 1.5 mm, P = .0168) directions. Furthermore, Group A had a statistically greater PDI, which was associated with development of DI (23.2 vs 16.6 mm, P = .0017).

CONCLUSION

We were able to quantify pituitary descent and subsequent tension on the pituitary stalk, while also associating it with development of postoperative DI after pituitary adenoma resection.

Diabetes insipidus related to sedation in the intensive care unit: A review of the literature

PURPOSE

To identify cases of diabetes insipidus (DI) related to sedation in the ICU to determine which medications pose the greatest risk and understand patterns of presentation.

MATERIALS AND METHODS

We searched PubMed, Embase, Scopus, Google Scholar, and Web of Science. Search terms included "polyuria," "diabetes insipidus," "hypnotics and sedatives," "sedation," as well as individual medications. Case reports or series involving DI or polyuria related to sedation in the ICU were identified.

RESULTS

We identified 21 cases of diabetes insipidus or polyuria in the ICU attributed to a sedative. Dexmedetomidine was implicated in 42.9% of cases, followed by sevoflurane (33.3%) and ketamine (23.8%). Sevoflurane was implicated in all 7 cases in which it was used (100%; 95% CI 59.0%, 100.0%), dexmedetomidine in 9 of 11 cases (81.8%; 95% CI 48.2, 97.7), and ketamine in 5 of 9 cases (55.6%; 95% CI 21.2%, 86.3%).

CONCLUSIONS

Awareness of the potential for sedatives to cause DI may lead to greater identification with swifter medication discontinuation and subsequent resolution of DI.

Neuroendocrine Disruptions Following Head Injury

PURPOSE OF REVIEW

This article reviews hypopituitarism after TBI, the importance of pituitary hormones, and related controversies, concluding with a suggested patient approach.

RECENT FINDINGS

While earlier studies focused on increased pituitary deficiencies after moderate-severe TBI, recent studies have focused on deficiencies after mild TBI. There has been increasing focus on the role of growth hormone after injury; growth hormone is the most frequent reported deficiency at 1 year post-TBI, and an area with unresolved questions. While more research is needed to quantify the risk of deficiencies in special populations, and establish the natural history, increasing data indicate an increase in hypopituitarism after other acquired brain injuries; the potential role of pituitary hormone deficiencies after stroke and after COVID-19 infection is an area of active inquiry. Given the negative health effects of untreated hypopituitarism and the opportunity to intervene via hormone replacement, it is important to recognize the role of pituitary hormone deficiencies after TBI.

The effectiveness of cold oral stimuli in quenching postoperative thirst: A systematic review and meta-analysis

OBJECTIVE

To examine the effectiveness of cold oral stimuli in quenching postoperative thirst in patients undergoing surgery.

DESIGN

A systematic review and meta-analysis of interventional studies.

SETTING

Postoperative care units.

METHODS

Seven electronic databases (Medline, Scopus, Web of Science, PubMed, CINHAL, PsycInfo, and EMBASE) were systematically searched from their inception to January 12, 2022. The Cochrane Handbook for Systematic Reviews of Interventions was followed. Two researchers examined the study quality using the Cochrane risk of bias tools. A meta-analysis with a subgroup analysis was performed. Sensitivity analysis, funnel plots and Egger's test were used to examine publication bias.

MAIN OUTCOME MEASURE

A thirst intensity score was used to rate postoperative thirst.

RESULTS

Data were collected from 11 interventional studies for this systematic review. Eight studies underwent a meta-analysis with a total of 1504 patients. Our meta-analysis showed that the thirst intensity scores decreased in the experimental groups by 1.42 points (95% confidence interval: -2.162 to -0.684) more than those of the control groups. Subgroup analysis indicated that Asian patients and age were two factors that moderated the thirst intensity score after applying cold oral stimuli.

CONCLUSION

Cold oral stimuli were effective in mitigating postoperative thirst. Ice products such as ice cubes, or ice chips are easily available in postoperative units. When applying cold oral stimuli, health professionals should be aware of that in Asian and older patients. Cultural acceptance and physiological degeneration, respectively, may influence the thirst ratings. Future research should investigate various factors underlying the perioperative period. Network meta-analysis can be used to examine multiple strategies for thirst management.

Patient perspectives on indwelling urinary catheters and fluid balances after transsphenoidal pituitary surgery: a qualitative study

OBJECTIVES

To explore the perceptions and experiences of patients who underwent transsphenoidal pituitary gland and (para)sellar tumour surgery regarding indwelling urinary catheters (IDUCs) and the postoperative fluid balance.

DESIGN

Qualitative study using semistructured interviews based on the attitudes, social influence and self-efficacy model and expert knowledge.

PARTICIPANTS

Twelve patients who underwent transsphenoidal pituitary gland tumour surgery and received an IDUC during or after surgery.

SETTING

One patient was interviewed in the endocrinology outpatient clinic and 11 patients were interviewed on the neurosurgery ward.

RESULTS

Five major themes emerged: (1) conflicting information and preoperative expectations, (2) IDUCs perceived as patient-friendly during bedrest, particularly for women, (3) little room for patients' opinions, (4) physical and emotional limitations and (5) fluid balance causes confusion. Information regarding IDUC placement and fluid balance given to patients both preoperatively and postoperatively did not meet their expectations, which led to confusion and uncertainty. The IDUC was perceived as preferable if bedrest was mandatory, preferred particularly by women. Patient could not mobilise freely due to the IDUC and felt ashamed, judged by others and dependent on nurses.

CONCLUSIONS

This study provides insight into the challenges patients experience in relation to the IDUC and fluid balance. Perceptions on the necessity of an IDUC varied among patients and were influenced by both physical and emotional impediments. A clear, frequent and daily communication between healthcare professionals and patients to evaluate IDUC and fluid balance use is necessary to increase patient satisfaction.

Traumatic Brain Injury as a Potential Risk Factor for Diabetes Mellitus in the Veteran Population

This review examines various aspects of traumatic brain injury (TBI) and its potential role as a causative agent for type 2 diabetes mellitus (T2DM) in the veteran population. The pituitary glands and the hypothalamus, both housed in the intracranial space, are the most important structures for the homeostatic regulation of almost every hormone in the human body. As such, TBI not only causes psychological and cognitive impairments but can also disrupt the endocrine system. It is well established that in addition to having a high prevalence of chronic traumatic encephalopathy (CTE), veterans have a very high risk of developing various chronic medical conditions. Unfortunately, there are no measures or prophylactic agents that can have a meaningful impact on this medically complex patient population. In this review, we explore several important factors pertaining to both acute and chronic TBI that can provide additional insight into why veterans tend to develop T2DM later in life. We focus on the unique combination of risk factors in this population not typically found in civilians or other individuals with a non-military background. These include post-traumatic stress disorder, CTE, and environmental factors relating to occupation and lifestyle.

Magnetic resonance imaging, clinicopathologic findings, and clinical progression of a puppy with confirmed Eastern equine encephalitis virus

A 5-month-old puppy was evaluated for rapidly progressive neurologic signs and pyrexia. Magnetic resonance imaging showed multifocal meningoencephalitis with transtentorial and foramen magnum herniation. A cerebrospinal fluid tap revealed highly cellular fluid, and the puppy was euthanized. Histopathology showed lymphoplasmacytic and neutrophilic meningoencephalitis. Viral polymerase chain reaction testing for Eastern equine encephalitis was positive. Rapid progression of neurologic signs and respiratory arrest necessitated mechanical ventilation. Severe hypernatremia, most consistent with central diabetes insipidus, developed. Key clinical message: Transtentorial and foramen magnum herniation and high cerebrospinal fluid cell counts may be indicators of poor prognosis. Brain death, respiratory arrest, and central diabetes insipidus may also ensue with Eastern equine encephalitis infection.

Diabetes insipidus

Diabetes insipidus (DI) is a disorder characterized by a high hypotonic urinary output of more than 50ml per kg body weight per 24 hours, with associated polydipsia of more than 3 liters a day [1,2]. Central DI results from inadequate secretion and usually deficient synthesis of Arginine vasopressin (AVP) in the hypothalamus or pituitary gland. Besides central DI further underlying etiologies of DI can be due to other primary forms (renal origin) or secondary forms of polyuria (resulting from primary polydipsia). All these forms belong to the Polyuria Polydipsia Syndrom (PPS). In most cases central and nephrogenic DI are acquired, but there are also congenital forms caused by genetic mutations of the AVP gene (central DI) [3] or by mutations in the gene for the AVP V2R or the AQP2 water channel (nephrogenic DI) [4]. Primary polydipsia (PP) as secondary form of polyuria includes an excessive intake of large amounts of fluid leading to polyuria in the presence of intact AVP secretion and appropriate antidiuretic renal response. Differentiation between the three mentioned entities is difficult [5], especially in patients with Primary polydipsia or partial, mild forms of DI [1,6], but different tests for differential diagnosis, most recently based on measurement of copeptin, and a thorough medical history mostly lead to the correct diagnosis. This is important since treatment strategies vary and application of the wrong treatment can be dangerous [7]. Treatment of central DI consists of fluid management and drug therapy with the synthetic AVP analogue Desmopressin (DDAVP), that is used as nasal or oral preparation in most cases. Main side effect can be dilutional hyponatremia [8]. In this review we will focus on central diabetes insipidus and describe the prevalence, the clinical manifestations, the etiology as well as the differential diagnosis and management of central diabetes insipidus in the out- and inpatient setting.

Role of copeptin in the diagnosis of traumatic neuroendocrine dysfunction

Traumatic neuroendocrine dysfunction may present with diabetes insipidus (DI) or with the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Both these pathologies involve a disturbance in the antidiuretic hormone (ADH) secretion, causing dysnatremias. Diagnosis of posttraumatic ADH dysfunction is hampered by technical difficulties in ADH assessment, and relies mostly on non-specific serum sodium, serum and urine osmolality and diuresis, often leading to misdiagnosis in the acute care setting. Research now focuses on the diagnostic role of copeptin, a peptide secreted together with ADH in an equimolar fashion, and which can be accurately evaluated. Recent studies identified cut-off values of 2.6 pmol/L for baseline copeptin and of 4.9 and 3.8 pmol/L for hypertonic saline infusion and arginine infusion stimulated copeptin, respectively, for the diagnosis of DI in patients with polyuria-polydipsia syndrome. Although SIADH is more difficult to be explored due to its heterogeneity, a ratio of copeptin to urinary sodium below 30 pmol/mmol identifies euvolemic hyponatremia. Exploring the role of copeptin assessment in patients with traumatic brain injury (TBI) in the acute phase may improve their diagnosis accuracy, management and outcome.

Late magnetic resonance imaging findings in trauma-induced central diabetes insipidus: Case report and review of literature

We presented the late magnetic resonance imaging characteristics in a 47-year-old male who diagnosed with a permanent trauma-induced diabetes insipidus. The patient developed polyuria following a deceleration injury which has been diagnosed as central diabetes insipidus based on the water deprivation test. Computed tomography or magnetic resonance evaluation of the pituitary gland is usually normal in such cases. Therefore, negative imaging studies do not exclude the diagnosis. However, MRI is more sensitive and can depict subtle injuries of the hypothalamus-pituitary axis in acute and late phases. The late MR imaging findings are not well established. To the best of our knowledge, this will be the first report to describe the late MR imaging features in a permanent case of trauma-induced diabetes insipidus.

Mismatch between Tissue Partial Oxygen Pressure and Near-Infrared Spectroscopy Neuromonitoring of Tissue Respiration in Acute Brain Trauma: The Rationale for Implementing a Multimodal Monitoring Strategy

The brain tissue partial oxygen pressure (PbtO₂) and near-infrared spectroscopy (NIRS) neuromonitoring are frequently compared in the management of acute moderate and severe traumatic brain injury patients; however, the relationship between their respective output parameters flows from the complex pathogenesis of tissue respiration after brain trauma. NIRS neuromonitoring overcomes certain limitations related to the heterogeneity of the pathology across the brain that cannot be adequately addressed by local-sample invasive neuromonitoring (e.g., PbtO₂ neuromonitoring, microdialysis), and it allows clinicians to assess parameters that cannot otherwise be scanned. The anatomical co-registration of an NIRS signal with axial imaging (e.g., computerized tomography scan) enhances the optical signal, which can be changed by the anatomy of the lesions and the significance of the radiological assessment. These arguments led us to conclude that rather than aiming to substitute PbtO₂ with tissue saturation, multiple types of NIRS should be included via multimodal systemic- and neuro-monitoring, whose values then are incorporated into biosignatures linked to patient status and prognosis. Discussion on the abnormalities in tissue respiration due to brain trauma and how they affect the PbtO₂ and NIRS neuromonitoring is given.

Neuroimaging of central diabetes insipidus

Central diabetes insipidus (CDI) occurs secondary to deficient synthesis or secretion of arginine vasopressin peptide from the hypothalamo-neurohypophyseal system (HNS). It is characterized by polydipsia and polyuria (urine output >30mL/kg/day in adults and >2l/m²/24h in children) of dilute urine (<250mOsm/L). It can result from any pathology affecting one or more components of the HNS including the hypothalamic osmoreceptors, supraoptic or paraventricular nuclei, and median eminence of the hypothalamus, infundibulum, stalk or the posterior pituitary gland. MRI is the imaging modality of choice for evaluation of the hypothalamic-pituitary axis (HPA), and a dedicated pituitary or sella protocol is essential. CT can provide complimentary diagnostic information and is also of value when MRI is contraindicated. The most common causes are benign or malignant neoplasia of the HPA (25%), surgery (20%), and head trauma (16%). No cause is identified in up to 30% of cases, classified as idiopathic CDI. Knowledge of the anatomy and physiology of the HNS is crucial when evaluating a patient with CDI. Establishing the etiology of CDI with MRI in combination with clinical and biochemical assessment facilitates appropriate targeted treatment. This chapter illustrates the wide variety of causes and imaging correlates of CDI on neuroimaging, discusses the optimal imaging protocols, and revises the detailed neuroanatomy required to interpret these studies.

Adipsic diabetes insipidus

Adipsic diabetes insipidus (ADI) is a rare but devastating disorder of water balance with significant associated morbidity and mortality. Most patients develop the disease as a result of hypothalamic destruction from a variety of underlying etiologies. Damage to osmolar-responsive neuroreceptors, primarily within the supraoptic and paraventricular nuclei, results in impaired production and release of arginine vasopressin (AVP). Important regulating circuits of thirst sense and drive are regionally colocalized with AVP centers and therefore are also injured. Patients with central diabetes insipidus with impaired thirst response, defined as ADI, suffer from wide swings of plasma osmolality resulting in repeated hospitalization, numerous associated comorbidities, and significant mortality. Treatment recommendations are based largely on expert advice from case series owing to the rarity of disease prevalence. Acute disease management focuses on fixed dosing of antidiuretic hormone analogues and calculated prescriptions of obligate daily water intake. Long-term care requires patient/family education, frequent reassessment of clinical and biochemical parameters, as well as screening and treatment of comorbidities.

Risk factors and predictive model of adrenocortical insufficiency in patients with traumatic brain injury

BACKGROUND

Neuroendocrine dysfunction after traumatic brain injury (TBI) has received increased attention due to its impact on the recovery of neural function. The purpose of this study is to investigate the incidence and risk factors of adrenocortical insufficiency (AI) after TBI to reveal independent predictors and build a prediction model of AI after TBI.

METHODS

Enrolled patients were grouped into the AI and non-AI groups. Fourteen preset impact factors were recorded. Patients were regrouped according to each impact factor as a categorical variable. Univariate and multiple logistic regression analyses were performed to screen the related independent risk factors of AI after TBI and develop the predictive model.

RESULTS

A total of 108 patients were recruited, of whom 34 (31.5%) patients had AI. Nine factors (age, Glasgow Coma Scale [GCS] score on admission, mean arterial pressure [MAP], urinary volume, serum sodium level, cerebral hernia, frontal lobe contusion, diffuse axonal injury [DAI], and skull base fracture) were probably related to AI after TBI. Three factors (urinary volume [X ₄], serum sodium level [X ₅], and DAI [X ₈]) were independent variables, based on which a prediction model was developed (logit P= -3.552+2.583X ₄+2.235X ₅+2.269X ₈).

CONCLUSIONS

The incidence of AI after TBI is high. Factors such as age, GCS score, MAP, urinary volume, serum sodium level, cerebral hernia, frontal lobe contusion, DAI, and skull base fracture are probably related to AI after TBI. Urinary volume, serum sodium level, and DAI are the independent predictors of AI after 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.

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.

Acute onset of central diabetes insipidus during adolescent idiopathic scoliosis surgery

This is a case report of a 12-year-old female with idiopathic scoliosis undergoing posterior scoliosis reconstruction that developed an acute onset of central diabetes insipidus (CDI) during surgery. The diagnosis was made as a result of an intraoperative increase in urine output to 6.82 ml/kg/hour (550 ml), a serum sodium increase from 139 to 147 mmol/L, a serum osmolality of 299 mOsmol/kg, a rapid response to vasopressin administration and a low vasopressin level of < 0.5 picograms/ml (normal, 1-5 picograms/ml). This is the first reported case of CDI with a documented low vasopressin level that has occurred in a pediatric scoliosis surgical patient.

Nocturia in patients with cognitive dysfunction: a systematic review of the literature

Background

The objective of this study is to evaluate current literature on the association between cognitive dysfunction and nocturia.

Methods

A systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was conducted through MEDLINE, EMBASE and COCHRANE databases and completed in November 2019. Randomized and non-randomized studies were included if they assessed the association between cognitive dysfunction and nocturia in older participants with or without neurological diseases. The quality of included studies was evaluated using the Risk of Bias Assessment tool for Non-randomized Studies (RoBANS).

Results

A total of 8 cross-sectional studies conducted in older patient populations met the criteria for inclusion. A statistically significant association was identified in 6 studies on univariate analysis, which persisted in 2 studies after controlling for confounding factors. The association between cognitive dysfunction and nocturia was positive for all 6 significant analyses. The overall risk of bias was unclear.

Conclusion

A significant positive association between cognitive dysfunction and nocturia was identified. However, research has been limited to cross-sectional studies, which precludes identification of causality between cognitive dysfunction and nocturia. Heightened awareness of the complex interplay between cognition and nocturia would allow professionals involved in the care of cognitively impaired patients with concomitant nocturia to more effectively manage these symptoms.

Incidence and Effect of Diabetes Insipidus in the Acute Care of Patients with Severe Traumatic Brain Injury

BACKGROUND

Literature on diabetes insipidus (DI) after severe traumatic brain injury (TBI) is scarce. Some studies have reported varying frequencies of DI and have showed its association with increased mortality, suggesting it as a marker of poor outcome. This knowledge gap in the acute care consequences of DI in severe TBI patients led us to conceive this study, aimed at identifying risk factors and quantifying the effect of DI on short-term functional outcomes and mortality.

METHODS

We assembled a historic cohort of adult patients with severe TBI (Glasgow Coma Scale ≤ 8) admitted to the intensive care unit (ICU) of a tertiary-care university hospital over a 6-year period. Basic demographic characteristics, clinical information, imaging findings, and laboratory results were collected. We used logistic regression models to assess potential risk factors for the development of DI, and the association of this condition with death and unfavorable functional outcomes [modified Rankin scale (mRS)] at hospital discharge.

RESULTS

A total of 317 patients were included in the study. The frequency of DI was 14.82%, and it presented at a median of 2 days (IQR 1-3) after ICU admission. Severity according to the Abbreviated Injury Scale (AIS) score of the head, intracerebral hemorrhage, subdural hematoma, and skull base fracture was suggested as risk factors for DI. Diagnosis of DI was independently associated death (OR 4.34, CI 95% 1.92-10.11, p = 0.0005) and unfavorable outcome (modified Rankin Scale = 4-6) at discharge (OR 7.38; CI 95% 2.15-37.21, p = 0.0047).

CONCLUSIONS

Diabetes insipidus is a frequent and early complication in patients with severe TBI in the ICU and is strongly associated with increased mortality and poor short-term outcomes. We provide clinically useful risk factors that will help detect DI early to improve prognosis and therapy of patients with severe TBI.

Serum sodium and intracranial pressure changes after desmopressin therapy in severe traumatic brain injury patients: a multi-centre cohort study

Background

In traumatic brain injury (TBI) patients desmopressin administration may induce rapid decreases in serum sodium and increase intracranial pressure (ICP).

Aim

In an international multi-centre study, we aimed to report changes in serum sodium and ICP after desmopressin administration in TBI patients.

Methods

We obtained data from 14 neurotrauma ICUs in Europe, Australia and UK for severe TBI patients (GCS ≤ 8) requiring ICP monitoring. We identified patients who received any desmopressin and recorded daily dose, 6-hourly serum sodium, and 6-hourly ICP.

Results

We studied 262 severe TBI patients. Of these, 39 patients (14.9%) received desmopressin. Median length of treatment with desmopressin was 1 [1–3] day and daily intravenous dose varied between centres from 0.125 to 10 mcg. The median hourly rate of decrease in serum sodium was low (− 0.1 [− 0.2 to 0.0] mmol/L/h) with a median period of decrease of 36 h. The proportion of 6-h periods in which the rate of natremia correction exceeded 0.5 mmol/L/h or 1 mmol/L/h was low, at 8% and 3%, respectively, and ICPs remained stable. After adjusting for IMPACT score and injury severity score, desmopressin administration was independently associated with increased 60-day mortality [HR of 1.83 (1.05–3.24) (p = 0.03)].

Conclusions

In severe TBI, desmopressin administration, potentially representing instances of diabetes insipidus is common and is independently associated with increased mortality. Desmopressin doses vary markedly among ICUs; however, the associated decrease in natremia rarely exceeds recommended rates and median ICP values remain unchanged. These findings support the notion that desmopressin therapy is safe.

Lateral fluid-percussion injury leads to pituitary atrophy in rats

Traumatic brain injury (TBI) causes neuroendocrine dysregulation in up to 40% of humans, which is related to impaired function of the hypothalamo-hypophyseal axis and contributes to TBI-related co-morbidities. Our objective was to investigate whether hypophyseal atrophy can be recapitulated in rat lateral fluid-percussion injury model of human TBI. High-resolution structural magnetic resonance images (MRI) were acquired from rats at 2 days and 5 months post-TBI. To measure the lobe-specific volumetric changes, manganese-enhanced MRI (MEMRI) scans were acquired from rats at 8 months post-TBI, which also underwent the pentylenetetrazol (PTZ) seizure susceptibility and Morris water-maze spatial memory tests. MRI revealed no differences in the total hypophyseal volume between TBI and controls at 2 days, 5 months or 8 months post-TBI. Surprisingly, MEMRI at 8 months post-TBI indicated a 17% reduction in neurohypophyseal volume in the TBI group as compared to controls (1.04 ± 0.05 mm³ vs 1.25 ± 0.05 mm³, p < 0.05). Moreover, neurohypophyseal volume inversely correlated with the number of PTZ-induced epileptiform discharges and the mean latency to platform in the Morris water-maze test. Our data demonstrate that TBI leads to neurohypophyseal lobe-specific atrophy and may serve as a prognostic biomarker for post-TBI outcome.

Successful Treatment of Transient Central Diabetes Insipidus following Traumatic Brain Injury in a Dog

An 11-year-old female spayed Maltese presented comatose, half an hour after vehicular trauma, and was treated for traumatic brain injury and pulmonary contusions. The dog developed severe hypernatremia within six hours of presentation, which responded poorly to the administration of five percent dextrose in water. As central diabetes insipidus was suspected, desmopressin was trialled and resolution of hypernatremia was achieved six days later. Transient trauma-induced central diabetes insipidus has been described previously in two dogs; in the first, serum sodium concentrations were evaluated three days after injury and the other developed hypernatremia seven days after injury. To the authors' knowledge, this is the first report of rapid onset, transient, and trauma-induced central diabetes insipidus in a dog that encompasses the complete clinical progression of the syndrome from shortly after injury through to resolution.

Fifteen-minute consultation: Polydipsia, polyuria or both

Children can present with polydipsia and/or polyuria for a number of reasons. We will discuss polydipsia and polyuria, how a child may present and how to investigate further in order to establish the cause. We highlight the important areas to cover in the history and examination of a child presenting with polydipsia and/or polyuria.

Posterior pituitary dysfunction following traumatic brain injury: review

Neurohypophysial dysfunction is common in the first days following traumatic brain injury (TBI), manifesting as dysnatremia in approximately 1 in 4 patients. Both hyponatremia and hypernatremia can impair recovery from TBI and in the case of hypernatremia, there is a significant association with excess mortality. Hyponatremia secondary to syndrome of inappropriate antidiuretic hormone secretion (SIAD) is the commonest electrolyte disturbance following TBI. Acute adrenocorticotropic hormone (ACTH)/cortisol deficiency occurs in 10-15% of TBI patients and can present with a biochemical picture identical to SIAD. For this reason, exclusion of glucocorticoid deficiency is of particular importance in post-TBI SIAD. Cerebral salt wasting is a rare cause of hyponatremia following TBI. Hyponatremia predisposes to seizures, reduced consciousness, and prolonged hospital stay. Diabetes insipidus (DI) occurs in 20% of cases following TBI; where diminished consciousness is present, appropriate fluid replacement of renal water losses is occasionally inadequate, leading to hypernatremia. Hypernatremia is strongly predictive of mortality following TBI. Most cases of DI are transient, but persistent DI is also predictive of mortality, irrespective of plasma sodium concentration. Persistent DI may herald rising intracranial pressure due to coning. True adipsic DI is rare following TBI, but patients are vulnerable to severe hypernatremic dehydration, exacerbation of neurologic deficits and hypothalamic complications, therefore clinicians should be aware of this possible variant of DI.

Permanent central diabetes insipidus after mild head injury

We report a case of a patient with mild traumatic brain injury (TBI) who was diagnosed with permanent central diabetes insipidus (DI). A 21-year-old man was admitted to our outpatient clinic with polyuria and polydipsia 1 week after a mild head injury. He was well, except for these complaints. The initial laboratory workup was consistent with DI. There was no abnormality with other laboratory and hormone values. MRI showed lack of neurohypophyseal hyperintensity with no other abnormal findings. The patient responded well to desmopressin therapy. At the first year of the diagnosis, the patient still needed to use desmopressin treatment as we concluded that DI is permanent. DI is not uncommon after TBI, but it is often seen after severe TBI. We present here an extraordinary case of developing permanent DI after mild TBI with the absence of neurohypophyseal bright spot on MRI with no other abnormal findings.

Making sense of gut feelings in the traumatic brain injury pathogenesis

Traumatic brain injury (TBI) is a devastating condition which often initiates a sequel of neurological disorders that can last throughout lifespan. From metabolic perspective, TBI also compromises systemic physiology including the function of body organs with subsequent malfunctions in metabolism. The emerging panorama is that the effects of TBI on the periphery strike back on the brain and exacerbate the overall TBI pathogenesis. An increasing number of clinical reports are alarming to show that metabolic dysfunction is associated with incidence of long-term neurological and psychiatric disorders. The autonomic nervous system, associated hypothalamic-pituitary axis, and the immune system are at the center of the interface between brain and body and are central to the regulation of overall homeostasis and disease. We review the strong association between mechanisms that regulate cell metabolism and inflammation which has important clinical implications for the communication between body and brain. We also discuss the integrative actions of lifestyle interventions such as diet and exercise on promoting brain and body health and cognition after TBI.

Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) and Subsequent Central Diabetes Insipidus: A Rare Presentation of Pituitary Apoplexy

Pituitary apoplexy (PA) is a rare endocrine emergency that occasionally presents with sodium disturbances. Here we present a rare case with a previously healthy 41-year-old female who presented with acute onset headache and nausea without visual impairment or overt pituitary dysfunction. Plasma sodium concentrations declined abruptly during the first two days of admission to a nadir of 111 mmol/l. Urine and blood chemistry were consistent with syndrome of inappropriate antidiuretic hormone secretion (SIADH). Magnetic resonance imaging revealed recent bleeding into a pituitary cystic process. Hyponatremia was successfully corrected with fluid restriction and both visual function and anterior pituitary function remained intact. Subsequently, the patient developed central diabetes insipidus (CDI), which responded well to desmopressin substitution. To our knowledge, this is the first case of PA presenting predominantly with posterior pituitary dysfunction that transitioned from SIADH to permanent CDI.

Hypernatremia and Coagulopathy May or May Not Be Useful Clinical Biomarkers in Dogs with Head Trauma: A Retrospective Study

This study was performed to evaluate clinical biomarkers as prognostic values in dogs with traumatic brain injury (TBI) based on findings in human patients. Sodium levels of 158 dogs with TBI and 169 patients with trauma without involvement of the head except head trauma (EHT) were examined. TBI patients with hypernatremia had a slightly higher risk of dying (22.03 %) than dogs with normal sodium levels (19.76%). However, there was no significant correlation between sodium levels and outcome in TBI patients (p = 0.6357). Dogs with sodium levels >160 mmol/L were non-survivors. In dogs with late-onset post-traumatic epilepsy (PTE) more often hyponatremia was measured, and in dogs with immediate PTE mild hypernatremia or normal sodium levels were measured after the trauma. Evaluation of coagulation parameters in a subpopulation of dogs showed a strong correlation between partial thromboplastin time/prothrombin time (PTT/PT) and the Modified Glasgow Coma Scale (MGCS) (p = 0.0006; p = 0.0306). In conclusion, unlike in human patients, sodium levels displayed no significant correlation with survival in dogs with TBI in the current study. However, in cases with severe TBI, dog owners often elect euthanasia before severe hypernatremia can be measured. Late PTE was observed in cases with initial hyponatremia. Because of a significant correlation between PTT/PT and MGCS, coagulopathy might be considered as a prognostic clinical biomarker in canine TBI patients.

Triphasic response of pituitary stalk injury following TBI: a relevant yet uncommonly recognised endocrine phenomenon

The triphasic response of pituitary stalk injury has previously been described in a minority of patients following intracranial surgery, however, this phenomenon can also occur after traumatic brain injury. We present the case of a 20-year-old male who experienced the triphasic response of pituitary stalk injury (central diabetes insipidus, syndrome of inappropriate antidiuretic hormone and central diabetes insipidus again) after striking his head on a concrete curb. His history and presentation highlight the importance of recognising the distinctive symptoms of each individual stage of pituitary stalk injury, and using the appropriate diagnostic tools and therapies to guide further management.

Intracranial pathologies associated with central diabetes insipidus in infants

Background Idiopathic central diabetes insipidus (CDI) has been associated with intracranial pathologies that do not involve the structural pituitary gland or hypothalamus. The objective was to study the association between non-structural hypothalamic/pituitary intracranial pathologies (NSHPIP) with CDI and to review etiologies that may be contributory to the development of CDI. Methods A retrospective query of our intra-institutional database from 2006 to 2015. Children admitted diagnosed with diabetes insipidus (DI) (ICD-9 253.5) between the ages of 0-1 year were included. Patient charts were reviewed to include those who have a documented diagnosis of CDI, hypernatremia (>145 mmol/L), high serum osmolality (>300 mOsm/kg), low urine osmolality (<300 mOsm/kg), and brain imaging reports. Diagnoses of nephrogenic DI were excluded. Results Twenty-three infant patients were diagnosed with CDI. Eleven subjects (48%) had NSHPIP. Of those, 18% had cerebral infarction, 27% had intracranial injury and hemorrhage due to traumatic brain injury, 18% had isolated intraventricular hemorrhage, and 27% had meningitis. Hospital prevalence for NSHPIP, age 0-1 year, ranged from 0.05% to 0.3%. Conclusions Rates of NSHPIP in those with CDI are higher than expected hospital rates (p<0.001), suggesting a possible association between CDI and NSHPIP.

Chronic Health Illnesses as Predictors of Mild Cognitive Impairment Among African American Older Adults

Approximately 5.5 million individuals are diagnosed with Alzheimer's disease (AD) dementia, a number which includes those with mild cognitive impairment and asymptomatic individuals with biomarkers of AD. There is a higher incidence of mild cognitive impairment (MCI) in African American populations as compared to White populations, even when controlling for sociodemographic factors. The existing body of ethnically/racially targeted research on MCI has been limited by few studies with the ability to generalize to African American communities. This study sought to examine whether medical conditions which occur at a higher rate in African American individuals increase the hazard of subsequent MCI development. A secondary data analysis of the National Alzheimer's Coordinating Center Uniform Data Set was employed to examine the associations between health conditions (congestive heart failure, traumatic brain injury, diabetes, hypertension, hypercholesterolemia, B12 deficiency, thyroid disease) and their relationship to MCI. The analytic sample included 2847 participants with 9872 observations. Binary logistic generalized estimating equation modeling was used to examine repeated measures over the course of 1-11 observations. Education was associated with MCI development, specifically those with some college or college graduates (p < 0.001) and more than college (p = 0.002). Female sex was associated with development of MCI (p < 0.001). African Americans with traumatic brain injury (TBI) were more likely to develop MCI (p < 0.001) compared to those with no reports of a TBI. Inactive thyroid conditions decreased the risk of MCI development (p = 0.005) compared to those without thyroid disease. Though vascular factors are often attributed to higher mortality and neurodegeneration in African Americans, congestive heart failure, diabetes, high cholesterol, hypertension, diabetes, nor seizures were associated with an increased risk of MCI development. Findings from this study provide formative data to develop targeted interventions for subsets of the African American community, including those with higher educational levels, those with TBI, and those with a history of thyroid disease. While it may not be possible to prevent MCI development, it is possible to modify lifestyle behaviors contributing to these health conditions, such as falls that are often experienced by older adults. Practitioners can increase awareness, knowledge, and resources relevant to clients.

Sushi repeat-containing protein X-linked 2: A novel phylogenetically conserved hypothalamo-pituitary protein

Sushi repeat-containing protein X-linked 2 (SRPX2) is a novel protein associated with language development, synaptic plasticity, tissue remodeling, and angiogenesis. We investigated the expression and spatial localization of SRPX2 in normal mouse, rat, monkey, and human brain using in situ hybridization and immunohistochemistry. Antibody specificity was determined using in vitro siRNA based silencing of SRPX2. Cell type-specific expression was verified by double-labeling with oxytocin or vasopressin. Western blot was used to detect SRPX2 protein in rat and human plasma and cerebrospinal fluid. Unexpectedly, SRPX2 mRNA expression levels were strikingly higher in the hypothalamus as compared to the cortex. All SRPX2 immunoreactive (ir) neurons were localized in the hypothalamic paraventricular, periventricular, and supraoptic nuclei in mouse, rat, monkey, and human brain. SRPX2 colocalized with vasopressin or oxytocin in paraventricular and supraoptic neurons. Hypothalamic SRPX2-ir positive neurons gave origin to dense projections traveling ventrally and caudally toward the hypophysis. Intense axonal varicosities and terminal arborizations were identified in the rat and human neurohypophysis. SRPX2-ir cells were also found in the adenohypophysis. Light SRPX2-ir projections were observed in the dorsal and ventral raphe, locus coeruleus, and the nucleus of the solitary tract in mouse, rat and monkey. SRPX2 protein was also detected in plasma and CSF. Our data revealed intense phylogenetically conserved expression of SRPX2 protein in distinct hypothalamic nuclei and the hypophysis, suggesting its active role in the hypothalamo-pituitary axis. The presence of SRPX2 protein in the plasma and CSF suggests that some of its functions depend on secretion into body fluids.

The retrotransposon gag domain containing protein Rgag4 is an Ikaros target in the pituitary

Previous studies have established the common and critical involvement of the zinc finger protein Ikaros in lymphoid and pituitary cell development and expansion. Key to the assembly of several transcriptional networks, we have demonstrated up-regulation of Ikaros and its interacting partner the C-terminal Binding Protein (CtBP) in response to hypoxia. This prompted us to explore common transcriptional targets using a chromatin immunoprecipitate (ChIP) screen of DNA from pituitary corticotroph cells. This strategy yielded a finite list of targets common to both transcription factors that included the metalloprotease ADAMTS10. In this report, we focus on validation of a second candidate target, the retrotransposon gag domain containing protein Rgag4. We identified the ability of Ikaros to bind the Rgag4 promoter, influence its transcriptional activity, and induce endogenous gene expression. Robust expression of Rgag4 was noted in the anterior lobe of the pituitary gland which was diminished in Ikaros knockout mice. Down-regulation of Rgag4 resulted in profound reduction of hormone gene expression with diminished ACTH secretion, recapitulating the effect of Ikaros deficiency in knockout mice. The results introduce Rgag4 to the repertoire of effectors serving to couple the chromatin remodeler Ikaros with the hormonal stress response.

Transient Diabetes Insipidus Following Thermal Burn; A Case Report and Literature Review

Diabetes insipidus is a disease charaterised by increased urine production and thrist. Neurogenic diabetes insipidus following head trauma,autoimmune disease and infection is quite common but diabetes insipidus following thermal burn injury is a rare complication.We should know about this complication as its management need a comprehensive approach for satisfactory outcome. Thermal burn can cause different complications in early post burn period like electrolyte imbalance, dehydration, acute renal failure, but diabetes insipidus is a very rare and unusual complication that may come across in thermal burn. We should be aware about this condition to prevent and treat mortality and morbidity in burn patients. We have reported a case of transient diabetes insipidus in a patient of thermal burn in early post burn period. Patient was treated accordingly, leading to complete recovery.

Transient Diabetes Insipidus Following Thermal Burn; A Case Report and Literature Review

Diabetes insipidus is a disease charaterised by increased urine production and thrist. Neurogenic diabetes insipidus following head trauma,autoimmune disease and infection is quite common but diabetes insipidus following thermal burn injury is a rare complication.We should know about this complication as its management need a comprehensive approach for satisfactory outcome. Thermal burn can cause different complications in early post burn period like electrolyte imbalance, dehydration, acute renal failure, but diabetes insipidus is a very rare and unusual complication that may come across in thermal burn. We should be aware about this condition to prevent and treat mortality and morbidity in burn patients. We have reported a case of transient diabetes insipidus in a patient of thermal burn in early post burn period. Patient was treated accordingly, leading to complete recovery.

Diabetes insipidus after discontinuation of vasopressin infusion for septic shock

WHAT IS KNOWN AND OBJECTIVE

Despite widespread use of vasopressin for the treatment of septic shock, few cases of diabetes insipidus (DI) following its discontinuation have been reported.

CASE SUMMARY

A 54-year-old man presented with pneumonia progressing to septic shock, requiring norepinephrine and vasopressin for refractory hypotension. After clinical improvement, the patient on 3 separate occasions developed polyuria and severe hypernatremia upon discontinuation of vasopressin, with prompt recovery upon its resumption.

WHAT IS NEW AND CONCLUSION

Occurrence of DI upon discontinuation of vasopressin infusion appears to be rare, but incidence may be underestimated due to a paucity of published reports. Actual incidence and underlying mechanism of this phenomenon remain to be elucidated.

Diabetes insipidus: The other diabetes

Diabetes insipidus (DI) is a hereditary or acquired condition which disrupts normal life of persons with the condition; disruption is due to increased thirst and passing of large volumes of urine, even at night. A systematic search of literature for DI was carried out using the PubMed database for the purpose of this review. Central DI due to impaired secretion of arginine vasopressin (AVP) could result from traumatic brain injury, surgery, or tumors whereas nephrogenic DI due to failure of the kidney to respond to AVP is usually inherited. The earliest treatment was posterior pituitary extracts containing vasopressin and oxytocin. The synthetic analog of vasopressin, desmopressin has several benefits over vasopressin. Desmopressin was initially available as intranasal preparation, but now the oral tablet and melt formulations have gained significance, with benefits such as ease of administration and stability at room temperature. Other molecules used for treatment include chlorpropamide, carbamazepine, thiazide diuretics, indapamide, clofibrate, indomethacin, and amiloride. However, desmopressin remains the most widely used drug for the treatment of DI. This review covers the physiology of water balance, causes of DI and various treatment modalities available, with a special focus on desmopressin.