SIADH as a Rare Complication of Foramen Magnum Stenosis in an Infant With Achondroplasia.

Achondroplasia is the most common skeletal dysplasia and is associated with serious complications such as foramen magnum stenosis (FMS). This case report describes an infant with achondroplasia who presented with a syndrome of inappropriate antidiuretic hormone secretion (SIADH), secondary to significant FMS and myelocompression. A 2-month-old boy with prenatally diagnosed achondroplasia was referred due to disordered breathing and altered consciousness. On admission, apathy, hypotonus, and hypothermia with typical features of achondroplasia were noticed. Laboratory investigations revealed severe hyponatremia and hypochloridaemia with normal glucose and urea levels. The diagnosis of SIADH was made based on low serum osmolality in the presence of high urine osmolality, along with an elevated copeptin level. An emergency computerized tomography showed a high-grade stenosis at the cranio-cervical junction; subsequent magnetic resonance imaging demonstrated myelocompression. The patient underwent decompression surgery the next day; serum osmolality increased after the operation. Spontaneous breathing after extubation was sufficient whereas tetraplegia persisted despite intensive physiotherapy. Clinicians should be aware of SIADH as a presenting sign of FMS in children with achondroplasia. Further discussion is warranted regarding improving parental education and timing of screening recommendations.

[Herpes simplex encephalitis complicated with cerebral salt wasting syndrome: a case study].

A 78-year-old man was admitted to the hospital with a 4-day history of fever and confusion. Physical examination revealed oral dryness and decreased skin turgor. Blood tests showed hyponatremia (121.5 |mEq/l), and cerebrospinal fluid examination revealed positivity for herpes simplex virus 1 (HSV-1) via polymerase chain reaction. He was diagnosed with herpes simplex encephalitis and initiated acyclovir treatment. The hyponatremia was diagnosed as cerebral salt wasting syndrome (CSWS) and treated with hypertonic saline infusion and fludrocortisone. The cerebrospinal fluid HSV-1 DNA became negative, and the serum sodium levels normalized. Hyponatremia complicated with encephalitis is often caused by the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), whereas CSWS is rare, mostly observed in tuberculous meningitis. Differentiating between the SIADH and CSWS is important as they require distinct therapeutic strategies.

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.

Copeptin's role in traumatic brain injury: The promising quest for a new biomarker.

OBJECTIVE: Traumatic brain injury (TBI) necessitates reliable biomarkers to improve patient care. This study explored copeptin as a potential biomarker in TBI and its relation to vasopressin (ADH) in such patients. METHODS: A cross-sectional study was conducted on 50 TBI patients. Exclusion criteria included specific medical conditions and recent traumatic events. Copeptin and ADH testing were performed within 30 days post-trauma. Patient data, Glasgow Coma Scale (GCS) scores, imaging results, and the need for surgical intervention were obtained from medical charts. RESULTS: Copeptin levels negatively correlated with GCS scores (ρ = - 0.313, p = 0.027), indicating a potential association with trauma severity. Copeptin levels (mean: 3.22 pmol/L, median 2.027 pmol/L, SD = 3.15) tended to be lower than those found in the normal population, suggesting possible neuroendocrine dysfunction post-TBI. ADH levels (mean: 67.93 pmol/L, median 56.474 pmol/L SD = 47.67) were higher than the normal range and associated with the need for surgery (p = 0.048). Surprisingly, copeptin and ADH levels negatively correlated (r = - 0.491; p < 0.001), potentially due to differences in degradation processes and physiological variations in TBI patients. CONCLUSION: Copeptin shows potential as a predictive biomarker for assessing TBI severity and predicting patient outcome. However, its complex relationship with ADH in TBI requires further investigation. Careful interpretation is needed due to potential variations in excretion dynamics and metabolism. Larger studies on TBI patient cohorts are essential to validate copeptin as a reliable biomarker and improve patient care in TBI.

Hyponatremia After Colonoscopy Bowel Preparation: Challenges in Managing Syndrome of Inappropriate Antidiuretic Hormone Without Established Guidelines.

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a condition that leads to free water retention and solute excretion, predisposing patients to hyponatremia. We present the case of a 79-year-old female with a history of SIADH well-controlled with fluid restriction and sodium chloride tablets who presented with hyponatremia after bowel preparation. Her medication regimen was not adjusted before she took the bowel preparation. Her SIADH diagnosis was unknown when she presented but was exemplified by her sodium levels dropping while on a normal saline drip on her third day in the hospital. She was able to successfully take the bowel preparation without hyponatremia after oral urea was added to her regimen. There are currently no clinical guidelines for SIADH patients receiving bowel preparation for colonoscopies and no case reports describing this situation. We discuss the pathophysiology behind the patient's fluctuating sodium levels when on various maintenance fluids and when on fluid restriction. This case concludes that it is imperative to either increase solute intake or increase free water excretion for SIADH patients receiving bowel preparation to prevent potentially deadly hyponatremia.

Exercise-associated Hyponatremia Developing Immediately after a Musical Stage Performance in a Healthy Actress.

Exercise-associated hyponatremia (EAH) is a life-threatening dilutional hyponatremia that typically occurs during or immediately after exercise in endurance athletes. A 49-year-old actress experienced dizziness 15 min after a 2-h stage performance while drinking several bottles of water. Thirty minutes later, the patient fell unconscious and was hospitalized. On admission, she showed dilutional hyponatremia (117 mmol/L) with extremely elevated arginine vasopressin (11.3 pg/mL). After initial treatment with 3% saline, her sodium levels immediately increased, and she recovered consciousness without developing subsequent osmotic demyelination syndrome. This case emphasizes the need for caution against excessive fluid intake during and/or after exercise to avoid EAH, even in non-athletes.

Sertraline Hydrochloride Overdose Resulting in Diabetes Insipidus: A Case Report.

Sertraline hydrochloride belongs to the selective serotonin reuptake inhibitor class of antidepressants, which can cause respiratory depression, hypotension, malignant vomiting, liver function impairment, and other symptoms when taken in excess. To our knowledge, reports of sertraline hydrochloride overdose causing diabetes insipidus in patients are rare. This report describes a unique case of a 17-year-old female patient who developed diabetes insipidus after a one-time oral intake of 20 sertraline hydrochloride tablets (50 mg/tablet) during the later course of treatment. Her symptoms were effectively relieved after treatment with pituitrin.

Syncope and Brugada-Like ECG Pattern in a Patient with Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH).

Syncope is a brief loss of consciousness caused by reduced blood flow to the brain, characterised by sudden onset, short duration and full recovery without intervention. Anamnesis, physical examination and other diagnostic tests such as laboratory analysis and electrocardiogram (ECG) can be conducted to identify the underlying cause of syncope. A Brugada pattern on an ECG in individuals with syndrome of inappropriate antidiuretic hormone secretion (SIADH) who have syncope symptoms may indicate cardiac issues. A 69-year-old man with hypertension and a history of smoking presented with syncope. His vital signs were within normal limits, with no signs of a neurological deficit. The patient met the diagnostic criteria for SIADH, as evidenced by the presence of hyponatraemia (Na 118 mmol/l), a hyperosmolar condition and euvolemia. Upon arrival, a twelve-lead ECG showed ST-segment anomalies that reflected a Brugada ECG pattern. No ventricular arrhythmias were detected during the 24-hour Holter monitoring. Coronary angiography revealed no abnormalities in the coronary arteries. The ECG demonstrated the normalisation of ST elevations and the disappearance of the Brugada ECG pattern after the correction of hyponatraemia. After three months of follow-up the patient, with a normal sodium level, had no episodes of syncope. LEARNING POINTS: Syncope in elderly patients with Brugada-like ECG patterns can arise from cardiac causes, thus necessitating more examinations.Severe hyponatraemia in patients with SIADH can cause syncope and a Brugada-like ECG pattern.Correction of hyponatraemia, after ruling out cardiac causes, can improve syncope and normalise the Brugada-like ECG pattern.

An Unusual Presentation of Neurosarcoidosis in a 64-Year-Old Man: A Case Report.

Sarcoidosis is a multisystem granulomatous disorder with an unknown etiology that typically involves the lungs, skin, and lymph nodes, with neurological involvement being relatively rare. We discuss a case of neurosarcoidosis in a 64-year-old man who initially presented with unexplained cognitive impairment, insomnia, hyponatremia, paresthesias, and weight loss and later developed uveitis, diplopia, and dysphagia. Ultimately, findings of hilar and mediastinal lymphadenopathy on chest computed tomography (CT) resulted in bronchoscopy, which led to the diagnosis. This case highlights a rare presentation of sarcoidosis with an unusual constellation of symptoms. We discuss the difficulty involved in diagnosing this disorder as well as its highly variable course.

Copeptin Stimulation by Combined Intravenous Arginine and Oral LevoDopa/Carbidopa in Healthy Short Children and Children with the Polyuria-Polydipsia Syndrome.

INTRODUCTION: Stimulated copeptin may provide an alternative to water deprivation testing (WDT) in the evaluation of polyuria-polydipsia syndrome (PPS). Though best studied, arginine stimulation alone produces a modest copeptin response in children. We investigated the effectiveness of the arginine + LevoDopa/Carbidopa stimulation test (ALD-ST) for copeptin. METHODS: 47 healthy short children (controls), 10 children with primary polydipsia, and 10 children with AVP deficiency received arginine hydrochloride (500 mg/kg intravenously over 30 min) and Levodopa/carbidopa (10:1 ratio; 175 mg of l-Dopa/m2 BSA) orally. Serum copeptin was measured at 0, 60, 90, and 120 min. RESULTS: In controls, ALD-ST increased copeptin from a median of 7.0 pmol/L (IQR 5.0-10.0) to a peak of 44.0 pmol/L (IQR 21.4-181.0) between 60 and 120 min (p < 0.001). Copeptin peak was higher in subjects who experienced nausea or vomiting (57%) than in those who did not (131.0 pmol/L [IQR 42.5-193.8] vs. 22.7 pmol/L [IQR 16.0-33.7], p < 0.001). While subjects with primary polydipsia had similar baseline (8.5 pmol/L [IQR 8.0-11.0]) and stimulated (125.2 pmol/L [IQR 87.6-174.0]) copeptin levels as controls, subjects with AVP deficiency had lower baseline (2.5 pmol/L [IQR 2.0-3.1]) and peak levels (4.6 pmol/L [IQR 2.4-6.0]). A peak copeptin of ≥9.3 pmol/L best predicted absence of complete or partial AVP deficiency with a sensitivity of 100% and specificity of 80%. CONCLUSIONS: ALD-ST induced a robust peak copeptin in healthy short children and children with primary polydipsia. Nausea/vomiting, a side effect of ALD-ST, amplified the copeptin response. The ALD-ST may be a suitable initial screening test in children with PPS.

Case report: Secondary failure to tolvaptan in a patient with SCLC and paraneoplastic SIADH.

The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is frequent in lung cancer patients. Here, we report a case with persistent hyponatremia, which suggested malignant SIADH and facilitated an early diagnosis of small cell lung cancer (SCLC). A combined radio-chemotherapy led to a partial remission and resolution of SIADH. An early relapse was indicated by reoccurring severe hyponatremia and increased copeptin levels, which were used as surrogate markers for the antidiuretic hormone (ADH). As palliative immunochemotherapy, together with fluid restriction and solute substitution, were unable to control hyponatremia, treatment with the ADH V2-receptor antagonist tolvaptan was initiated. Over time, the dose of tolvaptan needed to be increased, paralleled by a well-documented exponential increase of copeptin levels. In summary and conclusion, this is a rare case of a secondary failure to tolvaptan with unique documentary evidence of increasing copeptin levels. This observation supports the hypothesis that exceedingly high ADH levels may lead to competitive displacement of tolvaptan from the V2 receptor.

Hyponatremia-associated hospital visits are not reduced by early electrolyte testing in older adults starting antidepressants.

BACKGROUND: Clinical practice guidelines recommend early serum electrolyte monitoring when starting antidepressants in older adults due to the increased risk of hyponatremia. It is unclear whether this monitoring improves outcomes. METHODS: Population-based, retrospective cohort study of Ontario adults aged ≥66 years who initiated therapy with a selective serotonin reuptake inhibitor (SSRI) or selective norepinephrine reuptake inhibitor (SNRI) between April 1, 2013, and January 31, 2020. The index date was the date of the first such prescription, and the exposure of interest was serum electrolyte measurement during the subsequent 7 days. The primary outcome was any emergency department or hospital admission with hyponatremia within 8-60 days of antidepressant initiation. Poisson regression models compared individuals who had versus did not have their serum electrolytes tested in the week following SSRI/SNRI initiation, weighting by propensity score-based overlap weights. RESULTS: Among the 420,085 patients aged ≥66 years initiating treatment with an SSRI/SNRI, 26,808 (6.4%) had serum electrolytes measured in the subsequent 7 days and 6109 (1.5%) subsequently presented to hospital with hyponatremia. The time from drug initiation to hospitalization varied (median 29, interquartile range [IQR] 17-44 days), and the median sodium concentration measured in the community (136, IQR 133-138 mmol/L) was marginally higher than those at the time of hospitalization (132, IQR 130-134 mmol/L). Patients who underwent electrolyte testing in the week following SSRI/SNRI treatment were more likely to attend an emergency department (ED) or hospital with hyponatremia within 8-60 days relative to those who did not (relative risk = 2.31, 95% confidence interval: 2.16-2.46). CONCLUSIONS: Testing serum electrolytes in the week after starting an SSRI/SNRI is not associated with a reduced risk of a hospital visit with hyponatremia. These findings do not support current guidelines recommending routine electrolyte monitoring.

Genetic analysis of nephrogenic diabetes insipidus patients: A study on the Iranian population.

INTRODUCTION: Nephrogenic diabetes insipidus (NDI) is a rare genetic disease that causes water imbalance. The kidneys play a crucial role in regulating body fluids by controlling water balance through urine excretion. This highlights their essential function in managing the body's water levels, but individuals with NDI may have excess urine production (polyuria), that leads to excessive thirst (polydipsia). Untreated affected individuals may exhibit poor feeding and failure to thrive. This disease is caused by mutations in the AVPR2 and the AQP2 genes which have the X-linked and autosomal recessive/dominant inheritance, respectively. Both of these genes are expressed in the kidney. METHODS: Twelve Iranian patients from 10 consanguineous families were studied in this project. DNA was extracted from the whole blood samples of the patients and their parents. All coding exons and exon-intron boundaries of the AVPR2 and AQP2 genes were sequenced in the affected individuals, and the identified variants were investigated in the parents. All variants were analyzed according to the ACMG (American College of Medical Genetics and Genomics) guidelines. RESULTS: In this study, 6 different mutations were identified in the patients, including 5 in the AQP2 gene (c.439G>A, c.538G>A, c.140C>T, c.450T>A, and the novel c.668T>C) and 1 in the AVPR2 gene (c.337C>T) in the present study. DISCUSSION: As expected, all the detected mutations in this study were missense. According to the ACMG guideline, the identified mutations were categorized as pathogenic or likely pathogenic. Unlike previous studies which showed more than 90% of mutations were in the AVPR2 gene, and only less than 10% of the mutations were in the AQP2 gene, it was found that more than 90% of our identified mutations located in the AQP2 gene, and only one mutation was observed in the AVPR2 gene, which seems it may be a result of the high rate of consanguineous marriages in the Iranian population. We observed genotype-phenotype correlation in some of our affected individuals, and some of the mutations were observed in unrelated families from same ethnicity which could be suggestive of a founder mutation.

Comparative Safety and Effectiveness of Urea and Tolvaptan for the Management of Hyponatremia.

Background: The optimal management of euvolemic and hypervolemic hyponatremia remains controversial. The effectiveness of the vasopressin receptor antagonist tolvaptan on serum sodium normalization has been well described in the literature, although the associated risk of serum sodium overcorrection limits its use. Urea has been proposed as an alternative treatment option due to its milder serum sodium raising effects and adverse event profile. Objective: This study aimed to compare urea and tolvaptan for their serum sodium raising effects and potential for overcorrection. Methods: In a multicenter retrospective review, 46 hospitalized patients who received either urea or tolvaptan for the management of hyponatremia were evaluated for the rate of serum sodium normalization and overcorrection. Results: Mean serum sodium concentrations at baseline were 125.91 mEq/L and 123.83 mEq/L for patients treated with urea and tolvaptan, respectively. After 12 hours, tolvaptan was associated with a significantly higher rate of serum sodium increase compared with urea (5.05 mEq/L vs 1.10 mEq/L; P = .001). However, no statistically significant differences were observed in the mean change in serum sodium concentrations at 24 hours, 48 hours, or with the proportion of patients who reached a serum sodium concentration of 135 mEq/L. Overcorrection rates were significantly higher with tolvaptan compared with urea at 43% and 9%, respectively. Conclusion: The results of this study suggest that urea has a comparable effectiveness profile to tolvaptan for the management of hyponatremia with a significantly reduced risk of overcorrection.

Molecular characterization, localization, and physiological roles of ITP and ITP-L in the mosquito, Aedes aegypti.

The insect ion transport peptide (ITP) and its alternatively spliced variant, ITP-like peptide (ITP-L), belong to the crustacean hyperglycemic hormone family of peptides and are widely conserved among insect species. While limited, studies have characterized the ITP/ITP-L signaling system within insects, and putative functions including regulation of ion and fluid transport, ovarian maturation, and thirst/excretion have been proposed. Herein, we aimed to molecularly investigate Itp and Itp-l expression profiles in the mosquito, Aedes aegypti, examine peptide immunolocalization and distribution within the adult central nervous system, and elucidate physiological roles for these neuropeptides. Transcript expression profiles of both AedaeItp and AedaeItp-l revealed distinct enrichment patterns in adults, with AedaeItp expressed in the brain and AedaeItp-l expression predominantly within the abdominal ganglia. Immunohistochemical analysis within the central nervous system revealed expression of AedaeITP peptide in a number of cells in the brain and in the terminal ganglion. Comparatively, AedaeITP-L peptide was localized solely within the pre-terminal abdominal ganglia of the central nervous system. Interestingly, prolonged desiccation stress caused upregulation of AedaeItp and AedaeItp-l levels in adult mosquitoes, suggesting possible functional roles in water conservation and feeding-related activities. RNAi-mediated knockdown of AedaeItp caused an increase in urine excretion, while knockdown of both AedaeItp and AedaeItp-l reduced blood feeding and egg-laying in females as well as hindered egg viability, suggesting roles in reproductive physiology and behavior. Altogether, this study identifies AedaeITP and AedaeITP-L as key pleiotropic hormones, regulating various critical physiological processes in the disease vector, A. aegypti.

Atypical Clostridium difficile Infection in a Pregnant Patient: A Case Study on Non-Diarrheal Presentation and Syndrome of Inappropriate Antidiuretic Hormone (SIADH) Complication.

Clostridium difficile (C. difficile) is a Gram-positive, spore-producing bacterium that often leads to pseudomembranous colitis, typically manifesting as watery diarrhea. The risk factors for C. difficile infection (CDI) include exposure to broad-spectrum antibiotics, immunocompromised states, advanced age, usage of proton pump inhibitors (PPI), and comorbid conditions such as chronic kidney disease (CKD). This report details a case involving a 23-year-old pregnant woman who presented with symptoms of abdominal pain and constipation. She was diagnosed with a urinary tract infection (UTI) and treated with ceftriaxone. During her hospitalization, she was administered opioid pain relievers and underwent an intensive bowel regimen. Despite these measures, her constipation and abdominal discomfort persisted, and magnetic resonance imaging (MRI) of the abdomen revealed significant dilatation of the large bowel. The patient, discovered to have hyponatremia, underwent further evaluation. This revealed elevated urine osmolality and decreased blood plasma osmolality, indicative of a syndrome of inappropriate antidiuretic hormone secretion (SIADH). The patient received treatment with hypertonic saline. Later in her hospital stay, she tested positive for CDI through stool analysis and was treated with oral vancomycin. This case underscores the importance of considering CDI as a differential diagnosis in cases of ileus, abdominal pain, and constipation, especially in patients with notable risk factors for CDI. It highlights that the presence of diarrhea or watery bowel movements is not a necessary symptom for CDI testing.

Right-sided Herpes Zoster Ophthalmicus Complicated by Bilateral Third, Fourth, and Sixth Cranial Nerve Palsies and Syndrome of Inappropriate Antidiuretic Hormone Secretion: A Case Report.

Cases of herpes zoster ophthalmicus (HZO) complicated by bilateral ophthalmoplegia are rare, and no cases of bilateral third, fourth, or sixth cranial nerve palsies have been reported. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is a rare complication of HZO. We herein report an 80-year-old Japanese woman with right-sided HZO complicated by meningoencephalitis and discuss the pathogenesis of this condition. She developed bilateral third, fourth, and sixth cranial nerve palsies and SIADH almost simultaneously during treatment for HZO. The bilateral cranial palsy spontaneously resolved within a few months.

Symptomatic syndrome of inappropriate anti-diuretic hormone as a rare early presentation of primary thymic carcinoma: a case report.

Syndrome of inappropriate anti-diuretic hormone (SIADH) can be presented as a paraneoplastic syndrome in primary malignancies involving the lung and brain. However, the development of SIADH in primary thymic carcinoma is poorly documented. We report a case of an elderly, with an initial presentation of symptomatic persistent hyponatremia as a paraneoplastic syndrome of SIADH with an incidental finding of anterior mediastinal mass confirmed on imaging. Further investigations are consistent with the diagnosis of poorly differentiated locally advanced thymic carcinoma with lung infiltration (T3N1Mx). The patient underwent an En-bloc total thymectomy and subsequently completed adjuvant chemotherapy and further follow-up showed a complete resolution of hyponatraemic SIADH. In conclusion, SIADH may be presented as a paraneoplastic syndrome in primary thymic carcinoma and early detection of thymic malignancy is paramount to ensure early diagnosis and prognostication.