Hyponatremia is the most common disorder of electrolyte imbalances. It is necessary to develop new type of diuretics to treat hyponatremia without losing electrolytes. Urea transporters (UT) play an important role in the urine concentrating process and have been proved as a novel diuretic target. In this study, rat and mouse syndromes of inappropriate antidiuretic hormone secretion (SIADH) models were constructed and analyzed to determine if UTs are a promising drug target for treating hyponatremia. Experimental results showed that 100 mg/kg UT inhibitor 25a significantly increased serum osmolality (from 249.83 ± 5.95 to 294.33 ± 3.90 mOsm/kg) and serum sodium (from 114 ± 2.07 to 136.67 ± 3.82 mmol/L) respectively in hyponatremia rats by diuresis. Serum chemical examination showed that 25a neither caused another electrolyte imbalance nor influenced the lipid metabolism. Using UT-A1 and UT-B knockout mouse SIADH model, it was found that serum osmolality and serum sodium were lowered much less in UT-A1 knockout mice than in UT-B knockout mice, which suggest UT-A1 is a better therapeutic target than UT-B to treat hyponatremia. This study provides a proof of concept that UT-A1 is a diuretic target for SIADH-induced hyponatremia and UT-A1 inhibitors might be developed into new diuretics to treat hyponatremia.

UNASSIGNED: Hyponatremia is a common electrolyte disorder. The severe hyponatremia has a mortality rate of 4%-40%. Psychiatric patients are likely to develop the condition because of polydipsia or the adverse effects of antipsychotics. We investigated the characteristics of patients with and without psychiatric diseases who developed severe hyponatremia.
UNASSIGNED: We retrospectively investigated cases admitted to our hospital (all departments) between October 2012 and November 2015 with a serum sodium concentration of ≤125 mmol/l on admission. We compared patient characteristics, etiology, and clinical course between psychiatric and nonpsychiatric patients.
UNASSIGNED: In total, 123 cases (62 female) were analyzed. Psychiatric disorders were present in 69 cases (56%), including schizophrenia (n = 19), anorexia (n = 16), mood disorders (n = 14), and organic mental disorders (n = 9). The mean patient age was 63 years. The mean serum sodium concentration on admission was 119 mmol/l, and the main causes of hyponatremia were polydipsia (20%), insufficient sodium intake (18%), and syndrome of inappropriate antidiuretic hormone secretion (16%). Compared with the nonpsychiatric group, the psychiatric group was significantly younger (55 vs. 74 years), was more likely to have polydipsia (30% vs. 6%), and had a lower in-hospital mortality (0% vs. 17%).
UNASSIGNED: Our study found differences in the clinical picture between psychiatric and nonpsychiatric patients with severe hyponatremia. Clinicians need to monitor serum sodium because the symptoms of hyponatremia can mimic those of psychiatric diseases.

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.
CONCLUSIONS: 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.

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.

UNASSIGNED: Immune checkpoint inhibitors (ICI), including Programmed Cell Death 1, Programmed Cell Death Ligand 1, and Cytotoxic T-lymphocyte Associated Antigen 4 inhibitors, upregulate T-cell responses against tumor cells and are becoming a cornerstone in the treatment of various advanced solid and hematological cancers. Mulvihill-Smith Syndrome (MSS) is a rare genetic syndrome that has been associated with metabolic abnormalities and early-onset tumors, including malignancies. We report the first known case of ICI-induced hyponatremia attributable to syndrome of inappropriate antidiuretic hormone ADH release (SIADH) in a patient with MSS.
UNASSIGNED: A 23-year-old female patient with MSS and hepatocellular carcinoma presented with recurrent hyponatremia. Assessment of fluid status and electrolytes revealed a euvolemic, hypotonic process consistent with SIADH shortly after initiating adjuvant therapy with atezolizumab, a Programmed Cell Death Ligand 1 inhibitor.
UNASSIGNED: Endocrine etiologies for euvolemic hypotonic hyponatremia, including adrenal insufficiency and hypothyroidism, were excluded. The diagnosis of SIADH was confirmed based on electrolyte and osmolality studies. Sodium levels normalized with fluid restriction. Given the onset of hyponatremia 30 days after atezolizumab initiation, we posit that atezolizumab triggered severe hyponatremia due to SIADH.
UNASSIGNED: With the expanding utilization of ICIs, including in patients predisposed to malignancies such as MSS, vigilant monitoring for ICI-mediated electrolyte imbalances is crucial. Monitoring for hyponatremia and SIADH in the setting of ICI therapy is recommended.

To optimize clinical care, it is imperative for providers to recognize their own inherent cognitive biases and the impact that has on their clinical decision making, thereby minimizing complications such as prolonged hospitalization, unnecessary healthcare spending, and impaired patient satisfaction and functional outcomes.

UNASSIGNED: Rhinovirus infection has the potential to exhibit unconventional symptoms like symptomatic hyponatremia. Health care professionals should remain vigilant about this potential complication, especially in cases with uncommon presentations. Timely identification and effective management of hyponatremia can mitigate potential complications and enhance patient prognosis.
UNASSIGNED: The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is a prominent contributor to low sodium levels. Various factors can contribute to hyponatremia, affecting the diagnosis and treatment of the condition. Of note, some infections have been identified as potential causes of SIADH. Although rhinovirus infection has been linked to SIADH, it is usually associated with severe respiratory infections. Herein, we present a distinctive case where rhinovirus caused significant hyponatremia symptoms, even in the absence of typical respiratory symptoms or fever.

BACKGROUND: Vortioxetine, known for its efficacy in treating depression through its effects on various neurotransmitters, has not been previously reported to induce syndrome of inappropriate secretion of antidiuretic hormone (SIADH).
METHODS: This case report describes a 74-year-old man with major depressive disorder who developed SIADH 1 week after starting treatment with vortioxetine. SIADH is characterized by symptoms such as headache, nausea, disorientation, and seizures, stemming from hyponatremia (123 mEq/L), without dehydration or edema. Vortioxetine was discontinued, and an alternative drug, mianserin, was initiated. The patient was restricted from drinking water due to hyponatremia. The serum Na concentration improved over time to within the normal range by the second week after admission.
CONCLUSIONS: This is the first case report of vortioxetine-induced SIADH.

Stauffer syndrome is a non-metastatic, nephrogenic, hepatic dysfunction syndrome that is linked to extrahepatic paraneoplastic tumors. It manifests with varying clinical signs that include jaundice, anicteric transaminitis, elevated alkaline phosphatase, thrombocytosis, elevated erythrocyte sedimentation rate, prolonged prothrombin time, and, in some cases, hepatosplenomegaly in the absence of hepatobiliary obstruction. Stauffer syndrome is mostly associated with renal cell carcinoma, but research shows other solid malignancies are implicated with this syndrome. Stauffer syndrome is characterized by elevated liver function tests, specifically those that indicate the presence of cholestasis with or without hepatosplenomegaly. The abnormality is not due to tumor infiltration but rather indirect paraneoplastic effects that are poorly understood. Additionally, emerging literature also supports the association of syndrome of inappropriate antidiuretic hormone secretion (SIADH) secondary to malignancy in the setting of elevated interleukin-6. In this article, we present the case of a 76-year-old patient with SIADH and abnormalities in liver function tests in the context of Stauffer syndrome tied to renal cell carcinoma coinciding with liposarcoma.

Tuberculous meningitis (TBM) is a severe form of extrapulmonary tuberculosis (TB) characterized by the invasion of Mycobacterium tuberculosis into the meninges surrounding the brain and spinal cord. It triggers an intense inflammatory response, leading to neurological complications if not promptly and adequately managed. TBM often precipitates muscle weakness, neurological deficits, respiratory challenges, swallowing difficulties, joint contractures, and pain. Physiotherapy intervention is essential in treating these problems by personalized treatment strategies and treatment plans to enhance muscle strength, motor control, coordination, and overall mobility. This case report aims to highlight the significant role of physiotherapy in improving the quality of life (QOL) and functional abilities of patients with TBM. The current case report reviews the case of a 73-year-old male who presented with complaints of generalized weakness and difficulty in swallowing. The patient had a history of fever for the last six months. Magnetic resonance imaging (MRI) and high-resolution computed tomography (HRCT) diagnosed the case as TBM with miliary TB. Six weeks of targeted intensive rehabilitation program was designed according to the patient\'s impairments initiated from the intensive care unit (ICU) phase. The main goals of physiotherapy were to start early bed mobility, maintain joint integrity, improve postural strength and swallowing, and make the patient independent in transfer and activities of daily living (ADLs). After a six-week intensive physiotherapy (TIP-6) program, the patient exhibited significant improvements in muscle strength and independence in ADLs. This case highlights the critical role of physiotherapy in enhancing the QOL and functional abilities of patients with severe TB-related conditions.