Inappropriate Antidiuretic Hormone Secretion and Cerebral Salt-Wasting Syndromes in Neurological Patients

[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.

Risk factors and outcome of hyponatremia in patients with Guillain-Barré syndrome

The objective of the present study was to evaluate the risk factors and outcomes associated with hyponatremia in patients with Guillain-Barré syndrome (GBS). We retrospectively studied 80 consecutive patients with GBS who visited our hospital and compared clinical, laboratory, and electrophysiological findings of patients with and without hyponatremia. Disability was evaluated using the Hughes grading system. Of the 80 patients, 18 (23%) had hyponatremia. Hyponatremia was significantly associated with older age (P = 0.003), urinary retention (P < 0.0001), Hughes grade ≥ 4 at admission and nadir (P = 0.003 and P < 0.001, respectively), acute inflammatory demyelinating polyneuropathy subtype (P = 0.017), sepsis (P = 0.001), mechanical ventilator support (P = 0.013), longer hospitalization length of stay (P < 0.0001), and inability to walk independently at 6 months (P < 0.001). Multivariate analysis performed to assess the risk factors of hyponatremia revealed that urinary retention (odds ratio [OR] 30.7, 95% confidence interval [CI] 3.6-264.4; P = 0.002) and mechanical ventilator support (OR 13.8, 95% CI 1.6-118.0; P = 0.017) were significant independent risk factors of hyponatremia. In assessing the outcomes of patients with hyponatremia, multivariate analysis showed that hyponatremia was independently associated with hospitalization length of stay ≥ 60 days and inability to walk independently at 6 month, with the former showing statistical significance but the latter not (OR 9.3, 95% CI 1.8-47.7; P = 0.007 and OR 4.9, 95% CI 0.9-26.3; P = 0.066, respectively). Therefore, we demonstrate that, along with mechanical ventilator support, urinary retention-possibly indicating autonomic dysfunction-is a risk factor of hyponatremia in GBS. Moreover, we confirm that hyponatremia is associated with poor outcome in GBS.

The Never-Ending Story of Hyponatremia: A Current Problem to Overcome

Hyponatremia is a common complication in patients undergoing neurosurgery. If undiagnosed, it has a negative prognostic impact. The two dominant causes of refractory hyponatremia include syndrome of inappropriate ADH secretion (SIADH) and cerebral salt wasting syndrome (CSWS). Discrimination between the two types of disease is not always obvious. We present a case of undiagnosed chronic hyponatremia caused by CSWS after neurosurgery, which not only resulted in a longer hospital stay but also slowed the patient's postoperative recovery. Meticulous clinical evaluation and the performance of appropriate laboratory tests are therefore essential not only for decisive treatment, but also for the establishment of comprehensive diagnostic algorithms that allow timely diagnosis and decisive therapy.

LEARNING POINTS

The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) and cerebral salt-wasting syndrome (CSWS) are in general associated to refractory hyponatremia especially in patients with neurologic disorders.Extracellular fluid (ECF) assessment is the key to distinguish between SIADH and CSWS.Nevertheless, measurement of the ECF volume is not sufficient to determine the correct etiology and more established diagnostic algorithms are required.

Pre-thrombolysis serum sodium concentration is associated with post-thrombolysis symptomatic intracranial hemorrhage in ischemic stroke patients

Background and aim

Symptomatic intracranial hemorrhage (sICH) was the most serious complication associated with alteplase intravenous thrombolysis (IVT) in acute ischemic stroke (AIS) patients. However, the relationship between serum sodium levels and post-thrombolysis symptomatic intracranial hemorrhage has not been investigated. Therefore, the aim of this study was to investigate the relationship between pre-thrombolysis serum sodium levels and sICH after IVT, as well as to explore the optimal pre-thrombolysis serum sodium levels for lowering the risk of sICH following IVT.

Methods

From July 1, 2017 to April 30, 2023, out-of-hospital AIS patients who received IVT in the emergency department were enrolled in this study. Serum sodium levels were measured at admission prior to IVT, and National Institutes of Health Stroke Scale scores were continuously assessed during and after thrombolysis. Routine follow-up neuroimaging was performed between 22 to 36 h after IVT. Initially, three logistic regression models and restricted cubic splines (RCS) were established to investigate the relationship between serum sodium levels and post-thrombolysis sICH. Furthermore, to evaluate the predictive value of serum sodium for post-thrombolysis sICH, we compared area under the receiver operating characteristic curve (AUROC) and net reclassification improvement (NRI) before and after incorporating serum sodium into traditional models. Finally, subgroup analysis was conducted to explore interactions between serum sodium levels and other variables.

Results

A total of 784 AIS patients who underwent IVT were enrolled, among whom 47 (6.0%) experienced sICH. The median serum sodium concentration for all patients was 139.10 [interquartile ranges (IQR): 137.40-141.00] mmol/L. Patients who developed sICH had lower serum sodium levels than those without sICH [138.20(IQR:136.00-140.20) vs. 139.20(IQR:137.40-141.00), p = 0.031]. Logistic regression analysis (model 3) revealed a 14% reduction in the risk of post-thrombolysis sICH for every 1 mmol/L increase in serum sodium levels after adjusting for confounding variables (p < 0.001). The risk of post-thrombolysis sICH was minimized within the serum sodium range of 139.1-140.9 mmol/L compared to serum sodium concentration below 137.0 mmol/L [odds ratio (OR) = 0.33, 95% confidence interval (CI): 0.13-0.81] in model3. Furthermore, there was a significant trend of decreasing risk for sICH as serum sodium concentrations increased across the four quartiles (P for trend = 0.036). The RCS analysis indicated a statistically significant reduction in the risk of sICH as serum sodium levels increased when the concentration was below 139.1 mmol/L. Incorporating serum sodium into traditional models improved their predictive performance, resulting in higher AUROC and NRI values. Subgroup analysis suggested that early infarct signs (EIS) appeared to moderate the relationship between serum sodium and sICH (p < 0.05).

Conclusion

Lower serum sodium levels were identified as independent risk factors for post-thrombolysis sICH. Maintaining pre-thrombolysis serum sodium concentrations above 139.1 mmol/L may help reduce the risk of post-thrombolysis sICH.

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.

Hyponatremia in Guillain-Barre Syndrome: A Review of Its Pathophysiology and Management

Guillain-Barre syndrome (GBS) is the commonest cause of acute polyradiculoneuropathy that requires hospitalization. Many of these patients experience systemic and disease-related complications during its course. Notable among them is hyponatremia. Though recognized for decades, the precise incidence, prevalence, and mechanism of hyponatremia in GBS are not well known. Hyponatremia in GBS patients is associated with more severe in-hospital disease course, prolonged hospitalization, higher mortality, increased costs, and a greater number of other complications in the hospital and worse functional status at 6 months and at 1 year. Though there are several reports of low sodium associated with GBS, many have not included the exact temporal relationship of sodium or its serial values during GBS thereby underestimating the exact incidence, prevalence, and magnitude of the problem. Early detection, close monitoring, and better understanding of the pathophysiology of hyponatremia have therapeutic implications. We review the complexities of the relationship between hyponatremia and GBS with regard to its pathophysiology and treatment.

Predictive value of hyponatremia for short-term mortality in supratentorial spontaneous intracerebral hemorrhage: a single center study

Background

Hyponatremia is a common electrolyte disturbance in patients with neurological disease; however, its predictive role for outcome in patients with supratentorial spontaneous intracerebral hemorrhage (sICH) is controversial. This study aims to explore the association between hyponatremia within 7 days after bleeding and 90-day mortality in patients with supratentorial sICH.

Methods

A retrospective analysis was conducted at our institution. Patients with sICH meeting the inclusion criteria were enrolled in this study. Multivariate regression analyses were performed to determine the predictive value of hyponatremia (serum sodium <135 mmol/L) for 90-day mortality and functional outcome. Subgroup analysis was performed based on the degree and duration of hyponatremia and therapeutic strategies. The Spearman correlation test was performed to explore the relationship between hyponatremia severity and duration with variables in a multivariate regression model. Kaplan-Meier curve was depicted to reveal the relationship between hyponatremia and mortality. The receiver operating characteristic (ROC) curve was plotted to show the diagnostic effect of the minimum concentration of serum sodium (sodiummin) on 90-day mortality.

Results

A total of 960 patients were enrolled, 19.6% (188) of whom were patients with hyponatremia and 26.0% (250) had 90-day mortality. The incidence of hyponatremia was roughly 2.5 times in non-survivors compared with survivors (34.8% vs. 14.2%). Multivariate regression analysis revealed that hyponatremia was the independent predictor of 90-day mortality (OR 2.763, 95%CI 1.836-4.157) and adverse outcome (OR 3.579, 95%CI 2.332-6.780). Subgroup analysis indicated an increased trend in mortality risk with both duration (more or less than 48 h) and severity of hyponatremia (mild, moderate, and severe) and confirmed the predictive value of hyponatremia for mortality in patients undergoing surgical intervention (external ventricular drainage, craniotomy, and decompressive craniectomy; all p < 0.05). The Spearman correlation test indicated no moderate or strong relationship between hyponatremia severity and duration with other variables in the multivariate model (all |rs| < 0.4). The ROC curve suggested the moderate diagnostic performance of sodiummin for mortality in both general patients and subgroups of therapeutic method patients (AUC from 0.6475 to 0.7384).

Conclusion

Hyponatremia occurring in the first 7 days after bleeding is an independent predictor of 90-day morality and adverse outcome. Rigorous electrolyte scrutiny in patients treated surgically is required.

Hashimoto Encephalopathy Presenting with Acute Psychosis and Inappropriate Secretion of Antidiuretic Hormone: A Rare Case Responding to Steroid Therapy

BACKGROUND Hashimoto's encephalopathy (HE) is an autoimmune encephalopathy that can involve various symptoms including psychosis. Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) may be a complication in some neurological diseases. However, the simultaneous occurrence of subacute psychosis and SIADH as the manifestation of HE, observed in the present case, has rarely been reported. CASE REPORT A 72-year-old man was hospitalized with a 4-month history of abnormal behaviors, including talkativeness, stopping consumption of coffee and cigarettes, hoarding garbage, and sleep disorders. On physical examination, increased and incoherent speech with flight of idea and delusion were observed. The Mini-Mental State Examination score was 28/30. Laboratory findings included hyponatremia due to SIADH and a positive result for anti-thyroid and anti-NH2 terminal of alpha-enolase antibodies. Cerebrospinal fluid examination revealed only elevation of IL-6. Brain magnetic resonance imaging was unremarkable; however, (I-123)-iodoamphetamine single-photon emission computed tomography showed extensive hyperperfusion involving the brainstem and bilateral frontal and medial temporal lobes. Electroencephalography showed generalized slow waves, but there were no epileptiform discharges. After 2 courses of high-dose intravenous methylprednisolone followed by oral prednisolone, his symptoms improved. Based on the findings of clinical features and steroid responsiveness, he was diagnosed with HE. Oral prednisolone and antipsychotic drugs were decreased without a relapse and he was discharged to his home. CONCLUSIONS Although psychosis complicating SIADH is rare, HE should be considered in the differential diagnosis because of its treatment efficacy.

Cerebral Salt Wasting Syndrome in the Setting of Hypovolemic Isotonic Hyponatremia: A Case Report

Cerebral salt wasting syndrome (CSWS) is a condition characterized as the loss of sodium secondarily due to an intracranial process, commonly following the neurosurgical resection of mass lesions. This condition leads to a hypovolemic hypotonic hyponatremia. The identification of this syndrome is often mistaken for syndrome of inappropriate anti-diuretic hormone (SIADH). The treatment for both conditions is vastly different. Given the risk of mortality when balancing sensitivities in hyponatremia and its commonality in clinical scenarios, a distinction is crucial. In this case report, we discuss a patient who presented with CSWS following the surgical resection of a pituitary adenoma. She subsequently developed hypernatremia, treated with DDAVP for the suspicion of diabetes insipidus. Once this was discontinued, she further presented with worsening hyponatremia. This hyponatremia persisted even after the discontinuation of DDAVP, with no significant intervention leading to hypovolemic isotonic hyponatremia, supporting a diagnosis of CSWS. Our findings stress the importance of the proper identification of hyponatremia with guided treatment following neurosurgical intervention and give physicians an insight into the anomalies of hyponatremia that should be further discussed.

Mechanisms of hyponatremia and diabetes insipidus after acute spinal cord injury: a critical review

The incidence of hyponatremia after spinal cord injury was reported to be between 25 and 80%. Hyponatremia can lead to a variety of clinical symptoms, from mild to severe and even life-threatening. Hyponatremia is often associated with diabetes insipidus, which refers to insufficient arginine vasopressin (AVP) secretion or defective renal response to AVP, with clinical manifestations of syndromes such as hypoosmolality, polydipsia, and polydipsia. Recent mechanistic studies on hyponatremia and diabetes insipidus after acute spinal cord injury have been performed in isolation, without integrating the above two symptoms into different pathological manifestations that occur in the same injury state and without considering the acute spinal cord injury patient's condition as a whole. The therapeutic principles of CSWS and SIADH are in opposition to one another. It is not easy to identify the mechanism of hyponatremia in clinical practice, which makes selecting the treatment difficult. According to the existing theories, treatments for hyponatremia and diabetes insipidus together are contraindicated, whether the mechanism of hyponatremia is thought to be CSWS or SIADH. In this paper, we review the mechanism of these two pathological manifestations and suggest that our current understanding of the mechanisms of hyponatremia and diabetes insipidus after high acute cervical SCI is insufficient, and it is likely that there are other undetected pathogenetic mechanisms.

The Spectrum of Headache in Leptomeningeal Metastases: A Comprehensive Review with Clinical Management Guidelines

PURPOSE OF REVIEW

Headaches are a common, oftentimes debilitating symptom in patients with leptomeningeal metastases.

RECENT FINDINGS

The third edition of the International Classification of Headache Disorders provides a useful diagnostic framework for headaches secondary to leptomeningeal metastases based on the temporal relationship of headache with disease onset, change in headache severity in correlation with leptomeningeal disease burden, and accompanying neurologic signs such as cranial nerve palsies and encephalopathy. However, headaches in patients with leptomeningeal metastases can be further defined by a wide range of varying cancer- and treatment-related pathophysiologies, each requiring a tailored approach. A thorough review of the literature and expert opinion on five observed headache sub-classifications in patients with leptomeningeal metastases is provided, with attention to necessary diagnostic testing, recommended first-line treatments, and prevention strategies.

Suspected medullary washout leading to severe polyuria following delayed cerebral ischemia: a case report

BACKGROUND

Delayed cerebral ischemia is a clinical entity commonly encountered in patients presenting with acute neurological injury and is often complicated by dysnatremias, such as the cerebral salt wasting syndrome. In this case report, we described an exceptional case of polyuria attributed to an initial cerebral salt wasting phenomenon and iatrogenic-induced medullary washout.

CASE PRESENTATION

A 53-year-old woman was admitted to our hospital for the management of a Modified Fisher scale grade 4 subarachnoid hemorrhage due to a ruptured posterior communicating aneurysm. She was initially managed with coil embolization and external ventricular drain due to secondary hydrocephalus. Throughout the course of her hospitalization, she developed severe polyuria reaching up to 40L per day. To keep up with the excessive urinary losses and maintain appropriate cerebral perfusion, fluid replacement therapy was adjusted every hour, reaching up to 1.3 L of crystalloid per hour in addition to aminergic support. An initial diagnosis of partial diabetes insipidus, followed by a cerebral salt wasting syndrome was suspected. While the urine output continued to increase, her serum urea concentration progressively decreased to a point of almost being undetectable on day 9. At that time, the presence of an interstitial medulla washout was hypothesized. Various pharmacological and non-pharmacological interventions were progressively introduced to regain normal renal homeostasis, including non-steroidal anti-inflammatory drugs, fludrocortisone, oral urea and high-protein intake. Medications were progressively weaned, and the patient was successfully discharged from the ICU.

CONCLUSIONS

Cerebral salt wasting should be considered in the initial differential diagnosis of a patient presenting with polyuria in the context of acute neurological injury. Early recognition of this entity is critical to quickly implement proper management. However, as shown in this case report, the concomitance of delayed cerebral ischemia may complexify that management.

Prevention and Correction of Dysnatremia After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Dysnatremia occurs commonly in patients with aneurysmal subarachnoid hemorrhage (aSAH). The mechanisms for development of sodium dyshomeostasis are complex, including the cerebral salt-wasting syndrome, the syndrome of inappropriate secretion of antidiuretic hormone, diabetes insipidus. Iatrogenic occurrence of altered sodium levels plays a role, as sodium homeostasis is tightly linked to fluid and volume management.

METHODS

Narrative review of the literature.

RESULTS

Many studies have aimed to identify factors predictive of the development of dysnatremia, but data on associations between dysnatremia and demographic and clinical variables are variable. Furthermore, although a clear relationship between serum sodium serum concentrations and outcomes has not been established-poor outcomes have been associated with both hyponatremia and hypernatremia in the immediate period following aSAH and set the basis for seeking interventions to correct dysnatremia. While sodium supplementation and mineralocorticoids are frequently administered to prevent or counter natriuresis and hyponatremia, evidence to date is insufficient to gauge the effect of such treatment on outcomes.

CONCLUSIONS

In this article, we reviewed available data and provide a practical interpretation of these data as a complement to the newly issued guidelines for management of aSAH. Gaps in knowledge and future directions are discussed.

Cerebral Salt Wasting Syndrome Following Right Occipital Craniotomy in a Patient With Metastatic Lung Adenocarcinoma

Cerebral salt wasting syndrome (CSW) is characterized by excessive natriuresis leading to hyponatremia and hypovolemia. It is commonly encountered among patients who have undergone brain trauma or subarachnoid hemorrhage. The occurrence of CSW after neurosurgical procedures has been frequently reported in the pediatric age group; however, it is a rare phenomenon in adults. We describe the case of a 59-year-old female who developed symptoms of polyuria and polydipsia after a right occipital craniotomy.

Suspected Cerebral Salt Wasting Syndrome with Cervical Spinal Lesion in a Domestic Shorthair Cat

A 12-year-old spayed female domestic short cat was presented with tetraplegia. The cat also showed signs of hyponatremia and dehydration, which were rapidly corrected by intravenous fluid infusion. Based on thorough physical and neurological examinations, the patient was suspected of having an intracranial disease. MRI revealed a high-signal T2 image of the bilateral parietal cerebral cortical gray matter junction, which is associated with fast electrolyte calibration, and a high-signal T2 image of the C2 spinal cord ventral area, which is associated with ischemic myelopathy. The cat reappeared three days later due to anorexia. Laboratory examinations revealed that the cat was clinically dehydrated and exhibited hyponatremia. Other causes of hyponatremia were excluded through history-taking, laboratory examination, imaging, and therapeutic response to fluid therapy, except for cerebral salt-wasting syndrome (CSWS). The cat was discharged 3 days after the start of fludrocortisone therapy with electrolytes within the normal range. Magnetic resonance imaging (MRI) was performed again 1 month after hospitalization, and the cerebral lesion disappeared, but the spinal cord lesion worsened compared to the previous image. The patient was euthanized due to the progression of the spinal lesion, with a poor prognosis and poor quality of life. This is the first case of suspected CSWS with a cervical spinal lesion in a cat.

Hyponatremia after craniotomy in children: a single-institution review

PURPOSE

Hyponatremia after craniotomy can be associated with increased morbidity. However, the incidence of and factors associated with post-craniotomy hyponatremia in children are not known.

METHODS

We performed a retrospective cohort study of patients aged 0-21 years who underwent craniotomy in 2017-2019 at a single center to determine the incidence of and to identify risk factors for hyponatremia after craniotomy. Indications for craniotomy included tumors (excluding craniopharyngioma), epilepsy, intracranial infection, trauma, craniofacial, suboccipital decompression for the treatment of Chiari malformation, and cerebrovascular disease. Hyponatremia was defined as a serum sodium level ≤ 135 mEq/L any time during the postoperative hospital stay. Statistical significance was defined a priori at p < 0.05.

RESULTS

Postoperative hyponatremia occurred in 61 (25%) of 240 children. On univariate analysis, hyponatremia was associated with younger age (8.5 vs 6.3 years, p = 0.01), use of preoperative anti-epileptic drugs (p = 0.02), need for blood transfusion (p = 0.02), government/private insurance (p = 0.04), and pre-existing hydrocephalus, defined as the requirement for permanent cerebrospinal fluid (CSF) diversion (p = 0.04). On multivariate analysis, only hydrocephalus (OR 2.95, 95% CI 1.03-8.40) remained statistically significant. Hyponatremia most occurred on the first postoperative day, with normonatremia achieved in a median of 14 (IQR 9.8-24.3) h. Hyponatremia was significantly associated with longer length of stay (median 8 vs 3 days, p < 0.01).

CONCLUSION

Hyponatremia was present in 25% of children after craniotomy. Preoperative hydrocephalus as an independent risk factor for hyponatremia after craniotomy.

Clinical and pathophysiological aspects of impaired water and sodium metabolism in newborns and neurological complication

This literature review covers the pathophysiological features of water and sodium exchange in newborns. The main mechanisms regulating fluid and electrolyte balance in newborns are poorly studied. The volume and composition of the extracellular fluid are provided by the functional activity of the kidneys under the control of the neuroendocrine system. The antidiuretic hormone plays the main role in the regulation of water excretion by the kidneys. The volume of intracellular fluid depends on the passive water transport with the participation of aquaporins. Lability of water and electrolyte metabolism in newborns may be accompanied by hyponatremia. For various pathological conditions in the neonatal period, certain types of hyponatremias are characteristic. Correction of hyponatremia should be carried out taking into account its pathophysiological type. Hyponatremia is a common complication associated with severe neonatal brain damage. Hyponatremia contributes to brain damage as an independent factor. The study of indicators of water and electrolyte balance in the neonatal period has an important prognostic value for early detection of damage to the central nervous system.

A step-by-step guide for the diagnosis and management of hyponatraemia in patients with stroke

Hyponatraemia is common in patients with stroke and associated with adverse outcomes and increased mortality risk. The present review presents the underlying causes and provides a thorough algorithm for the diagnosis and management of hyponatraemia in stroke patients. Concomitant diseases and therapies, such as diabetes, chronic kidney disease and heart failure, along with diuretics, antidepressants and proton pump inhibitors are the most common causes of hyponatraemia in community. In the setting of acute stroke, the emergence of hyponatraemia might be attributed to the administration of hypotonic solutions and drugs (ie. mannitol and antiepileptics), poor solute intake, infections, as well as stroke-related conditions or complications, such as the syndrome of inappropriate secretion of antidiuretic hormone, cerebral salt wasting syndrome and secondary adrenal insufficiency. Diagnostically, the initial step is to differentiate hypotonic from non-hypotonic hyponatraemia, usually caused by hyperglycaemia or recent mannitol administration in patients with stroke. Determining urine osmolality, urine sodium level and volume status are the following steps in the differentiation of hypotonic hyponatraemia. Of note, specific parameters, such as fractional uric acid and urea excretion, along with plasma copeptin concentration, may further improve the diagnostic yield. Therapeutic options are based on the duration and symptoms of hyponatremia. In the case of acute or symptomatic hyponatraemia, hypertonic saline administration is recommended. Hypovolaemic chronic hyponatremia is treated with isotonic solution administration. Although fluid restriction remains the first-line treatment for the rest forms of chronic hyponatraemia, therapies increasing renal free water excretion may be necessary. Loop diuretics and urea serve this purpose in patients with stroke, whereas sodium-glucose transport protein-2 inhibitors appear to be a promising therapy. Nevertheless, it is yet unclear whether the appropriate restoration of sodium level improves outcomes in such patients. Randomized trials designed to compare therapeutic strategies in managing hyponatraemia in patients with stroke are required.

Cerebral Salt Wasting Syndrome Associated with Status Epilepticus

Cerebral salt wasting syndrome (CSWS) is defined as a renal loss of sodium in cerebral disorders causing hyponatremia and loss of extracellular fluid volume. Similar laboratory findings may be seen in other conditions such as syndrome of inappropriate antidiuretic hormone secretion (SIADH). A 58-year-old male visited our emergency department because of the sudden development of seizures during sleep. Magnetic resonance imaging revealed subtle high signal intensity in the right hippocampus on diffusion-weighted imaging. Ictal rhythmic discharges were observed in the concordant area. Altered metal status, polyuria and laboratory test findings including hyponatremia were compatible with CSWS. After hydration and salt replacement, his mental state and hyponatremia gradually recovered. For diagnosing CSWS, meticulous physical examinations including analysis of fluid balance are essential. CSWS should be considered in patients with hyponatremia and polyuria. Accurate diagnosis of CSWS and SIADH is crucial as the treatment plans for these two conditions are completely different.

Changes in Serum Creatinine Levels Can Help Distinguish Hypovolemic from Euvolemic Hyponatremia

Background and Objectives: Differentiating between hypovolemic (HH) and euvolemic hyponatremia (EH) is crucial for correct diagnosis and therapy, but can be a challenge. We aim to ascertain whether changes in serum creatinine (SC) can be helpful in distinguishing HH from EH. Materials and Methods: Retrospective analysis of patients followed in a monographic hyponatremia outpatient clinic of a tertiary hospital during 1 January 2014−30 November 2019. SC changes during HH and EH from eunatremia were studied. The diagnostic accuracy of the SC change from eunatremia to hyponatremia (∆SC) was analyzed. Results: A total of 122 hyponatremic patients, median age 79 years (70−85), 46.7% women. In total, 70/122 patients had EH, 52/122 HH. During hyponatremia, median SC levels increased in the HH group: +0.18 mg/dL [0.09−0.39, p < 0.001], but decreased in the EH group: −0.07 mg/dL (−0.15−0.02, p < 0.001), as compared to SC in eunatremia. HH subjects presented a higher rate of a positive ∆SC than EH (90.4% vs. 25.7%, p < 0.001). EH subjects presented a higher rate of a negative/null ∆SC than HH (74.3% vs. 9.6%, p < 0.001). ROC curve analysis found an AUC of 0.908 (95%CI: 0.853 to 0.962, p < 0.001) for ∆SC%. A ∆SC% ≥ 10% had an OR of 29.0 (95%CI: 10.3 to 81.7, p < 0.001) for HH. A ∆SC% ≤ 3% had an OR of 68.3 (95%CI: 13.0 to 262.2, p < 0.001) for EH. Conclusions: The assessment of SC changes from eunatremia to hyponatremia can be useful in distinguishing between HH and EH.

Syndrome of inappropriate secretion of antidiuretic hormone as an initial sign of primary central nervous system lymphomas in the hypothalamus

BACKGROUND

Primary central nervous system lymphoma (PCNSL) rarely originates in the hypothalamus. Hypothalamic PCNSL can present with various symptoms specific to dysfunction of the hypothalamus, including consciousness disturbance, cognitive impairment, hypopituitarism, and diabetes insipidus (DI). However, it remains unclear whether syndrome of inappropriate secretion of antidiuretic hormone (SIADH) can present as an initial sign of hypothalamic PCNSL.

METHODS

Ninety-nine patients with PCNSL were diagnosed between January 2006 and December 2020 at our institutes. The initial symptoms and signs, hypothalamic-pituitary functions, serum sodium (Na) value, Karnofsky Performance Status (KPS) score on admission, and duration from onset to diagnosis were retrospectively investigated from the medical charts.

RESULTS

Eight and 91 patients had hypothalamic PCNSL (hypothalamic group) and PCNSL located in other regions (control group), respectively. Patients' pathological diagnoses were diffuse large B-cell lymphoma (97 patients) and intravascular lymphoma (two patients). Six patients presented with hyponatremia derived from SIADH or suspected SIADH, and one presented with DI. Statistically significant differences between the hypothalamic and control groups were detected only in the preoperative serum Na values and KPS scores.

CONCLUSION

SIADH can be an initial presentation of hypothalamic PCNSL. Early detection of hypothalamic PCNSL from SIADH may lead to proper management and improved prognosis.

High Urinary Sodium Concentrations in Severe SIADH: Case Reports of 2 Patients and Literature Review

We present two cases of severe hyponatremia secondary to syndrome of inappropriate secretion of antidiuretic hormone (SIADH) with very high urine sodium concentrations (>130 mmol/L). The first patient had hyponatremia from traumatic brain injury (TBI) while the second case had a history of recurrent SIADH triggered by various causes including gastritis. In both cases, fluid administration and/or consumption worsened the hyponatremia. Although a low urine sodium of <30 mmol/L is highly suggestive of hypovolemic hyponatremia and good response to saline infusion, there is lack of clarity of the threshold of which high urine sodium concentration can differentiate various causes of natriuresis such as SIADH, renal or cerebral salt wasting. Apart from high urine osmolality (>500 mOsm/kg), persistence of high urine sodium concentrations may be useful to predict poor response to fluid restriction in SIADH. More studies are needed to delineate treatment pathways of patients with very high urine osmolality and urine sodium concentrations in SIADH.

Effect of Cerebral Ischemic Strokes in Different Cerebral Artery Regions on Left Ventricular Function

Objectives

The relationship between cerebral ischemic stroke and left ventricular function evaluated by echocardiography has been emphasized. Whether lesions in different cerebral artery regions would result in left ventricular dysfunction remains uncertain.

Methods

Patients were divided into middle cerebral artery (MCA) (n = 79), posterior cerebral artery (PCA) (n = 64), basilar artery (BA) regions (n = 66), and no-ischemic stroke group (n = 209). We retrospectively collected demographic characteristics, hematologic parameters, and ECG results, and a comparison of echocardiographic parameters was performed to determine the relationship between ischemic stroke and left ventricular function.

Results

A total of 418 patients were included. Demographic characteristics did not significantly differ between the ischemic stroke and non-ischemic stroke groups, except for a history of drinking (p &lt; 0.001). Homocysteine levels in the MCA group were higher than those in the PCA and BA groups (p &lt; 0.05). The highly sensitive C-reactive protein (hs-CRP) level was higher in the ischemic stroke group than in the non-ischemic stroke one (p = 0.001). A higher incidence of ST-T changes in the ECG and lower levels of potassium and magnesium in the ischemic stroke group were found. Significant differences in diastolic function between groups were noted, and the early mitral inflow velocity, annular early diastolic velocity, and ratio between the mitral annular early diastolic velocity and mitral annulus atrial inflow velocity in the MCA group were lower than those in the BA group (p &lt; 0.05).

Conclusions

Ischemic strokes exhibited a negative effect on left ventricular diastolic function by echocardiography, especially in MCA region infarcts. These results are of great importance for neurologists as they highlight the need for left ventricular function evaluation after stroke to regulate therapy strategies in time.

Cerebral Salt Wasting Syndrome (CSW): An unusual cause of hypovolemia after spontaneous cerebral hemorrhage successfully treated with fludrocortisone

Our objective is to demonstrate the interest of thinking about Cerebral salt wasting syndrome (CSW) in front of hyponatremia with severe hypovolemia after a brain injury, and at the same time the interest to differentiate between Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) and Cerebral salt wasting syndrome (CSW) as two etiologies to be evoked in front of a hyponatremia with brain injury.

Case report: We report the case of a 63-year-old patient with a recent history of hemorrhagic stroke admitted for severe hypovolemic shock in whom the investigations find a very deep hypotonic hyponatremia secondary to a cerebral salt wasting syndrome successfully treated with fludrocortisone.

Discussion: CWS is characterized by hypotonic hyponatremia associated with cerebral associated with hypovolemia, the difficulty of the diagnosis is explained by the points of convergences with SIADH which is also presented with hyponatremia. The treatment is based on filling with saline, if the symptoms are severe, hypertonic saline has its place. Fludrocortisone has proven its effectiveness in the correction of refractory hyponatremia in CWS.

Conclusion: It is essential to differentiate between hyponatremia in CWS and hyponatremia in SIADH because the medical care is categorically different.

Clinical case of combined diabetes insipidus and cerebral salt-wasting syndrome in a patient with craniocerebral and spinal injury

Introduction. Cerebral salt-wasting syndrome and diabetes insipidus are serious complications of craniocerebral injury and spinal cord injuries. Each of the syndromes in some cases causes a life-threatening condition. This determines the importance of timely diagnosis and emergency intensive care measures. In the literature, there are only single descriptions of combinations of these symptoms in one patient.Clinical case report. A victim with craniocerebral injury and cervical spinal cord injury underwent, according to emergency indications, emptying and drainage of a tense subgaleal hematoma of the fronto-parieto-occipital region, spinal cord decompression, and stabilization of the spine. Postoperative follow-up and intensive care: on the 1st day the rate of diuresis was 2.5 mL/kg/h, blood glucose level – 14.18 mmol/L, and sodium level – 148–158 mmol/L. The patient was diagnosed with diabetes insipidus, and a therapy with desmopressin at a dose of 0.6 mg/day, restoration of fluid volume with hypotonic solutions, and correction of hyperglycemia was started. On the 4th day blood sodium level was 133 mmol/L, and blood glucose level – 8.67 mmol/L. On the 5th day, hyponatremia of 126–115 mmol/L was noted with a diuresis rate of 4 mL/kg/h and glicemya level of 7.86 mmol/L. The development of cerebral salt-wasting syndrome was diagnosed, and the infusion of hydrocortisone 400 mg/day and of 10% NaCl solution was started. On the 6th day glucose level returned to normal. On the 9th day of follow-up, an increase in the volume of diuresis was again observed, and desmopressin therapy was continued. Stable normalization of water-electrolyte balance, urine output, and glucose levels were observed on the 16th day of follow-up.Conclusion. Monitoring of fluid balance and electrolyte composition of blood serum, and adequate replacement therapy were the conditions for successful treatment of a rare combination of diabetes insipidus and cerebral salt-wasting syndrome in patients with concomitant craniocerebral and spinal cord injuries.

Sodium Levels Predict Disability at Discharge in Guillain-Barré Syndrome: A Retrospective Cohort Study

Guillain-Barré syndrome (GBS) is an inflammatory polyradiculopathy with potentially severe complications. Clinical tools for risk stratification have been developed, but no definitive prognostic biomarker has been reported. Hyponatremia is frequent in GBS patients, but the impact of serum sodium levels on clinical outcomes is still ill-defined. In this retrospective cohort study, we included all adult patients diagnosed with GBS spectrum disorders at our center from January 2010 to July 2020. Disability at discharge was assessed with the GBS Disability Score (GDS), and all clinical and laboratory data was retrieved from medical charts. Thirty (58.8%) of the 51 subjects included in the study were discharged with severe residual disability (GDS ≥ 3). After accounting for relevant confounders, the odds of experiencing severe disability decreased by 27% (p = 0.027) for each unitary increase in serum sodium concentration. Thirteen (25.5%) patients were diagnosed with mild to moderate hyponatremia; the use of intravenous immune globulin (IVIG) independently increased the odds of developing hyponatremia. In conclusion, we found a significant, independent association between baseline serum sodium levels and severe disability at discharge in GBS patients. In our cohort, hyponatremia was more frequently observed after treatment with IVIG, suggesting dilutional pseudohyponatremia as a probable cause.

Serum Sodium Concentration and Mental Status in Children With Diabetic Ketoacidosis

OBJECTIVES

Diabetic ketoacidosis (DKA) is typically characterized by low or low-normal serum sodium concentrations, which rise as hyperglycemia resolves. In retrospective studies, researchers found associations between declines in sodium concentrations during DKA and cerebral injury. We prospectively investigated determinants of sodium concentration changes and associations with mental status alterations during DKA.

METHODS

Using data from the Pediatric Emergency Care Applied Research Network Fluid Therapies Under Investigation in Diabetic Ketoacidosis Trial, we compared children who had declines in glucose-corrected sodium concentrations with those who had rising or stable concentrations. Children were randomly assigned to 1 of 4 intravenous fluid protocols that differed in infusion rate and sodium content. Data from the first 4, 8, and 12 hours of treatment were analyzed for 1251, 1086, and 877 episodes, respectively.

RESULTS

In multivariable analyses, declines in glucose-corrected sodium concentrations were associated with higher sodium and chloride concentrations at presentation and with previously diagnosed diabetes. Treatment with 0.45% (vs 0.9%) sodium chloride fluids was also associated with declines in sodium concentration; however, higher rates of fluid infusion were associated with declines in sodium concentration only at 12 hours. Frequencies of abnormal Glasgow Coma Scale scores and clinical diagnoses of cerebral injury were similar in patients with and without declines in glucose-corrected sodium concentrations.

CONCLUSIONS

Changes in glucose-corrected sodium concentrations during DKA treatment are influenced by the balance of free-water loss versus sodium loss at presentation and the sodium content of intravenous fluids. Declines in glucose-corrected sodium concentrations are not associated with mental status changes during treatment.

High Incidence of Hyponatremia in Patients Operated for Nonsellar/Suprasellar Supratentorial Tumors—A Prospective Observational Study

Background The incidence of hyponatremia is high in supratentorial tumors. However, most studies of supratentorial tumors have included patients with sellar/suprasellar tumors. It is common knowledge that sellar tumors have higher incidence and severity of hyponatremia. Incidence of hyponatremia is not known if we exclude sellar/suprasellar tumors. Therefore, this study was designed to evaluate the incidence of hyponatremia in supratentorial tumors after excluding sellar/suprasellar tumors.

Methods After institutional ethics committee approval and written informed consent, adult patients with supratentorial tumors (nonsellar/suprasellar) were recruited, and data were collected prospectively. In all patients, serum electrolytes were measured every 2 to 3 days. Hyponatremia was defined as serum sodium of <135 mEq/L. All the patients were followed up till death or discharge from the hospital.

Results A total of 61 patients’ data were analyzed. There were 31 male and 30 female patients with an average age of 44 years. There were 23 meningiomas, 36 gliomas, and 2 other tumors. Forty patients (66%) developed hyponatremia during hospital stay. There were 29 mild cases (serum sodium 131–134 mEq/L), 7 were moderate (serum sodium 126–130 mEq/L), and 4 were severe (serum sodium <126 mEq/L). Three hyponatremic meningioma patients died, of which two had mild hyponatremia and one had severe hyponatremia. Duration of hospital stay was longer in hyponatremic patients.

Conclusion The incidence of hyponatremia is high in supratentorial tumor patients after excluding sellar/suprasellar lesions. In the majority of patients, the disturbance is mild. Hyponatremic patients has a longer hospital stay and higher mortality.

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.

Guillain-Barré syndrome in Eastern China: A study of 595 patients

BACKGROUND AND PURPOSE

This study aimed to investigate geographical differences in the clinical features of Guillain-Barré syndrome (GBS) between patients from our region in Eastern China and patients from other areas.

METHODS

A total of 595 patients fulfilling the diagnostic criteria ​for GBS or its variants were included from two large hospitals located in Eastern China. Data collection included demographics, antecedent events, clinical presentation and signs, electrophysiological subtypes, treatment, complications during hospitalization, clinical severity at nadir, and outcome at 12 months, and these data were compared to data from a study conducted in Southern China and the Europe/Americas section of the International GBS Outcome Study.

RESULTS

The median (interquartile range) age of patients was 50 (36-61) years, the ratio of men to women was 1.2, and 49% of patients had antecedent events. Patients in our region of Eastern China had pure motor predominant GBS (158/340, 46%) and 30% (103/340) had complications during hospitalization. Patients aged over 60 years had a lower frequency of antecedent infections and single, axonal subtypes, but higher disability scores at entry, nadir, and 12 months. When compared with the Europe/Americas data, our patients had a lower frequency of antecedent infection (46% vs. 63%), cranial nerve involvement (43% vs. 49%), sensory deficits (45% vs. 69%), pain (19% vs. 57%) and mechanical ventilation (11% vs. 17%), but a higher frequency of axonal subtype (35% vs. 6%). There was a higher frequency of patients with antecedent gastroenteritis (16% vs. 8%), mechanical ventilation (11% vs. 8%) and axonal subtypes (35% vs. 19%) in our region in Eastern China than in Southern China.

CONCLUSIONS

Patients with GBS in Eastern China showed significant clinical heterogeneity and differences when compared to other geographic areas.

Occurrence of Chordoid Glioma With Sodium Ion Metabolism Disorder 5 Years After Meningioma Surgery and Whole-Exome Sequencing: A Case Report and Literature Review

Chordoid glioma (CG), a rare slow-growing brain tumor, mainly occurs in the region of the third ventricle. Although its degree of malignancy is relatively low, its clinical prognosis is poor due to obscure clinical manifestations and the particular growing position. Currently, gross total resection is the best available method for treatment of CG. However, the tumor is located in the deep structure of the brain and close to neurovascular structure so it is difficult to remove completely. This study reported a case of CG of the third ventricle 5 years after surgery of right frontal parietal fibrous meningioma, accompanied with peri and post-operative sodium ion metabolism disorder. Whole-exome sequencing (WES) revealed 25 gene mutations shared by meningioma and CG. In addition, the PRKCA ^D463H CG marker gene mutation also existed in this patient. We reviewed the latest literature on this rare brain tumor, summarized its clinical manifestations, imaging and pathological characteristics, and discussed the mechanism related to its occurrence and the reasons for sodium ion disorder.

Higher plasma NT-proBNP levels correlate with syndrome of inappropriate antidiuretic hormone and poor prognosis in neurological patients

Background

Hyponatremia induced by syndrome of inappropriate antidiuretic hormone secretion (SIADH) was common electrolyte disturbance encountered in critically ill neurological diseases, which has normal or increased fluid volume. Brain natriuretic peptide (BNP), which is released in equal proportion to N-terminal pro-brain natriuretic peptide (NT-proBNP), plays vital roles in regulation of volume status. The relationship between SIADH and NT-proBNP levels in neurological diseases has rarely been reported.

Methods

A retrospective cross-sectional study was conducted to analyze plasma NT-proBNP levels in 33 patients with SIADH and 23 controlled eunatremic patients with neurological diseases.

Results

Baseline NT-proBNP levels were compared between two groups [SIADH group: median 311 pg/mL, interquartile range (IQR) 110–768 pg/mL] vs. eunatremic group: median 46 pg/mL, IQR, 12–96 pg/mL) (P<0.05). Plasma NT-proBNP levels were markedly increased in hyponatremic patients who had two or more complications than those who had less complication (P<0.05). In SIADH patients, NT-proBNP levels in remission phase were lower to levels at baseline. Furthermore, no death was seen in eunatremic patients, while five SIADH patients died from complications.

Conclusions

SIADH had higher plasma NT-proBNP levels and poorer prognosis compared to eunatremic neurological patients. NT-proBNP serves as a biomarker of disease severity while not extracellular volume (ECV) status in critically ill neurological patients.

Minor Head Injury Might Cause Treatable Dementia Due to Severe Hyponatremia

OBJECTIVE: There are several conditions of treatable dementia. Among these, hyponatremia can cause transitory modification of cognitive functions. DESIGN: We treated a patient with cognitive decline after minor head injury who developed severe hyponatremia due to central salt wasting syndrome (CSWS). RESULTs: Head injuries can interfere with the normal neuroendocrine function of the hypothalamus and pituitary system, resulting in CSWS. A short-term infusion of isotonic saline solution might be useful in identifying CSWS. CONCLUSION: Follow-up laboratory tests, including ones that test serum sodium leves, are recommended even in patients with minor head injury to diagnose potentially reversible conditions similar to dementia.

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.

New drugs on the horizon for cerebral edema: what's in the clinical development pipeline?

INTRODUCTION

Research has advanced our understanding of the molecular and cellular mechanisms of cerebral edema and has propelled the development of novel antiedema therapeutics. Current evidence supports aberrant neuro-glial ion transport as a central mechanism that underlies pathological fluid accumulation after central nervous system injury.

AREAS COVERED

Novel agents in clinical development show potential in altering the natural history and treatment of cerebral edema. Using the PubMed and Google Scholar databases, we review recent advances in our understanding of cerebral edema and describe agents under active investigation, their mechanism, and their application in recent and ongoing clinical trials.

EXPERT OPINION

Pharmacotherapies that target molecular mechanisms underlying the compensatory post-injury response of ion channels and transporters that lead to pathological alteration of osmotic gradients are the most promising therapeutic strategies. Repurposing of drugs such as glyburide that inhibit the aberrant upregulation of ion channels such as SUR1-TRPM4, and novel agents, such as ZT-1a, which reestablish physiological regulation of ion channels such as NKCC1/KCC, could be useful adjuvants to prevent and even reverse fluid accumulation in the brain parenchyma.