Urea como opción terapéutica en síndrome de antidiuresis inadecuada

El síndrome de antiduresis inadecuada (SADI) se produce por una alteración en el eje hipotálamo-neurohipófisis, por una falla en la respuesta regulatoria osmótica o por factores no osmóticos, con complicaciones en relación directa al grado de hiponatremia e impacto en la calidad de vida y mortalidad del paciente. El tratamiento consiste en la normalización de la natremia, y la búsqueda de la etiología. Presentamos el caso de un paciente adulto con el diagnóstico de SADI idiopático y trastorno neurocognitivo asociado, con respuesta favorable al tratamiento con urea.

Syndrome of Inappropriate Antidiuresis (SIAD), is produced by an alteration in the hypothalamus-neurohypophysis axis due to a failure in the osmotic regulatory response or non-osmotic factors, with complications directly related to the degree of hyponatremia and impact on quality of life and patient mortality. Management consists of normalization of natremia, and the search for the underlying etiology. We present the case of an adult patient diagnosed with idiopathic SIAD and associated neurocognitive disorder, with a favorable response to treatment with urea.

Hiponatremia severa por meningitis tuberculosa: complicación frecuente pero olvidada

Se presenta el caso de un paciente varón de 55 años que ingresó por alteración del estado de conciencia por una hiponatremia severa secundaria a una meningitis tuberculosa. No hubo mejoría de la hiponatremia al tratamiento con solución salina hipertónica, por lo cual se planteó el diagnóstico de síndrome de secreción inapropiada de hormona antidiurética (SIADH) y se evidenció mejoría con la restricción hídrica. El interés del presente caso es reportar una complicación frecuente pero olvidada de la meningitis tuberculosa.

We present the case of a 55-year-old male patient who was admitted due to an altered state of consciousness due to severe hyponatremia secondary to tuberculous meningitis. There was no improvement in hyponatremia after treatment with hypertonic saline solution, therefore the diagnosis of syndrome of inappropriate secretion of antidiuretic hormone (SIADH) was proposed, and improvement was evidenced with fluid restriction. The interest of this case is to report a common but forgotten complication of tuberculous meningitis.

Encefalitis límbica asociada a secreción inadecuada de hormona antidiurética. Reporte de un caso y revisión de la literatura / Limbic encephalitis associated with inappropriate secretion of antidiuretic hormone. A case report and literature review / Encefalite límbica associada à secreção inapropriada de hormônio antidiurético. Relato de caso e revisão da literatura

La encefalitis límbica (EL) autoinmune es una afección neurológica infrecuente de curso subagudo con manifestaciones neuropsicológicas. Actualmente el tratamiento inmunoterápico agudo o de mantenimiento es dirigido según el anticuerpo neural acompañante y la presencia o ausencia de cáncer. Presentamos el caso de una mujer de 52 años con hipotiroidismo autoinmune, síndrome de secreción inadecuada de hormona antidiurética (SIADH) e hiponatremia (hipoNa) persistente, con evolución progresiva de perdida de la memoria y crisis distónicas faciobraquiales (DFBC) a quien se le realiza un diagnóstico oportuno de encefalitis límbica. Recibió tratamiento intravenoso combinado en base a corticoides e inmunoglobulina con buena respuesta y morbilidad mínima neuropsicológica. El reconocimiento de esta patología permite un diagnóstico y tratamiento temprano, imprescindible para mejorar el pronóstico de estos pacientes.

Autoimmune limbic encephalitis is a rather unusual neurological condition with subacute progression and neuropsychological symptoms. Currently, acute or maintenance treatment with immunotherapy is targeted depending on the accompanying neural specific antibody and the presence or absence of cancer. The study presents the case of a 52-year-old woman suffering from autoimmune hypothyroidism, syndrome of inappropriate secretion of anti-diuretic hormone (SIADH) and persistent hyponatremia, with progressive evolution which involved memory loss and faciobrachial dystonic seizures (FBDS). She was timely diagnosed with limbic encephalitis and was treated with intravenous combined corticosteroids and immunoglobulin therapy. Response was good, with minimum neuropsychological. Recognizing this condition allows for early diagnosis and treatment, what is key to improve the prognosis of these patients.

A encefalite límbica (LE) autoimune é uma condição neurológica rara de curso subagudo com manifestações neuropsiquiátrica. Atualmente, o tratamento com imunoterapia aguda ou de manutenção é orientado de acordo com o anticorpo neural e a presença ou ausência de câncer. Apresentamos o caso de uma mulher de 52 anos com hipotireoidismo autoimune, síndrome de secreção inapropriada de hormônio antidiurético e hiponatremia persistente, com evolução progressiva da perda de memória e crises distônicas faciobraquiais que foi diagnosticada oportunamente como encefalite límbica. Recebeu tratamento endovenoso combinado à base de corticoide e imunoglobulina com boa resposta e morbidade neuropsiquiátrica mínima. O reconhecimento desta patologia permite um diagnóstico e tratamento precoces, essenciais para melhorar o prognóstico desses pacientes.

A Rare Case of Hyponatremia Caused by Reset Osmostat in a Neonate with Cleft Lip, Cleft Palate, and Imperforate Anus

Hyponatremia is defined as a plasma sodium concentration of < 135 mEq/L. It is a common electrolyte imbalance in newborns. We report the case of a term neonate with cleft lip, cleft palate, imperforate anus, normal male karyotype, and chronic hyponatremia. On the 4th day of life, he showed hyponatremia (plasma sodium concentration 130 mEq/L) with low serum osmolality (275 mOsm/kg), high urine sodium (116.7 mEq/L), and high urine osmolality (412 mOsm/kg). His thyroid and adrenal functions were normal. Despite intravenous and oral sodium supplementation and hydrocortisone treatment, hyponatremia persisted. Brain magnetic resonance imaging showed normal results. He was diagnosed as having reset osmostat, a rare subtype of the syndrome of inappropriate secretion of antidiuretic hormone characterized by a subnormal threshold for antidiuretic hormone secretion, with hypotonic hyponatremia.

Disseminated herpes zoster involving bladder and severe inappropriate antidiuretic hormone in a immunocompetent elderly patient: A case report

Disseminated herpes zoster commonly occurs in patients with decreased immunity, but rarely in patients without any evidence of immunosuppression. We reported a case of disseminated herpes zoster with visceral organ involvement in a non-immunocompromised patient. An 83-year-old man visited our pain center, with chief complaints of painful rashes on the L3–L4 and S2–S4 due to acute herpes zoster. Even though intravenous antiviral therapy was initiated immediately upon hospitalization, his lesion deteriorated and systemic cluster formed. Urinary retention and hyponatremia occurred, and he was diagnosed with zoster cystitis and severe inappropriate antidiuretic hormone syndrome. Conservative treatment, including Foley catheter insertion and correction of hyponatremia with antiviral therapy, was initiated, and he was discharged without any complications at the 33rd day of hospitalization. Old age can be a risk factor of disseminated herpes zoster, and visceral organ involvement should also be considered.

Comparison of tolvaptan treatment between patients with the SIADH and congestive heart failure: a single-center experience

BACKGROUND/AIMS: Tolvaptan is a very effective treatment for hypervolemic or euvolemic hyponatremia. We compared the clinical efficacy of and response to tolvaptan in patients with the syndrome of inappropriate antidiuretic hormone secretion (SIADH) and congestive heart failure (CHF). METHODS: We retrospectively reviewed the medical records of 50 patients (SIADH, n = 30; CHF, n = 20) who were prescribed tolvaptan between July 2013 and October 2015. Tolvaptan was prescribed when the serum sodium level was 135 mmol/L. RESULTS: After the initiation of tolvaptan therapy, there was an immediate response in the urine volume and serum sodium level in all patients. The improvements in the urine volume and serum sodium concentration were highest within the first 24 hours of treatment. In addition, the mean change in the serum sodium level during the first 24 hours was significantly higher in patients with SIADH than in those with CHF (∆Na, 9.9 ± 4.5 mmol/L vs. 6.9 ± 4.4 mmol/L, respectively; p = 0.025). Also, the mean maintenance dose was lower, and the total duration of tolvaptan use was slightly shorter in the SIADH group than CHF group (21.5 ± 14.9 days vs. 28.0 ± 20.1 days, p = 0.070). CONCLUSIONS: The early response to tolvaptan treatment was better in patients with SIADH than in those with CHF. Thus, the tolvaptan treatment strategy should be differed between patients with SIADH and those with CHF.

Safety and Efficacy of Tolvaptan in Korean Patients with Hyponatremia Caused by the Syndrome of Inappropriate Antidiuretic Hormone

BACKGROUND: The aim of this multicenter study was to evaluate the safety and efficacy of tolvaptan (TLV) in Korean patients with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). METHODS: Of 51 enrolled patients with SIADH, 39 patients (16 female patients, aged 70.8 ± 11.3 years) were included in an intention to treat analysis. All patients received 15 mg/day as the initial dose, and the dose was then increased up to 60 mg/day (as needed) until day 4. RESULTS: Serum sodium increased significantly from baseline during the first 24 hours (126.8 ± 4.3 vs. 133.7 ± 3.8 mmol/L, P < 0.001), rose gradually between days 1 and 4 (133.7 ± 3.8 vs. 135.6 ± 3.6 mmol/L, P < 0.05), and then plateaued until day 11 (136.7 ± 4.5 mmol/L). The correlation between the change in serum sodium for the first 24 hours and initial serum sodium concentration was significant (r = −0.602, P < 0.001). In severe hyponatremia (< 125 mmol/L), the change was significantly higher (11.1 ± 4.8 mmol/L) than in moderate (6.4 ± 2.5 mmol/L, P < 0.05) or mild hyponatremia (4.3 ± 3.3 mmol/L, P < 0.01). In addition, logistic regression analysis showed that body weight (odds ratio [OR], 0.858; 95% confidence interval [CI], 0.775–0.976; P = 0.020) and body mass index (BMI) (OR, 0.692; 95% CI, 0.500–0.956; P = 0.026) were associated with rapid correction. No serious adverse events were reported, but in 13% of patients hyponatremia was overcorrected. CONCLUSION: TLV is effective in correcting hyponatremia and well-tolerated in Korean patients with SIADH. However, those with low body weight, low BMI or severe hyponatremia, could be vulnerable to overcorrection with the initial dose of 15 mg TLV.

Syndrome of inappropriate antidiuretic hormone secretion induced by the phytotherapy Harpagophytum procumbers: case report / Síndrome da secreção inapropriada do hormônio antidiurético induzida pelo fitoterápico Harpagophytum procumbers: relato de caso

Abstract Introduction: The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is the inability of antidiuretic hormone (ADH) suppression, compromising the mechanisms of water excretion and urinary concentration. It manifests as hyponatremia and its symptoms, especially neurological. There are many causes that trigger such disease, notably: central nervous system disorders, malignant neoplasm, drugs and others. Case Report: A 65 years female hypertensive patient presented clinical and laboratory manifestations of hyponatremia due to SIADH. It happened twice under use of herbal medication for osteoarthritis treatment. Discussion: The drug-related hyponatremia can be triggered by direct effect of the drug or by association with SIADH. The clinical manifestations presented could have been related to psychiatric condition and may have severe outcome if not properly diagnosed. The association of an herbal medicine to SIADH could be confirmed after a new episode of hyponatremia related to Harpagophytum procumbers reintroduction. Our literature review did not find this herbal medicine associated with SIADH, so far. Conclusion: SIADH may be caused by herbal medicine described from now on their association in the literature.

Resumo Introdução: A síndrome da secreção inapropriada do hormônio antidiurético (SIADH) consiste na incapacidade de supressão do hormônio antidiurético (ADH), comprometendo os mecanismos de excreção da água e concentração urinária. Possui como manifestações a hiponatremia e seus sintomas, sobretudo neurológicos. Há variadas causas que desencadeiam tal distúrbio, a se destacarem: distúrbios do sistema nervoso central, neoplasias malignas e drogas, dentre outros. Relato de Caso: Paciente feminina, 65 anos, hipertensa, apresentando manifestações clínicas e laboratoriais correspondentes à hiponatremia. O fato ocorreu em duas ocasiões em vigência de medicação fitoterápica para tratamento de osteoartrite. Discussão: A hiponatremia relacionada às drogas pode ser provocada pelo efeito direto do medicamento ou por desencadear SIADH. As manifestações clínicas apresentadas poderiam ter sido atribuídas a um quadro psiquiátrico, o que poderia ter desfecho grave, caso não diagnosticada corretamente. A associação de um fitoterápico à SIADH pôde ser confirmada após novo episódio de hiponatremia relacionado à reintrodução do Harpagophytum procumbers. Nossa revisão da literatura não encontrou este fitoterápico associado à SIADH, até o momento. Conclusão: SIADH pode ser ocasionada por medicamento fitoterápico doravante descrita sua associação na literatura.

Syndrome of inappropriate antidiuretic hormone secretion following irinotecan-cisplatin administration as a treatment for recurrent ovarian clear cell carcinoma

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) has various causes including central nervous system disorders, pulmonary and endocrine diseases, paraneoplastic syndromes, and use of certain drugs. SIADH induced by chemotherapy with irinotecan-cisplatin is not a common complication. Here, we review a case of SIADH after treatment with irinotecan-cisplatin. A 45-year-old woman received adjuvant chemotherapy (paclitaxel-carboplatin) for ovarian clear cell carcinoma, but the cancer recurred within 9 months of chemotherapy. Subsequently, a second line of combination chemotherapy containing irinotecan-cisplatin was initiated. However, 5 days after chemotherapy administration, her general condition began to deteriorate; her hematological tests revealed hyponatremia. Therefore, it is imperative to consider the possibility of SIADH in patients being treated with irinotecan-cisplatin–based chemotherapy. Proper monitoring of serum sodium levels and assessment of clinical symptoms should be performed in such patients for early diagnosis and prompt management.

Delayed diagnosis of pituitary stalk interruption syndrome with severe recurrent hyponatremia caused by adrenal insufficiency

Pituitary stalk interruption syndrome (PSIS) involves the occurrence of a thin or absent pituitary stalk, hypoplasia of the adenohypophysis, and ectopic neurohypophysis. Diagnosis is confirmed using magnetic resonance imaging. Patients with PSIS have a variable degree of pituitary hormone deficiency and a wide spectrum of clinical manifestations. The clinical course of the disease in our patient is similar to that of a syndrome of inappropriate antidiuretic hormone secretion. This is thought to be caused by failure in the suppression of vasopressin secretion due to hypocortisolism. To the best of our knowledge, there is no case report of a patient with PSIS presenting with hyponatremia as the first symptom in Korean children. Herein, we report a patient with PSIS presenting severe recurrent hyponatremia as the first symptom, during adolescence and explain the pathophysiology of hyponatremia with secondary adrenal insufficiency.

Severe Hyponatremia with Mental Change after Ingestion of Picosulfate Sodium/Magnesium Citrate for Bowel Preparation / 대한내과학회지

Picosulfate sodium/Magnesium citrate (PS/MC) is a common bowel cleansing agent for colonoscopy. It is equally effective and better tolerated by patients with regard to taste and volume than polyethylene glycol. However, because of its osmotically active characteristics, PS/MC can cause plasma volume depletion and electrolyte disturbances, such as hyponatremia. Here, we report a case of severe hyponatremia combined with loss of consciousness in a 59-year-old woman following ingestion of PS/MC as bowel preparation for a screening colonoscopy. Upon arrival, serum sodium level was 109 mEq/L and urine osmolality and sodium levels were 393 mOms/Kg and 99 mmol/L, respectively. She was euvolemic and showed normal kidney, thyroid, and adrenal function. Based on these findings, inappropriate anti-diuretic hormone syndrome (SIADH) was diagnosed. She was treated with 3% hypertonic saline and completely recovered without any neurologic sequelae. This case shows that SIADH can be caused by PS/MC (not accompanied by dehydration), even in patients without any underlying renal, heart, or liver diseases.

Stress-induced Cardiomyopathy Associated with Non-Small Cell Lung Cancer Presenting as Hyponatremia / 이화의대지

Stress-induced cardiomyopathy, so-called Takotsubo cardiomyopathy, has recently been reported in Japan. Stress-induced cardiomyopathy is characterized by transient left ventricular apical dysfunction and ballooning, with normal coronary angiographic findings. We describe a rare case of stress-induced cardiomyopathy associated with lung adenocarcinoma presenting as hyponatremia.

Syndrome of Inappropriate Secretion of Antidiuretic Hormone after Lung Transplantation / 이화의대지

A 54-year-old man was diagnosed as syndrome of inappropriate secretion of antidiuretic hormone (SIADH) 7 days after lung transplantation, whereas the preoperative serum sodium level was normal. Hypertonic saline infusion with furosemide did not improve hyponatremia, however, tolvaptan corrected his serum sodium levels from 123 mEq/L to 131 mEq/L. Seven days after maintenance of tolvaptan, this drug was discontinued and hyponatremia did not occur. Herein, we report a case of SIADH after lung transplantation treated with tolvaptan.

Preliminary observation of efficacy and safety of arginine vasopressin receptor antagonist in the treatment of syndrome of inappropriate secretion of antidiuretic hormone / 中国医师进修杂志

Objective To observe the efficacy and safety of arginine vasopressin receptor antagonist tolvaptan for treating hyponatremia caused by syndrome of inappropriate secretion of antidiuretic hormone (SIADH).Methods Six patients diagnosed with SIADH were enrolled in this study.Four cases were allocated to tolvaptan group (oral tolvaptan 15-60 mg/d,the dosage was adjusted based on the level of serum sodium).Two cases were allocated to regular treatment group (liquid was limited 1 000 ml/d,intravenous drip was less than 3％ sodium chloride and/or oral salt capsule 10-15 g/d several times was adjusted based on the level of serum sodium).Data of the level of serum sodium at 4,7 d,baseline value of serum sodium,serum sodium at the first normal time,24 h urine and weight change were collected.Safety assessment was given before and after treatment,including medical history,physical examination,electrocardiogram,laboratory tests,and incidence of adverse events.Results The level of serum sodium in tolvaptan group increased from the first day of the treatment.During the period of treatment,serum sodium at 4 d increased 22,16,14,11 mmol/L compared with the baseline value respectively.No obvious change of sodium was observed in regular treatment group compared with the baseline value.For 7 d treatment,serum sodium level increased 14,13,14,13 mmol/L in tolvaptan group compared with the baseline level respectively.Only 2 cases in regular treatment group increased 4 mmol/L,and sodium level in regular treatment group did not reach the lower limit of normal level of serum sodium.In tolvaptan group,all patients urine output increased after 1 d treatment and began to stabilize in 3 d.24 h urine putouts were much more than 1 500 ml during treatment.Urine putouts 780-1 400 ml were observed in regular treatment group.There was no difference before and after treatment.Although weight dropped after treatment in the two groups,weight in tolvaptan group fell obviously.In the two groups,there was no difference in blood pressure and heart rate before and after treatment.There were no serious complications and adverse events.Conclusions Compare with regular treatment,arginine vasopressin receptor antagonist is more effective therapy because it can correct the SIADH in patients with hyponatremia and reduce water retention.It also has a good security.

Syndrome of inappropriate anti-diuretic hormone in lung-cancer patients:six cases / 中国肿瘤临床

Objective:To investigate the clinical characteristics, treatment, and evaluation of the prognosis of syndrome of inap-propriate anti-diuretic hormone (SIADH) in lung-cancer patients. Methods:We review the clinical data of six lung cancer cases, includ-ing four small cell lung cancer, one adenocarcinoma, and one squamous cell carcinoma, with SIADH complication. All six cases were treated in our hospital over the past three years. Results:Patients with various serum sodium levels were provided different therapeutic regimens. Symptoms of fatigue and nervous system disorders, plasma sodium, urine sodium, and plasma osmotic pressure were alleviat-ed. Conclusion:SIADH is a common complication of lung cancer, particularly in small lung cancer cases. Electrolyte disturbances indi-cate poor prognosis, high mortality rate, and delay in treatment because of clinical interest. After a final diagnosis has been made and ap-propriate treatment has been administered, clinical symptoms were relieved and blood sodium levels were quickly and significantly im-proved in these patients.

Inflammation and hyponatremia: an underrecognized condition? / 소아과

Timely diagnosis of hyponatremia is important for preventing potential morbidity and mortality as it is often an indicator of underlying disease. The most common cause of eurvolemic hyponatremia is the syndrome of inappropriate antidiuretic hormone (SIADH) secretion. Recent studies have demonstrated that proinflammatory cytokines such as interleukin (IL) 1beta and IL-6 are involved in the development of hyponatremia, a condition that is associated with severe inflammation and is related to antidiuretic hormone (ADH) secretion. Serum sodium levels in hyponatremia are inversely correlated with the percentage of neutrophils, C-reactive protein, and N-terminal-pro brain type natriuretic peptide. Additionally, elevated levels of serum IL-6 and IL-1beta are found in inflammatory diseases, and their levels are higher in patients with hyponatremia. Because it is significantly correlated with the degree of inflammation in children, hyponatremia could be used as a diagnostic marker of pediatric inflammatory diseases. Based on available evidence, we hypothesize that hyponatremia may be associated with inflammatory diseases in general. Understanding the mechanisms responsible for augmented ADH secretion during inflammation, monitoring patient sodium levels, and selecting the appropriate intravenous fluid treatment are important components that may lower the morbidity and mortality of patients in a critical condition.

Hiponatremia: conceitos básicos e abordagem prática / Hyponatremia: basic concepts and practical approach

Hyponatremia is the most common electrolyte imbalance in hospitalized patients. It is associated with several unfavorable endpoints such as: the need for intensive care, longer hospital stay, higher hospitalization costs, discharge to long-term care facilities, and mortality. It is still not clear if there is a direct causal relationship or if hyponatremia is simply a marker of disease severity. Nevertheless, it is quite clear that improper management of a hyponatremic patient may result in severe neurologic damage or death. This paper addresses the basic pathophysiologic concepts about hyponatremia followed by a practical approach to its diagnosis and management.

Hiponatremia é o distúrbio hidroeletrolítico mais comum em pacientes hospitalizados. A presença de hiponatremia está associada a uma série de desfechos desfavoráveis, tais como: necessidade de internamento em unidade de terapia intensiva, hospitalização prolongada e de maior custo, transferência para abrigos e mortalidade. Ainda não está claro se existe relação de causalidade direta ou se a hiponatremia é apenas um marcador de gravidade da doença de base. No entanto, sabe-se que o manejo inadequado de um paciente hiponatrêmico pode causar graves danos neurológicos ou até mesmo a morte. Neste manuscrito, os conceitos básicos sobre a fisiopatologia da hiponatremia serão revisados, seguido de uma abordagem prática sobre sua investigação e tratamento.

Síndrome inapropriada do hormônio antidiurético (SIADH) pós-abdominoplastia / Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) post abdominoplasty

Este é um caso de síndrome inapropriada do hormônio antidiurético (SIADH) em umamulher, 39 anos, hígida, sem comorbidades importantes, submetida a abdominoplastia semlipoaspiração associada, que desenvolveu, 30 horas após a cirurgia, hiponatremia aguda(sódio 114,9 mEq/L-1), com importantes manifestações neurológicas. O difícil diagnósticoprecoce desta situação clínica grave, em pacientes saudáveis, pode causar importantes sequelasneurológicas e até mesmo o óbito. O diagnóstico precoce e a instituição de tratamentode reposição corretos são a chave para evitar lesões cerebrais irreversíveis.

This is a case of syndrome of inappropriate anti-diuretic hormone (SIADH) in a healthy woman,39 years old without comorbites, with developed postoperative acute hyponatremia (sodium 114mEq/L-1) after abdominoplasty without liposuction with important neurologic manifestations.The initial diagnosis of this syndrome in normal patients could avoid permanent neurologicdamage. The early recognition and correct treatment are vital to avoid a poor cerebral outcome.

Hyponatremia in Patients with Neurologic Disorders

The kidney and the brain play a major role in maintaining normal homeostasis of the extracellular fluid by neuroendocrine regulation of sodium and water balance. Therefore, disturbances of sodium balance are common in patients with central nervous system (CNS) disorders and clinicians should focus not only on the CNS lesion, but also on the potentially deleterious complications. Hyponatremia is the most common and important electrolyte disorder affecting patients with critical neurologic diseases. In these patients, the maladaptation to hyponatremia by impaired osmoregulation in pathologic lesions of brain may cause more aggressive cerebral edema and increased intracranial pressure due to hypoosmolality induced by hyponatremia. Furthermore, hyponatremia accompanied by CNS disorders has shown to increase delayed cerebral ischemia and mortality rates. Two main pathophysiologies of hyponatremia, excluding iatrogenic causes, are inappropriate secretion of antidiuretic hormone (SIADH) and cerebral salt wasting (CSW) syndrome. Differential diagnosis between these two entities can be difficult due to considerable overlap in the laboratory findings and clinical situations. SIADH is in a volume expanded status due to inappropriately secreted arginine vasopressin (AVP) and requires water restriction. However, CSW syndrome is characterized by renal sodium wasting mainly due to increased natriuretic peptides resulting in volume depletion and follows appropriate secretion of AVP. Therefore, maintenance of volume status and sodium replacement is the mainstay of treatment in CSW syndrome. In this review, we aimed to describe the regulation of sodium and water balance, and pathophysiology, diagnosis and treatment of hyponatremia in neurologic patients, especially focusing on SIADH and CSW syndrome.

A Case of Syndrome of Inappropriate Secretion of Antidiuretic Hormone Following Chemotherapy in a Patient with Non-Small-Cell Lung Cancer / 결핵및호흡기질환

The syndrome of inappropriate secretion of the antidiuretic hormone (SIADH) is a well recognized paraneoplastic phenomenon related to impaired water excretion, and can result in dilutional hyponatremia as well as central nervous system symptoms. It is characterized by a decrease in plasma osmolarity with inappropriately concentrated urine. The causes of SIADH are associated with pulmonary and endocrine disorders, central nervous system diseases, and malignancies, including lung cancer. The other causes of SIADH include some drugs, particularly chemotherapy agents. Anticancer drugs, such as cisplatin, vincristine, and cyclophosphamide are well known causes of SIADH but the mechanisms are unclear. Recently, we encountered a patient with advanced non-small cell lung cancer who suffered from general weakness and altered mentality after an intravenous carboplatin and gemcitabine combination.