Investigation and management of hypotonic polyura is a common challenge in clinical endocrinology. The three main causes, recently renamed to arginine vasopressin deficiency (AVP-D, formerly central diabetes insipidus), AVP-resistance (AVP-R, formerly nephrogenic diabetes insipidus), and primary polydipsia (PP) require accurate diagnosis as management differs for each. This new nomenclature more accurately reflects pathophysiology, and has now been adopted by the Systemised Nomenclature of Medicine (SNOMED). Advances in diagnosis over the last few years have centered around the use of copeptin measurement. Here, we use three patient case histories to highlight the use of this approach, and to demonstrate how it can succeed where other approaches, such as the water deprivation test, sometimes fail. We discuss the overall approach to each type of patient and the strengths and limitations of diagnostic strategies, illustrating the use of the new nomenclature.

UNASSIGNED: Causes of epileptic seizures are often multifactorial but for an effective therapy, they should be uncovered in detail.
UNASSIGNED: We present a 67-year-old male patient with a central diabetes insipidus, who experienced a generalized tonic-clonic seizure. The patient was treated with levetiracetam for prevention of further seizures, opioids and non-steroidal anti-inflammatory drugs, i.e., ibuprofen because of severe back pain due to vertebral compression fractures. In this setting, he developed significant hyponatremia and experienced another epileptic seizure. After stopping analgesics and switching from levetiracetam to lacosamide, sodium levels returned to normal and the patient remained free of seizures since then.
UNASSIGNED: The interrelationships of medical therapy, sodium levels and epileptic seizures in the context of central diabetes insipidus are discussed.

UNASSIGNED: The first-line surgical management of an adrenocorticotropic hormone (ACTH)--secreting pituitary adenoma causing Cushing\'s disease (CD) is endoscopic transsphenoidal resection of the tumor. This study was performed to assess postoperative (postop) complications and remission in endoscopic surgically resected cases of CD.
UNASSIGNED: Data of patients who underwent endoscopic transsphenoidal surgery (ETSS) for CD were collected from the neurosurgery department at a tertiary care center in a retrospective manner from January 2015 to February 2022 and analyzed. Postoperative remission was categorized as - early morning serum cortisol <138 nmol/L within 7 days of the surgery, as per the Endocrine Society Guidelines, with significant clinical improvement in features of hypercortisolism in the operated patient and strict cutoff rate of <50 nmol/L at postop day 3 was also utilized, to look for the early identification of remission.
UNASSIGNED: A total of 41 patients were identified who underwent 44 ETSS during the same timeframe. Preoperative magnetic resonance imaging localized an adenoma in all 41 patients, out of which 32 were microadenoma, and nine were macroadenoma (2 with cavernous sinus invasion). Intrapetrosal sinus sampling was performed in 35 (85%) patients. The rate of remission for the initial surgery was 85.4% using the standard criteria and 68.3% using strict criteria. Three patients underwent early repeat surgery for the persistent disease as the day 3 cortisol was high (306-555 nmol/L). Once the outcome of this surgery was also included, the overall rate of remission was 90.2% (37/41). None of the patients had meningitis, cerebrospinal fluid leakage, visual deterioration, or vascular injury. Permanent and transient diabetes insipidus (DI) occurred in 9.75% and 26.8% following the first ETSS, respectively. We also noted a single case of CD recurrence in 9 months during the total follow-up period of 84 months.
UNASSIGNED: ETSS has satisfactory rates of remission for the primary treatment of CD, with rates being higher for microadenomas. A long follow-up period is needed to assess the rates of recurrence. Patients must be counseled regarding the risk of postop DI, whether transient or permanent, as a possible complication.

UNASSIGNED: Sheehan syndrome (SS) typically involves the loss of anterior pituitary cells and rarely affects the posterior pituitary. The water deprivation test (WDT) is the gold standard for diagnosing central diabetes insipidus (CDI), but it is cumbersome. Serum copeptin measurements are an alternative for CDI diagnosis. In this study, we measured hypoglycaemia-stimulated serum copeptin in SS patients to assess posterior pituitary function alongside anterior pituitary hormone levels.
UNASSIGNED: This study recruited 43 patients with SS on stable hormonal replacement except for growth hormone (GH), 18 patients with CDI, and 19 body mass index (BMI) and parity-matched controls. All patients with SS and four patients with CDI underwent an insulin tolerance test (ITT), and hypoglycaemia-stimulated copeptin levels were measured at 0, 30, 45, and 90 minutes after insulin injection.
UNASSIGNED: The mean serum copeptin level among patients with SS (26.01 ± 12.41 pmol/L) was significantly lower than that in healthy controls (31.92 ± 7.85 pmol/L) and higher than that in patients with CDI (1.81 ± 0.14 pmol/L). Using pre-defined cut-offs for CDI, basal serum copeptin <2.69 pmol/L and stimulated levels <4.92 pmol/L for complete central DI, and basal copeptin levels >2.69 pmol/L and stimulated copeptin <4.92 pmol/L for partial central DI, 9.2% (n = 4) of patients with SS had CDI, of which half had complete CDI and half had partial CDI.
UNASSIGNED: A significant number of patients with SS who are on hormone replacement therapy show involvement of the posterior pituitary, despite not displaying symptoms.

Az újszülött- és csecsemőkori hypernatraemia lázat okozó hatására 100 évvel ezelőtt Heim Pál is felhívta a figyelmet. Az évszázados ismeret ellenére ritkán gondolunk ennek lehetőségére. Egy négynapos, láz miatt felvett fiú újszülött esete kapcsán mutatjuk be az újszülöttkori hypernatraemia elkülönítő kórisméjét. A hypernatraemia ebben a korban az esetek döntő részében elégtelen anyatejes táplálás, 10%-ot meghaladó súlyvesztés következménye. A súlyvesztés mértéke arányos a hypernatraemia fokával. A lázért azonban nem a folyadékhiány, hanem a hypernatraemia a felelős, ahogy azt csecsemők sómérgezéssel járó esetei mutatják. Mind a dehidráció, mind a sómérgezés következtében fellépő hypernatraemia fokozott vizeletozmolalitással jár, a frakcionális nátriumkiválasztás azonban csak sómérgezésben magas. A felvett újszülött vizeletozmolalitása azonban alacsony, 100 mOsm/kg alatti, fajsúlya 1005 g/l volt. A hypernatraemia és a hipozmoláris vizelet együttes fennállása diabetes insipidusra utal. Ennek leggyakoribb, X-hez kötött, renalis formáját igazolta a genetikai vizsgálat, az AVPR2 öröklött variánsának kimutatásával. A gyermek polyuriája hipotiazid- és indometacinkezelés hatására jelentősen csökkent, a folyadékbevitel ad libitum biztosításával nem alakult ki a következő hónapokban hypernatraemia. Orv Hetil. 2024; 165(29): 1107–1111.

OBJECTIVE: Central diabetes insipidus or vasopressin deficiency (AVP-D) is the most frequent water balance disorder after transsphenoidal surgery (TSS) with variable prevalence amongst studies. We aimed to determine rates of newly developed transient or permanent AVP-D in patients with pituitary tumours treated with TSS.
METHODS: We performed systematic review of Medline, Embase, and Cochrane Library between January 1, 2000 and January 31, 2021 for studies reporting on outcomes for pituitary adenoma, craniopharyngioma, and Rathke\'s cleft cyst (RCC) after TSS and providing definition of post-operative AVP-D. We pooled the results as proportions with 95% confidence intervals (CIs) using Freeman-Tukey transformation random effects meta-analysis.
RESULTS: From 11 694 studies, 51 were included. Rates of transient or permanent AVP-D were: 17% (95% CI, 13-21) and 3% (95% CI, 2-5) in total group, 16% (95% CI, 12-21) and 2% (95% CI, 2-3) in pituitary adenomas, 31% (95% CI, 24-39) and 30% (95% CI, 22-39) in craniopharyngiomas, and 35% (95% CI, 16-57) and 14% (95% CI, 6-23) in RCCs, respectively. Based on diagnostic criteria, rates of transient or permanent AVP-D were: For hypotonic polyuria, 14% (95% CI, 8-22) and 3% (95% CI, 1-4), for hypotonic polyuria and hypernatraemia, 21% (95% CI, 13-29) and 5% (95% CI, 2-11), and for desmopressin administration, 22% (95% CI, 15-29) and 9% (95% CI, 0-30), respectively.
CONCLUSIONS: Following TSS, a small proportion of patients with pituitary adenoma have permanent AVP-D (2%), but prevalence reaches 30% in ones with craniopharyngioma and 14% in those with RCC. Diagnostic criteria for post-operative AVP-D remain variable affecting reported rates of this condition.

Diabetes insipidus is a condition characterized by inappropriately dilute urine in the setting of serum hyperosmolality. The two predominant subtypes include central (from lack of vasopressin production) and nephrogenic diabetes insipidus (from renal resistance to circulating vasopressin). A common manifestation is the significant pursuant thirst from excessive polyuria. We present a case report and literature review of an infrequent variation of central diabetes insipidus known as adipsic (hypothalamic) diabetes insipidus, characterized by the absence of thirst, secondary to coiling of a ruptured anterior communicating artery aneurysm. Due to the loss of thirst, patients are at a heightened risk for hypernatremia and complications secondary to dehydration. Our patient\'s course was complicated by recurrent polyuria and hypernatremia, requiring a fixed-dose desmopressin regimen. On follow-up, only partial thirst sensation was restored. We provide a literature review to compare our case report to the scant literature available to broaden the awareness of this infrequent, perilous, manifestation.

BACKGROUND: Langerhans cell histiocytosis (LCH) is characterized by diabetes insipidus and is an uncommon occurrence. Pathological biopsies still have a certain degree of diagnostic probability. We present a case in which LCH initially affected the pituitary gland. This resulted in a misdiagnosis of chronic inflammation upon pathological examination.
METHODS: A 25-year-old female exhibited symptoms of diabetes insipidus. Magnetic resonance imaging revealed an enhanced foci in the pituitary gland. After surgical resection of the pituitary lesion, the pathological diagnosis was chronic inflammation. However, the patient later experienced bone destruction in the skull and lower limb bones. After the lower limb bone lesion was compared with the initial pituitary lesion, the final diagnosis was modified to LCH. The patient was treated with multiple chemotherapy courses. However, the patient\'s condition gradually worsened, and she eventually passed away at home.
CONCLUSIONS: LCH should be considered when patients exhibit diabetes insipidus and absence of high signal intensity in the pituitary gland on sagittal T1-weighted image and abnormal enhancement in the pituitary region.

患者男性60岁，病程1年余。以垂体占位引起的中枢性尿崩症起病，伴主动脉周围软组织包绕、腹膜后病变、渗出性多浆膜腔积液、长骨受累，临床表现类似IgG4相关性疾病。查血IgG4浓度正常（0.928 g/L）。左胫骨上段骨病变组织活检病理检查，确诊脂质肉芽肿病（Erdheim-Chester病）。予泼尼松（50 mg每日1次）、沙利度胺（100 mg每晚1次）、去氨加压素（0.05 g每日1次）治疗，1个月后患者气促、多尿症状改善，随访半年患者胸腔积液未再增多。通过对本例的分析和总结，临床医生应提高对脂质肉芽肿病这类少见疾病的关注和认识，了解其与IgG4相关性疾病的鉴别要点，降低误诊和漏诊率。.

Vasopressin infusion is commonly used in intensive care settings during states of advanced vasodilatory shock for its vasoconstrictive properties. Vasopressin also acts on renal tubular cell receptors in the collecting ducts of kidneys to allow for water reabsorption. The sudden discontinuation of vasopressin infusion can lead to the development of transient diabetes insipidus (DI) with classic findings of polyuria, dilute urine, and hypernatremia. We report the case of a 59-year-old male who underwent an emergent bedside cricothyrotomy procedure secondary to papillary carcinoma of the thyroid and subsequently developed septic shock requiring initiation of vasopressin infusion for hemodynamic support. He remained on vasopressin for five days before the infusion was discontinued after clinical improvement. Within 12 hours of vasopressin discontinuation, the patient developed polyuria (> 3 L/day urine output) with volumes as high as 1 L per hour. His serum sodium levels increased more than 10 mmol/L from 137 to 149 mmol/L. This case is unique from prior reports, as our patient was without any neurological or neurosurgical comorbidities that would predispose him to an organic central cause of DI. Furthermore, the patient\'s large-volume diuresis and serum abnormalities spontaneously self-improved within 24 hours without significant medical intervention. In conclusion, this case adds to a growing number of reports of transient DI following vasopressin withdrawal, demonstrating the need to formally recognize this occurrence as a potential consequence of vasopressin use in intensive care settings.