Syndrome of hypernatremia, hypodipsia and partial diabetes insipidus: a new interpretation

When Thirst Ceases to Exist: A Case Report and Literature Review of Adipsic Diabetes Insipidus Following Coil Embolization of a Ruptured Anterior Communicating Artery Aneurysm

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.

How do phosphodiesterase-5 inhibitors affect cancer? A focus on glioblastoma multiforme

Since the discovery of phosphodiesterase-5 (PDE5) enzyme overexpression in the central nervous system (CNS) malignancies, investigations have explored the potential capacity of current PDE5 inhibitor drugs for repositioning in the treatment of brain tumors, notably glioblastoma multiforme (GBM). It has now been recognized that these drugs increase brain tumors permeability and enhance standard chemotherapeutics effectiveness. More importantly, studies have highlighted the promising antitumor functions of PDE5 inhibitors, e.g., triggering apoptosis, suppressing tumor cell growth and invasion, and reversing tumor microenvironment (TME) immunosuppression in the brain. However, contradictory reports have suggested a pro-oncogenic role for neuronal cyclic guanosine monophosphate (cGMP), indicating the beneficial function of PDE5 in the brain of GBM patients. Unfortunately, due to the inconsistent preclinical findings, only a few clinical trials are evaluating the therapeutic value of PDE5 inhibitors in GBM treatment. Accordingly, additional studies should be conducted to shed light on the precise effect of PDE5 inhibitors in GBM biology regarding the existing molecular heterogeneities among individuals. Here, we highlighted and discussed the previously investigated mechanisms underlying the impacts of PDE5 inhibitors in cancers, focusing on GBM to provide an overview of current knowledge necessary for future studies.

Endocrinological Features of Hartsfield Syndrome in an Adult Patient With a Novel Mutation of FGFR1

Hartsfield syndrome (HS: OMIM 615465) is a rare congenital disease associated with a mutation of the fibroblast growth factor receptor 1 gene (FGFR1) with the main features of holoprosencephaly and ectrodactyly. Patients with HS also present with endocrinological deficits, such as isolated hypogonadotropic hypogonadism and central diabetes insipidus. Although there are several studies on infancy/childhood history, there is no study of infant/childhood/adolescent/young adult HS natural history and endocrinological findings. Here, we report a male patient with HS associated with a novel de novo FGFR1 mutation (c. 1868A > C). The endocrinological profile was evaluated at ages 1 and 31 years. This long-term follow-up study highlights functional changes in the posterior pituitary gland and features of bone metabolism disorder. We also describe the anterior pituitary function. To our knowledge this is the first description of the natural history of an HS patient through birth to young adult age. Although the HS infants reported in the literature develop central diabetes insipidus, little is known about the serial changes in pituitary gland function during growth in HS patients. In this study we describe an adult patient with HS who showed improvement of hypernatremia during early adulthood. In addition, we emphasize the importance of prevention and treatment of osteoporosis in HS.

Pathogenesis of chronic hypernatremia with dehydrated and non-dehydrated states in hypothalamic space-occupying lesions

The present study was undertaken to determine pathophysiology of body water control in hypernatremic subjects with hypothalamic space-occupying lesions. Eight subjects with hypothalamic space-occupying lesions were divided into two groups of hypernatremia in the presence or absence of body water deficit. In 5 dehydrated hypernatremic subjects whose ages ranged from 20 to 67 years, serum sodium (Na) levels were 156.4 +/- 3.1 mmol/l; plasma osmolality (Posm), 320.6 +/- 9.8 mmol/kg; and urinary osmolality (Uosm), 246.8 +/- 46.7 mmol/kg under ad libitum water drinking. In 3 non-dehydrated hypernatremic subjects whose ages ranged from 21 to 32 years, serum Na levels were 150.3 +/- 5.4 mmol/l; Posm, 300.3 +/- 11.6 mmol/kg; and Uosm, 738.7 +/- 237.1 mmol/kg. Serum Na levels had a positive correlation with hematocrit (Ht) in 2 of 5 subjects with dehydration, but it totally disappeared in the 3 subjects without dehydration. Plasma arginine vasopressin (AVP) levels were 0.7 +/- 0.1 pmol/l, and there was no response of AVP release to intravenous administration of 5% NaCl in the subjects with dehydration. Plasma AVP was 0.7 +/- 0.1 pmol/l, and there was the reduced response of AVP release to 5% NaCl in those without dehydration. In one of 3 subjects a positive correlation between Posm and plasma AVP levels was obtained. Drinking behavior was totally abolished in the subjects with dehydration, and partly reduced in those without dehydration. The present study indicates that hypothalamic space-occupying lesions causes central diabetes insipidus and hypodipsia, and that sporadic and paradoxical release of AVP, enhanced renal concentrating ability and reduced drinking behavior may possess body water minimally in the hypernatremic subjects without water deficit.

Alterations in electrolyte equilibrium in patients with acute leukemia

BACKGROUND AND AIM

A wide array of disturbances in electrolyte equilibrium is commonly seen in patients with acute leukemia (AL). These abnormalities present a potential hazard in these patients, as that of enhancing the cardiotoxic effects of certain chemotherapeutic regimens. The literature dealing with AL-related electrolyte abnormalities and their interactions in leukemic patients was reviewed.

DATA SYNTHESIS

Sources included MEDLINE and EMBASE. The search strategy was based on the combination of 'acute leukemia', 'electrolyte abnormalities', 'acid-base disorders', 'potassium', 'sodium', 'magnesium', 'calcium', and 'phosphorus'. References of retrieved articles were also screened. A decrease in serum potassium, mainly owing to lysozyme-induced tubular damage, appears to be one of the most frequent and potentially hazardous abnormalities. Other clinically significant metabolic perturbations include hyponatremia and hypercalcemia.

CONCLUSION

A broad spectrum of electrolyte abnormalities is encountered in the clinical setting of AL, which are related to the disease process per se and/or to the therapeutic interventions. Clinicians should be vigilant for early detection and appropriate management of these disorders before the initiation of chemotherapy regimens as well as during treatment.

Myelodysplastic syndrome with central diabetes insipidus manifesting hypodipsic hypernatremia and dehydration

Central diabetes insipidus (DI) is a rare but recognized complication of myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) that is caused by leukemic infiltration to the hypothalamo-neurohypophyseal system. In rare patients in whom a wide region of the hypothalamus is involved, central DI results in hypodipsic hypernatremia and dehydration. Typical DI symptoms such as polydipsia, polyuria, and marked thirst are concealed in these cases, because the hypothalamic "thirst center" cannot send thirst stimuli to the cerebral cortex. Herein we describe a patient with MDS developing into AML, who presented with hypodipsic hypernatremia and dehydration. A diagnosis of central DI was made on the ground of a low level of serum anti-diuretic hormone (ADH) despite high serum osmolality. A magnetic resonance imaging study revealed attenuation of a physiological "bright spot" of the neurohypophysis. An induction course chemotherapy including regular-dose cytarabine and daunorubicin produced a rapid improvement of hypernatremia. The bone marrow aspirate after two courses of chemotherapy showed complete remission. At that point, ADH release and the "bright spot" were recovered. In order to correctly diagnose central DI in association with hematological malignancies, we should not overlook this atypical type of DI.

Hypernatraemia in early infancy

Hypernatraemia, defined as serum sodium > 150 mmol/l, is still seen frequently in tropical environments. We describe two infants, one with poor fluid intake and excessive wrapping and the other with a high solute intake, both of whom presented in a state of severe hypernatraemia. The pathophysiology of this condition is outlined, as are the major causes, such as sodium overload, inadequate water intake, increased water loss of non-renal origin, increased water loss of renal origin and essential hypernatraemia. The literature is reviewed and the current basis for management is appraised and discussed.

Adipsic hypernatremia in two patients with AIDS and cytomegalovirus encephalitis

In patients with acquired immune deficiency syndrome (AIDS), hypoosmolality is frequently observed, whereas hypernatremia is distinctly rare. We report two patients with advanced AIDS and cytomegalovirus (CMV) encephalitis, who developed severe hypernatremia without any thirst sensation, that is, adipsic hypernatremia. Both developed severe hypernatremia of up to 164 and 162 mmol/L, with serum osmolalities of 358 and 344 mOsmol/kg while remaining alert and denying thirst. Serum antidiuretic hormone (ADH) levels were 0.9 and 1.5 pg/mL, inappropriately low for the concomitant serum osmolalities. Vital signs were stable. During hypernatremia, urine osmolalities were 327 and 340 mOsmol/kg, and urine Na+ levels were 56 and 119 mmol/L, respectively. Periventricular white matter lesions were seen on cerebral nuclear magnetic resonance imaging (NMRI) in case 1, but the pituitary appeared normal in both cases. Survival after onset of hypernatremia was 6 and 4 weeks, respectively. Autopsy in case 1 showed typical findings of CMV encephalitis but normal pituitary, confirming that infection with HIV or CMV most likely caused the dysfunction of the central osmostat.

Reversible vasopressin deficiency in severe hypernatremia

Studies to assess the relationship between plasma arginine vasopressin concentration (Pavp) and plasma osmolality (Posm) were performed on an elderly patient with dementia who developed severe hypernatremia due to inadequate water intake following a debilitating hip fracture. Serum sodium concentrations were 174 and 196 mEq/L on two consecutive hospital admissions. During the second of these admissions, sequential measurements of Pavp and Posm were obtained as hypernatremia was gradually corrected. Pavp during this period was correlated with Posm (r = 0.887, P < 0.01), but was low despite the presence of hyperosmolality and volume depletion. Pavp decreased from 0.56 microU/mL to 0.18 microU/mL as Posm decreased from 396 to 338 mOsm/kg H2O. The regression line of this relationship intercepted the abscissa at 320 mOsm/kg H2O. Hypertonic sodium chloride infusion to reassess this relationship 2 days following the correction of hypernatremia increased Pavp only to 0.67 microU/mL while increasing Posm from 297 to 316 mOsm/kg H2O. Nevertheless, Pavp and Posm were significantly correlated (r = 0.937, P < 0.001). The slope of the regression line was 0.031, and Posm at the abscissal intercept was 292 mOsm/kg H2O. A similar increase in Posm from 290 to 310 mOsm/kg H2O during hypertonic sodium chloride infusion 11 days following the correction of hypernatremia increased Pavp to 1.95 microU/mL (r = 0.786, P < 0.05). The magnitude of the increase in Pavp at this time was equivalent to that previously observed in studies of normal subjects. The slope (0.048) and abscissal intercept (280 mOsm/kg H2O) of linear regression were also consistent with observations in studies of normal subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypothalamic failure as a sequela of heterozygous protein C deficiency?

Protein C deficiency can lead to cerebrovascular occlusive disease. We describe a patient in whom heterozygous protein C deficiency (type 1) is suspected on the grounds of reduced protein C activity and who suffered from multiple thrombo-embolic events involving the brain and peripheral organs. The patient developed hypothalamic failure with hypernatraemia, hypodipsia, hypersomnolence and hyperkapnia, obesity, hyperprolactinaemia, hypogonadotropic hypogonadism and growth hormone deficiency. We hypothesize that protein C deficiency caused cerebrovascular occlusions which eventually led to hypothalamic insufficiency in this patient. Disorders of the anticoagulant system should be looked for in patients with unexplained hypothalamic disease.

Hypodipsic hypernatremia and hypertriglyceridemia associated with cleft lip and cleft palate: a new hypothalamic dysfunction syndrome?

We report on a 4-month-old girl with congenital hypodipsic hypernatremia resulting from decreased sensitivity of the hypothalamic osmoreceptors with increased tonicity in association with hyperlipemia and cleft lip and cleft palate. We postulate that the link among these various derangements is hypothalamic dysfunction.

Hypodipsia and hypernatremia in congenital hydrocephalus

The authors describe a case of hypodipsia and severe hypernatremia most probably secondary to hydrocephalus in a 22-year-old man in the absence of abnormalities of ADH secretion or metabolism. The patient became hypernatremic only in situations when the decreased spontaneous fluid intake was insufficient to replace that lost caused by sweating or vomiting. Adequate hydration returned the sodium value to normal.

Hypernatraemia due to a reset osmostat for vasopressin release and thirst, complicated by nephrogenic diabetes insipidus

We describe a patient with chronic hypernatraemia (plasma sodium 148-155 mmol/l) and partial nephrogenic diabetes insipidus who had received prolonged lithium treatment. Despite stopping the drug for one year the abnormalities remained. Infusion of hypertonic saline (NaCl 855 mmol/l) allowed the characterization of osmoregulation of thirst and vasopressin secretion. Linear regression analysis of plasma vasopressin and osmolality defined the function, pAVP = 0.27 (pOsm - 301), and analysis of thirst measured by a visual analogue scale and plasma osmolality, the function, thirst = 0.16 (pOsm - 302) where pAVP and pOsm represent plasma arginine vasopressin and osmolality respectively. The slopes of the regression lines which describe the sensitivity of the osmoreceptors were within the normal range, but both abscissal intercepts, which define the thresholds for vasopressin release and thirst, were markedly elevated in comparison to normal (upper limit less than 290 mOsm/kg). Other investigations of electrolytes, anterior pituitary function and high definition computed tomographic scanning of hypothalamo-pituitary region were all normal. We conclude that this patient's chronic hypernatraemia was due to resetting of the osmostats for both vasopressin release and thirst, a rarely described mechanism to account for hypernatraemia. Although it is probable that the partial nephrogenic diabetes insipidus was related to prolonged lithium therapy, the cause of the reset osmostats remains unclear.

Hypodipsic hypernatremia associated with absence of septum lucidum and olfactory dysfunction

A case of hypodipsic hypernatremia in a 16-month-old Japanese boy is reported. Partial antidiuretic hormone deficiency was present. Computed tomography of the brain revealed absence of septum lucidum. No ophthalmological abnormality could be found. He had hyposmia, which has not been reported previously in association with hypernatremia due to hypodipsia. Forced fluid administration and nasal 1-deamino-8-d-arginine vasopressin treatment could maintain serum electrolyte levels within normal ranges. However, episodes of hypernatremia could not be completely avoided while he was treated with 1-deamino-8-d-arginine vasopressin and ad libitum oral fluid.

Selective osmoreceptor dysfunction presenting as intermittent hypernatremia following surgery for a pituitary chromophobe adenoma

Intermittent hypernatremia following hypothalamic surgery or trauma is usually attributed to the triphasic dysfunction of vasopressin release (diabetes insipidus, inappropriate vasopressin release, and diabetes insipidus). A 39-year-old patient had hypodipsia and intermittent hypernatremia following hypothalamic surgery for a chromophobe adenoma. Mean arterial pressure fell by 25 percent during orthostasis testing and was associated with an increase in vasopressin levels from 1.3 microU/ml to 12 microU/ml. Plasma renin activity and aldosterone increased from 1.1 to 16 ng/ml per hour and from 6.7 to 39 ng/dl, respectively, and remained elevated for three and a half hours after tilt testing. Hypertonic saline infusion, on the other hand, increased serum osmolality from 290 to 304 mOsm/kg but did not result in a significant rise in vasopressin levels (all were less than 1 microU/ml). These results are consistent with a selective dysfunction of the osmoreceptor pathways of vasopressin release and intact volume receptor-mediated pathways. Patients with intermittent hypernatremia following hypothalamic surgery or trauma should be questioned specifically regarding thirst. If it is impaired or absent, these patients should be watched carefully, not only for the development of triphasic dysfunction of vasopressin release, but also for a selective osmoreceptor dysfunction associated with thirst deficits as found in patients with "essential hypernatremia."

Cerebral effects of isovolemic hemodilution with a hypertonic saline solution

In view of a growing interest in the resuscitative use of hypertonic saline solutions, the authors have examined the cerebral effects of isovolemic hemodilution carried out over 1 hour (hematocrit decreased from 40% to 20%, stable arterial and right arterial pressures), using a hypertonic lactated Ringer's solution (HT-LR: Na+ 252 mEq/liter, osmolality 480 mOsm/liter). Experiments were carried out in anesthetized ventilated rabbits. Measured variables included cerebral blood flow (using the H2 clearance method), intracranial pressure (ICP), the electroencephalogram, spinal cord and skeletal muscle water content (%H2O), and the specific gravity of small (10- to 30-mg) tissue samples taken from different areas of the left hemisphere (including the cortex, thalamus, internal capsule, and hippocampus). The changes produced by HT-LR were compared with those seen in both undiluted control animals and in rabbits hemodiluted with normal saline (Na+ 155 mEq/liter, osmolality 310 mOsm/liter). The results demonstrate that hemodilution with HT-LR leads to the expected increases in serum Na+ and osmolality (158 +/- 6 mEq/liter and 320 +/- 5 mOsm/kg, respectively, mean +/- standard deviation) and that these were accompanied by reductions in the %H2O of all cerebral and extracerebral tissues, increases in the specific gravity of all tissue regions studied, and a decrease in ICP (1.9 +/- 0.7 mm Hg). By contrast, rabbits with hemodilution by normal saline showed no changes in either %H2O or specific gravity, but had significant increases in ICP (3.3 +/- 1.3 mm Hg). Cerebral blood flow increased in all animals hemodiluted with either HT-LR or normal saline by a combined average of +29 ml/100 gm/min. Although these studies were performed in neurologically normal animals, the combination of cerebral changes seen with HT-LR (cerebral dehydration, less peripheral edema, decreased ICP but with increased cerebral blood flow) suggests that this approach may have some advantages over the use of isotonic fluids, and may have some utility in the resuscitation of head-injured patients.

Chronic hypernatremia from a congenital defect in osmoregulation of thirst and vasopressin

An infant with microcephaly and delayed development was found to have chronic asymptomatic hypernatremia. Computerized brain tomography disclosed dysplasia of the midline structures, septum pellucidum and corpus collosum. Evaluation revealed defective osmoregulation, hypothalamic hypothyroidism, and hypogonadotropinism. He showed no desire to drink at plasma osmolalities over 330 mOsm/kg. His plasma vasopressin levels (less than or equal to 1.4 pg/ml) were inappropriately low relative to his high levels of plasma osmolality (greater than or equal to 310 mOsm/kg), which might be accounted for by either deficient neurohypophyseal vasopressin stores or disturbance of the hypothalamic osmoreceptors governing vasopressin. The first possibility was ruled out by demonstrating normal vasopressin response (167 pg/ml) to nonosmotic (emetic) stimulation. Under baseline conditions, his urine was concentrated up to 747 mOsm/kg and urine volume was low. With water loading, maximal water diuresis developed (urine osmolality 68 mOsm/kg), but his plasma osmolality remained in the hyperosmolar range (312 mOsm/kg). Treatment with a vasopressin analogue, desamino-D-arginine vasopressin, and forced hydration restored plasma osmolality and plasma sodium to normal. These findings indicate a severe defect in the hypothalamic osmoreceptors controlling thirst and vasopressin secretion with normal vasopressin stores and preserved vasopressin responsiveness to nonosmotic stimuli. To our knowledge, this report provides the first documentation of selective osmoreceptor defect in conjunction with congenital dysplasia of midline brain structures.

Hypodipsia in geriatric patients

Hypernatremia in elderly patients is most often due to the patients mental incapacity or physical inability to obtain water despite intact thirst sensation. Hypodipsia leading to hypernatremia is not often considered in alert, elderly subjects since hypodipsia is not a recognized consequence of nonaphasia-producing cerebrovascular accidents. Described herein are six elderly patients who had such cerebrovascular accidents and who had recurrent hospitalizations for dehydration and hypernatremia. Hypernatremia in this group was due to hypodipsia and could only be prevented by prescribing daily fluid intake as a medication order. Hypodipsia should be considered as a cause of hypernatremia in elderly subjects even when they seem fully capable of requesting and obtaining water.

Neurogenic disorders of osmoregulation

The osmolality of body fluids is normally maintained within a narrow range. This constancy is achieved largely via hypothalamic osmo-receptors that regulate thirst and arginine vasopressin, the antidiuretic hormone (ADH). Anything that interferes with the full expression of either osmoregulatory function exposes the patient to the hazards of abnormal increases or decreases in plasma osmolality. Hyposmolality is almost always due to a defect in water excretion. Increased intake may contribute to the problem but is rarely, if ever, a sufficient cause. Impaired water excretion can be due to a primary defect in the osmoregulation of ADH (inappropriate antidiuresis) or secondary to nonosmotic stimuli like hypovolemia or nausea. The two types differ in clinical presentation and treatment. Resetting of the ADH osmostat is commonly associated with resetting of the thirst osmostat. Hyperosmolarity is almost always due to deficient water intake. Excessive excretion may contribute to the problem but is never a sufficient cause. Impaired water intake can result from a defect in either the osmoregulation of thirst of the necessary motor responses. Thirst may be deficient because of primary osmoreceptor damage as in the syndrome of adipsic hypernatremia or secondary to nonosmotic influences on the set of the system. They are distinguishable by the clinical presentation as well as the type of ADH defects with which they are associated. So-called essential hypernatremia due to primary resetting of the osmostat has been postulated, but unambiguous evidence for such an entity has not yet been reported.

Diabetes insipidus: a physiologic approach to diagnosis

Diabetes insipidus can be delineated in the context of the normal physiology of water metabolism. This approach highlights the common pathway taken by the variety of diseases that can progress to an insufficiency of antidiuretic hormone (ADH) and to diabetes insipidus. A simple diagnostic approach uses homeostatic pathways to separate diabetes insipidus from the other polyuric states. New developments in the biochemical alteration of ADH have improved the ability to individualize hormonal replacement and promise better therapy in the near future.

Disordered control of thirst in hypothalamic-pituitary sarcoidosis

We evaluated water metabolism in 11 patients with hypothalamic-pituitary sarcoidosis. Seven patients had abnormal water metabolism: one had partial antidiuretic hormone (ADH) deficiency, one had severe ADH deficiency, one had severe ADH deficiency and deficient thirst, one had only deficient thirst, and three had excessive thirst. In four of the five with thirst disturbances, there was loss of congruence of osmotic thresholds for thirst and ADH release. Five of our patients presented with polyuria and polydipsia, but only two had true diabetes insipidus, whereas three had organic primary polydipsia with adequate endogenous ADH. That disordered thirst resulting in polydipsia was more common than true diabetes insipidus is at odds with previously held views on the prevalence of ADH deficiency in this condition.

Neurogenic hypernatraemia: case report

A 49-year-old man was submitted to neurosurgery for a cranio-pharyngioma. The lesion, which appeared to involve the antero-inferior wall of the third ventricle, caused lack of appropriate antidiuretic hormone (ADH) release in response to hypernatraemia and plasma hyperosmolality. The probable mechanism of this hypothalamic syndrome is suggested.

Perturbations in fluid balance induced by medially placed forebrain lesions

Acute and chronic effects on the fluid balance of radio-frequency forebrain lesions were studied in the goat. Medial lesions which involved practically the entire anterior wall of the third cerebral ventricle cause persistent loss of thirst and lack of significant antidiuretic hormone (ADH) release in response to hypernatraemia and plasma hyperosmolality. As acute response to such lesions an uncompensated, temporary water diuresis was seen, which rapidly caused pronounced hypernatraemia and hypovolaemia. Lesions extending laterally to encroach upon the supraoptic nuclei resulted in persistent signs of weak, inappropriate ADH secretion (=impaired water diuresis, renal salt wasting, and pronounced hyponatraemia during hydration). Forebrain damage, mainly restricted to the septal region, caused hyperdipsia. In some goats, obvious post-lesioning increase in salt appetite was observed which could not be coreelated to the extent of their forebrain damage. The results are discussed in relation to hypothalamic syndromes in man and previous studies on central control of fluid balance in the goat.