1/11. Idiopathic hypothalamic dysfunction with precocious puberty and adipsic hypernatremia first presenting in adolescence.BACKGROUND: Idiopathic hypothalamic dysfunction is a rare syndrome that has been described in young children. This syndrome is characterized by a disturbance of thirst regulation with hypernatremia, hyperosmolarity, and altered hypothalamic function. PATIENT REPORT: At age 6 years the reported patients presented with precocious puberty, by age 12 years she had hypernatremia presumed secondary to central diabetes insipidus and was treated with DDAVP, and at age 14 was identified to have hyperprolactinemia. At age 19 she presented with serum sodium of 185 mg/dl during an episode of illness associated with dehydration. After hydration, her sodium remained elevated. arginine vasopressin was measurable but inappropriate to serum sodium, while urinary cyclic amp response to vasopressin was appropriate. CONCLUSIONS: This is the first case of precocious puberty identified in association with the more classic features of idiopathic hypothalamic dysfunction, including later-onset hypernatremia, poor thermoregulatory function, obesity, and hyperprolactinemia.- - - - - - - - - - ranking = 1keywords = thirst (Clic here for more details about this article) |
2/11. Hypothalamic adipic hypernatraemia syndrome with normal osmoregulation of vasopressin.Adipsic hypernatraemia is an uncommon disorder in childhood caused by a defect in the osmoregulation of thirst, leading to impairment of water homeostasis and chronic hyperosmolality of body fluids. Adipsia is often associated with an abnormality in osmoregulated vasopressin secretion due to the close proximity of the hypothalamic osmoreceptors that control thirst with those regulating vasopressin secretion. Hypothalamic lesions of diverse aetiology (vascular abnormalities, neoplasms, granulomatous diseases, trauma etc.) have been described in this syndrome. We report a 12-year-old boy with evident weight loss due to hypernatraemic dehydration with a selective defect in osmoregulation of thirst and normal vasopressin secretion with no demonstrable structural lesion. To date, only six paediatric patients with this condition have been described in the literature. Conclusion: Hypothalamic adipsic hypernatraemia syndrome must be suspected when a dehydrated patient denies thirst. The study of antidiuretic function is necessary because the osmoregulation of vasopressin secretion could be altered.- - - - - - - - - - ranking = 4keywords = thirst (Clic here for more details about this article) |
3/11. Cyclic 3',5'-adenosine monophosphate (cAMP) in a 42-month-old child with clinical evidence of multiple hormonal disturbances.In a boy aged 42 months, small stature, retarded psychomotor development, dry skin, excessive thirst, polyuria, cryptorchidism, and rickets were signs of multihormonal disturbances. Contrary to the clinical manifestations, laboratory investigations showed normal or raised levels of hormones (hGH, insulin, T3RU, T4, TSH, PTH). The cAMP level in the plasma was low and its urinary excretion was reduced. After administration of hGH, adrenaline, T3, T4, pitressin, vitamin D3 and aminophylline there was no rise in the cAMP concentration in plasma and urine. In the light of these results it may be assumed that deficient function of the adenyl cyclase system led to development of a clinical syndrome of tissue insensitivity to multiple hormonal factors in this case.- - - - - - - - - - ranking = 1keywords = thirst (Clic here for more details about this article) |
4/11. Dipsogenic diabetes insipidus: a newly recognized syndrome caused by a selective defect in the osmoregulation of thirst.We describe three patients who have polydipsia and polyuria due to an abnormality in the osmoregulation of thirst. The clinical manifestations of the syndrome are similar to those of neurogenic diabetes insipidus. Thus, under basal conditions the patients have thirst, normal to high normal levels of plasma osmolality, and low levels of plasma vasopressin. Moreover, antidiuretic therapy greatly reduces thirst and polydipsia as well as polyuria. The only clinically distinguishing feature of the response is that thirst and water intake decrease less rapidly than water excretion. As a consequence, the patients with this syndrome develop variable degrees of dilutional hyponatremia and hypoosmolemia during treatment. The plasma vasopressin response to osmotic stimulation is relatively normal. In most of the patients, the osmotic threshold for vasopressin release is at the upper limit of normal, but this finding only explains their modest elevation in basal plasma osmolality. thirst and water intake also change as a function of plasma osmolality. However, the threshold or "set" of the thirst osmostat appears to be abnormally low. The degree of downward resetting varies from patient to patient, but is always sufficient to stimulate thirst and water intake at levels of plasma osmolality below the normal range. This abnormality can account not only for the thirst and polyuria under basal conditions but also for the overhydration that occurs during antidiuretic therapy. The pathogenesis of the osmoregulatory abnormality is unknown but may be due to disruption of one or more of the afferent pathways that regulate the "set" of the thirst and vasopressin osmostats.- - - - - - - - - - ranking = 12keywords = thirst (Clic here for more details about this article) |
5/11. Arginine-vasopressin in essential hypernatremia.Dynamics of AVP secretion in a 14-year-old girl with essential hypernatremia, psychomotor retardation and optic nerve coloboma, are reported. Basal levels of AVP were similar to those of a control population, but disproportionately low in relation with natremies. Hypertonic saline and hydric restriction did not alter the AVP basal values, which were, instead, stimulated with orthostatism. AVP decreased during a water surcharge, but delayed elimination of water was observed. The existence of a moderate volume deficit, not corrigible with a chronic surcharge of water, together with the reversed diurnal pattern of water excretion and the AVP data, suggest--as a physiopathological basis of the syndrome--a severe anomaly of the osmoreceptors, with alteration of thirst and of the osmodependent AVP responses, so that the AVP secretion was regulated exclusively through volumetric mechanisms.- - - - - - - - - - ranking = 1keywords = thirst (Clic here for more details about this article) |
6/11. Hyponatraemic-hypertensive syndrome due to unilateral renal ischaemia in women who smoke heavily.The hyponatraemic-hypertensive syndrome due to renal ischaemia is presumed to be uncommon. We describe four patients who presented with this syndrome over a period of 21 months. All were women who smoked heavily and had unilateral atherosclerotic renal ischaemia. Hypokalaemia was present in each patient, and in one case resulted in recurrent ventricular tachycardia. All had noted thirst, polyuria, and weight loss. Initiation of treatment with a converting-enzyme inhibitor reduced arterial pressure precipitously in two patients. Removal of the ischaemic kidney, or chronic therapy with a converting-enzyme inhibitor reversed the biochemical abnormalities and the presenting symptoms, and lowered arterial pressure. Detailed studies in two patients before and after treatment confirmed the central role of the renin-angiotensin system in the development of the hyponatraemic-hypertensive syndrome.- - - - - - - - - - ranking = 1keywords = thirst (Clic here for more details about this article) |
7/11. Hypodipsia-hypernatremia syndrome.The pathogenesis of the rare hypernatremia, usually described in the literature as "neurogenic" or "essential" hypernatremia, consists of defective thirst mechanism either alone or in combination with impaired osmoregulation of ADH release. As etiology, disturbances of the neoplastic, vascular and degenerative type and malformations in the hypothalamic area are known. In patients with the hypodipsia-hypernatremia syndrome, dysfunction of the anterior pituitary lobe, obesity, abnormal regulation of body temperature, psychomotor retardation and episodic muscular weakness are frequently encountered as additional abnormalities. A 6-year-old patient is described with hypodipsia-hypernatremia syndrome manifest for 3 years. Besides hypernatremia, hypodipsia and the relative insensitivity of the osmoreceptors regulating ADH release, elevated body temperature, polyphagia and obesity, partial hypothalamic-hypophyseal dysfunction, lethargy and psychomotor retardation are the principal findings. An inflammatory lesion or one occupying an intracranial space was not demonstrable until now. Under forced water intake and hypocaloric diet the patient has progressed well with nearly complete normalization of the hypernatremia, body temperature and obesity.- - - - - - - - - - ranking = 1keywords = thirst (Clic here for more details about this article) |
8/11. Effect of naloxone in a previously undescribed hypothalamic syndrome. A disorder of the endogenous opioid peptide system?A syndrome of disordered hypothalamic function with abnormal control of temperature, appetite, and thirst, hyperprolactinaemia, and inappropriate vasopressin release is described in a 13-year-old boy who, in addition, had insensitivity to pain and a more general disorder affecting mood, sleep, and control of respiration. A disturbance of the opioid peptide system is postulated. naloxone reversed central analgesia, altered urine fluid and electrolyte excretion, modified the hormonal response to gonadotrophin-releasing and thyrotrophin-releasing hormones, and improved the auditory and visual reaction times. Specific opioid antagonists may have a therapeutic role.- - - - - - - - - - ranking = 1keywords = thirst (Clic here for more details about this article) |
9/11. Hypo-osmolal syndrome due to prolonged nausea.hyponatremia and hypo-osmolality developed in a 70-year-old patient. It was probably mediated by hypersecretion of antidiuretic hormone, which, in turn, was due to prolonged nausea and vomiting. Severe esophagitis was the cause of the nausea. The patient was not given large amounts of fluids intravenously, and it is likely that she continued to drink for nondipsetic reasons. In view of her medical history of neurosyphilis, the possibility of a disturbance in the mechanism of thirst regulation is discussed, but remains unproved.- - - - - - - - - - ranking = 1keywords = thirst (Clic here for more details about this article) |
10/11. Primary polydipsia. syndrome of inappropriate thirst.A patient with lifelong severe polyuria and polydipsia had normal serum antidiuretic hormone (ADH) levels and responded to water deprivation with a prompt increase in urine osmolality and maintenance of normal plasma osmolality (less than 290 mOsm/kg), despite extreme thirst. When treated with desmopressin acetate and allowed free access to water, she was able to reduce plasma osmolality below 270 mOsm/kg, and her compelling thirst disappeared. The disorder is interpreted to be the result of excessive fluid intake in response to a thirst stimulus that was not inhibited by normal plasma osmolality. This study indicates that osmoreceptor control of ADH secretion is normal. Continued administration of vasopressin has relieved the symptoms and has not resulted in water intoxication.- - - - - - - - - - ranking = 7keywords = thirst (Clic here for more details about this article) |
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