1/8. 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) |
2/8. 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) |
3/8. Inappropriate secretion of antidiuretic hormone, polydipsia and hypothalamic calcifications.We studied a 41 year old patient who had pathologic fluid intake of 10 1/day together with syndrome of inappropriate antidiuretic hormone. Imaging studies revealed a lesion of the anterior wall of the third cerebral ventricle. A review of relevant literature indicated several different disturbances by which alterations of thirst, vasopressin-secretion and abnormalities of anterior third ventricle may be associated. The present case presents an unusual and potentially dangerous combination in this spectrum of changes.- - - - - - - - - - ranking = 1keywords = thirst (Clic here for more details about this article) |
4/8. Hypothalamic disease in association with dysgenesis of the corpus callosum.We describe two cases of dysgenesis of the corpus callosum demonstrated by magnetic resonance. The first patient presented with chronic hyponatraemia. Investigation demonstrated re-setting of the osmoreceptor and thirst centres. The calculated threshold for arginine vasopressin (AVP) release was reduced at 252 mosmol/kg while severe thirst was perceived at a plasma osmolality of 260 mosmol/kg. insulin-induced hypoglycaemia produced an exaggerated AVP response. The second patient presented with hypothermia. The calculated threshold of AVP release was 296 mosmol/kg with increased sensitivity of AVP response to hypertonic saline. The plasma AVP response to insulin-induced hypoglycaemia was absent. Both cases had normal anterior pituitary function and psychological assessment showed a similar prefrontal defect. Specific tests of callosal function were normal. These cases illustrate the importance of undertaking complete neuroradiological assessment of cases of unexplained hypothalamic disease regardless of the age of presentation to avoid overlooking this rare congenital association.- - - - - - - - - - ranking = 2keywords = thirst (Clic here for more details about this article) |
5/8. Recurrent pregnancy-induced polyuria and thirst due to hypothalamic diabetes insipidus: an investigation into possible mechanisms responsible for polyuria.A young patient developed hypothalamic diabetes insipidus due to histiocytosis in infancy and was satisfactorily treated with Pitressin. As a teenager she no longer had thirst or polyuria after treatment was stopped. These symptoms only returned during her two pregnancies. When non-pregnant her urine output was 1.7-2.0 1/24 h, basal plasma osmolality 288-290 mOsm/kg, and during pregnancy 24 h urine volume was 4.5-5.21, plasma osmolality 278-280 mOsm/kg. Studies on osmoregulation of thirst and AVP release, and on renal sensitivity to the V2 agonist desmopressin and endogenous vasopressin were performed in pregnant and non-pregnant states. She had no circulating antibodies to AVP, and the effect of pregnancy-associated vasopressinase was eliminated. Results showed lowered basal plasma osmolality and osmolar thirst threshold in pregnancy but no failure of the renal concentrating mechanism. plasma AVP concentrations after osmotic stimulation were lower in pregnancy. We propose that she developed thirst and polyuria during pregnancy because of lowering of her osmolar thirst threshold to plasma osmolalities which caused her to drink sufficient quantities of fluid to further reduce AVP secretion. We cannot exclude, however, the possibility that there was increased clearance of circulating AVP.- - - - - - - - - - ranking = 9keywords = thirst (Clic here for more details about this article) |
6/8. D-lactic acidosis simulating a hypothalamic syndrome after bowel bypass.A 36-year-old man had one year of periodic symptoms suggestive of episodic hypothalamic dysfunction: hypersomnia, thirst, ravenous hunger and gorging behavior, pallor, and irritability. However, neuroendocrine testing proved normal. A mild transient acidosis at the onset of his attacks and a history of bowel bypass five years earlier prompted metabolic screening. Markedly increased urinary D-lactic and phenolic acids were present, as were intermittent elevations of plasma D-lactic acid during two symptomatic episodes. Prompt and sustained clinical remission coincided with disappearance of abnormal organic acid excretion during oral antibiotic therapy. D-Lactic acidosis must be considered in the differential diagnosis of otherwise unexplained neurological syndromes, particularly in patients with altered bowel anatomy.- - - - - - - - - - ranking = 1keywords = thirst (Clic here for more details about this article) |
7/8. Surgical syndromes of the hypothalamus.The clinical syndromes described with lesions of the hypothalamus are summarized in Table 9.5-9.7. The anterior hypothalamic syndrome consists of insomnia and loss of thirst regulatory mechanisms. In occasional larger lesions which interrupt the output from the supraoptic and paraventricular nuclei, diabetes insipidus has been noticed. In the tuberal region of the hypothalamus the most prominent findings are those that are caused by the disruption of the final common pathway to the pituitary. This results in endocrinopathy, most often the syndrome originally reported by Frohlich, with failure of sexual maturation and obesity. In the tuberal region, differences between lesions of the medial and lateral portions are quite marked. Medial lesions result in obesity while bilateral lesions result in anorexia and emaciation. The diencephalic syndrome of infancy with it's severe emaciation in young years and obesity in later years clearly indicates a different organizational pattern in the neonatal hypothalamus. Emotional disorders may be seen with lesions either in the medial or lateral hypothalamus at the tuberal level. Finally, in the posterior hypothalamic region, which includes the greatest effector apparatus, hypersomnia, apathy, and poikilothermia have been reported. Emotional disturbances and the Wernicke-korsakoff syndrome also seemed to be associated with lesions in this area. The hypothalamus remains the single most important integrator of vegetative and endocrinologic regulation of the body. Cushing said of the hypothalamus, "here in this hidden spot, almost to be covered with a thumb nail, lies the very main spring of primitive existence: vegetative, emotional and reproductive".- - - - - - - - - - ranking = 1keywords = thirst (Clic here for more details about this article) |
8/8. Idiopathic hypothalamus-pituitary dysfunction: review of five cases.We describe 5 children, 4 girls, aged 4-14 years with evolving hypothalamic-pituitary dysfunction. They had presenting features, isolated or combined, of polyuria and polydipsia (n = 3), weight gain and hyperphagia (n = 3), and growth failure (n = 1). During periods of 1-5 years per child, the following abnormalities developed: diabetes insipidus (n = 5), osmoreceptor dysfunction (hypernatraemia with absent thirst) (n = 3), hyperprolactinaemia (n = 3), growth hormone (GH) deficiency (n = 4, of whom 3 had normal linear growth), ACTH deficiency (n = 2), TSH deficiency (n = 2) and precocious puberty (n = 1, female). In 2 patients, high-resolution CT scans and MRI showed structural lesions of the hypothalamus 1.5 and 3.5 years after presentation. These were inaccessible and not biopsied. Scans in the remainder were normal. In conclusion, weight gain, impaired thirst, and hyperprolactinaemia were early features of evolving hypothalamic-pituitary dysfunction, and occurred with diabetes insipidus, accompanied by progressive anterior pituitary deficiencies. Pituitary hormone replacement with clinical and neuroradiological surveillance is important in any child with symptoms suggestive of an evolving hypothalamic lesion.- - - - - - - - - - ranking = 2keywords = thirst (Clic here for more details about this article) |