1/14. Primary infantile hypomagnesaemia: outcome after 21 years and treatment with continuous nocturnal nasogastric magnesium infusion.Primary infantile hypomagnesaemia is an infrequent cause of neonatal hypocalcaemic seizures but one that responds well to magnesium supplementation. We describe a 22-year-old male, first reported at 4 months of age, who is currently free of neurological deficit but has suffered from intermittent hypomagnesaemic tetany and chronic diarrhoea due to large oral magnesium supplements. Hypothesizing that modest hypercalcaemia might prevent the tetany, we conducted a trial of 5 microg/day 1,25(OH)2D3 over 5 days. Despite the resultant increase in calcium, he developed tetany with the reduction of magnesium intake and decline of serum magnesium from 0.63 to 0.39 mmol/l (normal >0.65 mmol/l). After 1,25(OH)2D3 was stopped and the parenteral magnesium injections suspended, 33% of his usual oral supplement was given instead by continuous nasogastric infusion and serum magnesium rose to 0.60 mmol/l. This regimen was better tolerated because of decreased gastrointestinal side-effects and freedom from parenteral injections. We observed that 1,25(OH)2D3 supplements do not promote magnesium retention nor does the resultant hypercalcaemia prevent hypomagnesaemic tetany. CONCLUSION: Continuous nocturnal nasogastric infusion may be considered in lieu of parenteral therapy in primary infantile hypomagnesaemia.- - - - - - - - - - ranking = 1keywords = tetany (Clic here for more details about this article) |
2/14. Latent tetany and anxiety, marginal magnesium deficit, and normocalcemia.The identification of marginal magnesium deficit, such as we have detected in a patient with anxiety, depression, and psychomatic complaints, is a difficult diagnostic problem. electromyography of a limb, rendered acutely ischemic either just before or after hyperventilation, can elicit latent tetany in this condition, as well as in calcium deficiency. We have demonstrated iterative electrical activity in our patient, whose magnesium deficit is attributable to renal wasting of magnesium. We have elicited similar patterns in several other patients, who had marginally low serum magnesium and who also exhibited weakness, anxiety, and psychosomatic disorders. This preliminary report suggests the need for further consideration of the possibility that chronic magnesium-deficit may contribute to the syndrome of latent tetany, psychosomatic complaints, and weakness.- - - - - - - - - - ranking = 1.5keywords = tetany (Clic here for more details about this article) |
3/14. Unusual clinical presentation and possible rescue of a novel claudin-16 mutation.CONTEXT: Familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) is caused by a dysfunction of Claudin-16 (CLDN16) and characterized by renal wasting of Mg(2 ) and Ca(2 ). OBJECTIVE: The objectives of this study were to study the clinical parameters in suspected FHHNC patients, identify mutations in the CLDN16 gene, and analyze molecular defects associated with the mutant protein. DESIGN, SETTING, AND PARTICIPANTS: CLDN16 genes from two siblings diagnosed with FHHNC were sequenced. Expression and characterization of the mutant protein in renal MDCK cells were studied. OUTCOME MEASURES: Standard urine and serum parameters to diagnose FHHNC were determined. Mutations in the CLDN16 gene were identified. The subcellular distribution of the mutant protein was analyzed by immunofluorescence microscopy. RESULTS: urine and blood analysis showed signs typical for FHHNC. One patient, in addition, presented with hypocalcemic tetany, a phenomenon so far not described for FHHNC. Both siblings carry a novel mutation in CLDN16, Y207X. The review of medical records showed that hypocalcemia is not uncommon in the early childhood of FHHNC patients. Expressed in MDCK cells, the Y207X mutant is not detected at tight junctions but instead is found in lysosomes and, to a lesser extent, the endoplasmic reticulum. Surface expression can be rescued by inhibiting clathrin-mediated internalization. CONCLUSIONS: We propose that mutations in CLDN16 are considered in childhood hypocalcemia. CLDN16 Y207X is transiently delivered to the plasma membrane but not retained and is rapidly retrieved by internalization. Inhibitors of endocytosis may provide novel therapeutic strategies.- - - - - - - - - - ranking = 0.25keywords = tetany (Clic here for more details about this article) |
4/14. A familial hypomagnesemia--hypercalciuria (Manz syndrome).We report a case of a rare inherited tubular disorder of linked transport of magnesium and calcium at the level of ascending limb of loop of henle, characterized by hypomagnesemia, hypercalciuria and nephrocalcinosis, known as "Manz syndrome," who presented with polyuria, nystagmus and recurrent episodes of tetany with radiological evidence of rickets and nephrocalcinosis.- - - - - - - - - - ranking = 0.25keywords = tetany (Clic here for more details about this article) |
5/14. keratoconus-tetany-menopause: the new association.This report describes the unusual case of 46-year-old white European woman who presented spontaneous keratoconus. This case suggests a new association: keratoconus-tetany-menopause. This can be explained by Thalasselis' syndrome, a syndrome showing a relation between keratoconus, magnesium (Mg) deficiency, type A behavior, and allergy. Furthermore, Thalasselis' syndrome integrates old and new theories. This report also suggests that the alteration induced by severe but reversible Mg deficiency at the intra- and extracellular levels, associated with metabolic and hormonal imbalances, may trigger the development of keratoconus. Clinical data which support this thesis are reported.- - - - - - - - - - ranking = 1.25keywords = tetany (Clic here for more details about this article) |
6/14. Primary hypomagnesemia with secondary hypocalcemia. Report of a case and review of the world literature.Primary hypomagnesemia with secondary hypocalcemia (PHSH) is a rare type of hypocalcemic disorder which occurs in early infancy and is clinically characterized by recurrent tetany and/or convulsion. In this paper, a male infant with PHSH who had frequent seizures at the age of 9 days is described. Besides PHSH, several illnesses in infancy are manifested by hypomagnesemia and hypocalcemia, i.e. transient neonatal hypomagnesemic hypocalcemia, congenital renal or hepatic insufficiencies, magnesium-losing nephropathy, combined impairments of intestinal absorption and renal reabsorption of magnesium. PHSH is to be differentiated from these illnesses by the demonstration of a combination of the following findings; hypocalcemia refractory to calcium but responsive to magnesium, continuous requirement for magnesium supplementation to maintain normocalcemia, lack of hypermagnesiuria and/or impaired intestinal absorption of magnesium. Twenty cases from the literature were found to exhibit these characteristics. The clinical, biochemical, and endocrine features of PHSH are summarized on the basis of a review of the data of these and the present case. No associated illness was known in the afflicted infants or mothers. Both male and female infants were afflicted at a male to female ratio of 15:6. Some siblings were afflicted but none of the parents or relatives. The onset of tetany and/or convulsion was between the 9th day and 4th month, which is later than that of other neonatal hypocalcemic illnesses. hypocalcemia was more pronounced than other infantile hypocalcemic illnesses. The role of the parathyroid hormone in the pathogenesis of hypocalcemia has been studied in several studies but no unifying concepts have yet been established.- - - - - - - - - - ranking = 0.5keywords = tetany (Clic here for more details about this article) |
7/14. Hypomagnesemia masking the appearance of elevated parathyroid hormone concentrations in familial pseudohypoparathyroidism.A 21-yr-old postpartum woman was found to be hypocalcemic and hypomagnesemic with a normal serum immunoreactive parathormone level (hypomagnesemic hypoparathyroidism). She was treated with calcitriol, calcium and magnesium. Two yr later the patient's son presented with tetany, hypocalcemia and the physical changes of pseudohypoparathyroidism. Subsequently, the patient's niece and nephew were also diagnosed with pseudohypoparathyroidism (low serum calcium, high serum phosphorus, high circulating immunoreactive parathormone). Re-evaluation of the patient on the above medical therapy showed a normal serum calcium, phosphorus and magnesium levels and an abnormally high serum immunoreactive parathormone level. The patient's magnesium supplementation was discontinued. No change in serum calcium, magnesium or parathormone levels resulted. We think that this patient demonstrates that hypomagnesemia can mask the laboratory presentation of pseudohypoparathyroidism by suppressing secretion of parathormone and further demonstrates that in pseudohypoparathyroidism the parathyroid gland retains its physiologic response to hypomagnesemia.- - - - - - - - - - ranking = 0.25keywords = tetany (Clic here for more details about this article) |
8/14. Electrolyte disturbances and cardiac failure with hypomagnesaemia in anorexia nervosa.A 32 year old woman with anorexia nervosa was admitted to hospital with severe hypocalcaemia and hypokalaemia that was refractory to replacement treatment but that responded immediately to an infusion of magnesium. She also had congestive cardiac failure that responded to magnesium replacement. The mild hypomagnesaemia found in this patient was responsible for the refractory hypocalcaemia. Minor deficiencies of magnesium may cause severe hypocalcaemia and hypokalaemia that are refractory to replacement treatment. Prompt replacement of magnesium may prevent prolonged tetany, cardiac arrhythmias, and heart failure.- - - - - - - - - - ranking = 0.25keywords = tetany (Clic here for more details about this article) |
9/14. tetany and myocardial arrhythmia due to hypomagnesaemia. A case report.An 11-year-old boy with acute intestinal obstruction presented with tetany, and developed myocardial arrhythmia during anaesthesia. The procedure was abandoned and the patient further investigated. He was found to have hypomagnesaemia and normocalcaemia. Intravenous magnesium sulphate corrected the tetany, and no further arrhythmia occurred during subsequent surgery.- - - - - - - - - - ranking = 0.5keywords = tetany (Clic here for more details about this article) |
10/14. Concurrent renal hypomagnesemia and hypoparathyroidism with normal parathormone responsiveness.A 24-year-old woman presented with clinical features suggesting hypoparathyroidism: tetany, basal ganglia calcification, and a history of a seizure disorder. hypocalcemia was present on admission despite therapy with calcium and vitamin d. Hormonal evaluation revealed undetectable parathormone levels and a normal cyclic amp and phosphaturic response to parathormone infusion, suggesting the diagnosis of idiopathic hypoparathyroidism. Additional testing, however, revealed hypomagnesemia and elevated urinary magnesium levels. Normomagnesemia could not be consistently achieved despite oral magnesium administration. When the serum magnesium level was temporarily normalized via intravenous magnesium supplementation, parathormone levels rose into the normal range. These data indicate that the patient's hypomagnesemia was most likely due to renal magnesium loss. The normalization of her parathormone level during magnesium replenishment, along with the parathormone infusion data, suggests that this patient's hypomagnesemia was responsible for decreased parathormone synthesis and/or secretion, while target tissue responsiveness to parathormone was maintained.- - - - - - - - - - ranking = 0.25keywords = tetany (Clic here for more details about this article) |
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