[Tetany as a sole manifestation in a patient with Bartter's syndrome and a successful treatment with indomethacin].

37 year-old man presented to our clinic because of tetany that occurred during driving a car in the morning. He had no anorexia, chronic diarrhea or vomiting. He was normotensive and no edema was noted. On neurological examination, he was rather apprehensive and Trousseau sign was mildly positive. No muscle weakness was noted except for the moderate atrophies of bilateral anterior tibial muscles as a sequela of Guillain-Barré syndrome that he suffered at the age of 7. The results of laboratory studies included hypokalemia, metabolic alkalosis, hyperuricemia, increased plasma renin activity, increased plasma aldosterone concentration, reduced pressor response to infusion of angiotensin II. Based on these clinical and laboratory findings, the diagnosis of Bartter's syndrome was made. As far as we know, it is extremely rare that Bartter's syndrome manifests tetany alone as in the present case. The exacerbation of preexisting alkalosis by hyperventilation during driving might be the cause of tetany. Tetany was easily provoked by hyperventilation, during which serum ionized calcium remained in normal level despite the exacerbation of alkalosis. The results suggest that alkalosis per se can cause tetany in Bartter's syndrome. Indomethacin, 75 mg daily, effectively prevented tetany from recurring for nearly 4 years without any side effect.