Endocrine Abstracts

A 41 year old woman presented with a 4 month history of oropharyngeal spasms precipitated by eating, yawning or talking. Such manouvres caused her to fear for her life due to profound choking and 'going blue';as a result she had stopped eating. On direct questioning she complained of circumoral tingling, paraesthesia and carpopedal spasm. She described profuse diarrhoea over the preceding year and had lost 15 kilograms. She was taking no drugs to interfere ith calcium homeostasis. Chvostek's and Trousseau's signs were negative.
Calcium was 1.26, repeated 1.56(2.10-2.60) millimols per litre, phosphate 1.83(0.80-1.4) millimols per litre, magnesium 0.24(0.65-1.05)millimols per litre, PTH 37.2(12.0-72)nanograms per litre, albumin 38(34-51)grams per litre. Renal function was normal, ECG showed normal QT interval. Biochemistry suggested hyomagnesaemia-induced hypocalcaemia.
Due to the severity of symptoms she was admitted for IV magnesium infusions resulting in a dramatic symptomatic improvement within 24 hours. Calcium corrected with correction of serum magnesium and she was commenced on long term oral magnesium supplements. She remains well,normocalcaemic and normomagnesaemic. Her diarrhoea continues and is under investigation but is likely due to malabsorption secodary to bacterial overgrowth, a recognised feature of systemic sclerosis. [BR>Hypomagnesaemia-induced hypocalcaemia does not usually cause the severity or the nature of the symptoms herein. Neuromuscular hyperexcitability is a feature of hypomagnesaemia when magnesium concentrations fall below 0.5 millimols per litre, and we propose that the choking experienced reflected spasm of the oropharynx and oesophagus. The temporal improvement seen with correction of magnesium/calcium would support this. Two similar case reports exist. Dysphagia is not a recognised feature of hypocalcaemia and may be due to magnesium deficiency per se since symptoms rapidly resolved following magnesium infusion prior to correction of calcium.