TETANY
Authors: Lamberg B.-A. , Gordin R. , Kuhlbäck B. , Björkenheim G. 
Published: December 2008

The purpose of this study was to investigate the tetanic predisposition and certain aspects of calcium metabolism in cases showing a vague disease picture, characterized mainly by the presence of visceral pains of unknown etiology, headaches, various neurovegetative symptoms, etc. The development of typical carpal cramps in Trousseau's or Trousseau-von Bonsdorff's test was regarded as a sign of a tetanic predisposition.

In a total of several hundred cases of the type described above in which provocation tests were performed, the response was positive in 97. Spontaneous tetanic attacks occurred in 38 cases. On the basis of the calcium level the cases were classified in hypocalcaemic (20) and normocalcaemic (77). The latter were further divided into the following subgroups: cases with a history of thyroidectomy (7), neurogenous cases in which the disease picture was dominated by neurovegetative symptoms (26), idiopathic (42) and gastro-enterogenous (2).

In addition, 18 cases of postoperative hypocalcaemic hypoparathyroidism were investigated in which the provocation test was positive in 16 and negative in two, notwithstanding a low serum calcium level. In this group spontaneous attacks occurred in 10 cases.

Furthermore, in studies concerning calcium metabolism 41 control cases were used. In addition, Trousseau-von Bonsdorff's test was performed on 40 healthy subjects, all of whom responded negatively.

The present investigation included determination of serum calcium and serum phosphorus and the excretion of calcium and phosphorus in the urine, intravenous calcium tolerance tests, parathyroid hormone tolerance tests and short-term AT 10 treatment for test purposes.

This study was aided by a grant from the State Commission for Natural Sciences.

The calcium excretion was less than 50 mg in practically all cases showing hypoparathyroidism, but also in one control case. In addition, an excretion of less than 50 mg a day was observed in one case of sprue and in one case of idiopathic tetany.

The responses to the intravenous calcium tolerance test showed a wide variation, and it was concluded that this test is inadequate as an ordinary clinical routine test.

The parathyroid hormone tolerance test gave a pathological response twice in one patient with postoperative hypoparathyroidism and in one case with normocalcaemia and a history of thyroidectomy.

In many cases AT 10 therapy brought about a rapid and marked increase in calciuria, an excretion of as much as 800 mg a day being sometimes noted, although the changes in the blood were slight. This discrepancy in the response is emphasized and checking of the excretion of calcium, in addition to checking of the blood calcium, during AT 10 therapy is recommended.

The clinical significance of the tetanic syndrome is discussed. In many cases the syndrome manifests itself only occasionally and under certain circumstances, but in others it may be grave enough to be called a disease. Patients with postoperative hypoparathyroidism constitute a separate group, in which the pathogenetic background seems to be clear. But it should be emphasized that there also are cases of postoperative hypoparathyroidism in which no signs of a tetanic predisposition can be elicited even by provocation. Latent tetany often seems to be associated with a vague disease picture. For the detection of a tetanic predisposition Trousseau-von Bonsdorff's test is very valuable.

It may be added that during intravenous administration of calcium, exogenous 32P was found to be excreted in the urine in a different way than endogenous phosphorus.