PATHOGENESIS OF TETANY 2O$ 



"Thereby is found a partial unloading of the ganglion-cells, although 

 apparently not in very great degree, so that the hyperexcitability is still 

 present after the attack. This conception explains why at one time an 

 occasioning factor may call forth a spasm, while a short time afterward it 

 is inactive, perhaps becoming active again on the next day, and why the 

 spontaneous condition of hyperirritability in tetanics is subject to such 

 significant rapid change. This behavior may be observed especially beauti- 

 fully on animals that have been parathyroidectomized ; these dogs and cats 

 may be the victims of the most severe spasms, and yet a few hours later may 

 play as vivaciously as ever. Only the exact investigation of the electrical 

 and mechanical hyperexcitability now affords knowledge as to the latent 

 tetanic condition. This view also makes appear intelligible the fact that 

 certain nerve territories that have immediately met with numerous irrita- 

 tions (peripheral neurons) are especially preferred, and that the conditions 

 of irritability in the different nerve territories are of different strengths, and 

 may be subject to considerable change. 



"In what relation do the parathyroids stand to the hyperexcitability 

 or to the condition of excitability of the ganglion-cells? 'Everywhere where 

 excitation is, is also present inhibition' (Meltzer). According to Bechterew, 

 the inhibitory processes are to be regarded as an indispensable protective 

 arrangement of the central nervous system. The normal -condition of 

 irritability of the ganglion-cells is guaranteed only by the finest regulation of 

 increase of activity [Forderung] and inhibition. Falta and Rudinger have 

 expressed the opinion that the parathyroid glands exercise inhibitory influences 

 on the ganglia by a hormone, and that the diminution or complete with- 

 drawal of this inhibition leads to an abnormal loading of the cell with energy. 



"We do not know anything more intimately as to the action of this 

 hormone. It is not impossible, however, to bring this hypothesis into com- 

 bination with that developed by MacCallum and Vogtlin, by our following 

 the assumption of these authors that the parathyroid glands influence the 

 calcium metabolism in the central nervous system by means of a hormone. 

 The hormone of the parathyroid glands might thus be regarded as an as- 

 similatory hormone, with the withdrawal of which there occurs loss of cal- 

 cium in the ganglion-cells and hyperirritability of these." 



The details up to the present confine themselves to the mechanism by 

 which insufficiency of the parathyroids leads to tetany; they set forth that 

 all forms of tetany depend on an absolute, or at least, a relative insufficiency 

 of the parathyroids. The different causes of parathyroid insufficiency 

 will be discussed later, with the exposition of the different forms of tetany 

 and the pathological anatomy. 



We shall add a few words as to the relation of myotonia, epilepsy and 

 eclampsia to tetany. The occurrence in tetany of symptoms similar to 

 those of myotonia is, as already mentioned, not rare. The fact that they 



