PARATHYROID GLANDS 681 



condition only and thus make tetany a part of the more comprehensive 

 spasmophilic group, whereas others believe that all the members of the 

 spasmophilic group of conditions belong to tetany and, perhaps, to hypo- 

 parathyrpidism. The tendency toward the latter view seems to be 

 increasing. 



2. Conditions (Other than Tetany) that May Simulate 

 the Motor Pareses Sometimes Seen in Tetany 



Though, in tetany, hyperkinetic signs are much more common than 

 pareses, still undoubted cases of tetany exist in which there is marked 

 weakness, either local or general, of the muscles. When these pareses of 

 tetany are accompanied by fibrillary or fascicular twitchings, confusion 

 with other diseases is easily possible. 



Poliomyelitis. If the motor pareses involve the extremities and are 

 accompanied by fibrillary twitchings, poliomyelitis will of course be 

 thought of in making a differential diagnosis, though the phenomena may, 

 in reality, be due to tetany. If, on the one hand, one searches for other 

 tetany signs and, on the other, makes a study of the cerebrospinal fluid, 

 there will be no difficulty in distinguishing between the two diseases. 



Progressive Muscular Atrophy. This form of muscular atrophy with 

 muscular paresis, whether it affect the muscles of the extremities or those 

 in bulbar domains, might, in rare instances, be confounded with the motor 

 pareses that sometimes follow tetany. In some cases of tetany, as we have 

 seen, the paretic phenomena entirely overshadow the hyperkinetic phe- 

 nomena. The latter may even be wholly absent. In tetany, however, there 

 is no real muscular atrophy, and there is an increase of the galvanic ex- 

 citability of the motor nerves, whereas this is absent in progressive central 

 muscular atrophy. 



Peripheral Neuritis. Tetany has, occasionally, been confused with 

 alcoholic and other forms of polyneuritis, which it sometimes closely re- 

 sembles in its sensory phenomena and in the depression of the deep re- 

 flexes. The anamnesis and the careful search for tetany signs will dif- 

 ferentiate between the two diseases. 



Muscular Dystrophies. In some cases of tetany there is marked paresis 

 of the lumbar muscles and of the muscles about the hips, the patients ex- 

 hibiting a wobbling gait very much like that seen in some forms of mus- 

 cular dystrophy. Here> again, an analysis of the anamnesis, a study of the 

 heredity and of the familial conditions, the consideration of the time of 

 appearance of the phenomena, the examination of the trophic condition of 

 the muscles (atrophies, pseudohypertrophies), and the weighing of the 

 results of the electJrical examination, will give adequate differential 

 criteria. 



