PARATHYROID GLANDS 673 



The tonic spasms are a constant symptom in the acute stages of tetany, 

 but the form of the spasms may not be typical. Many variations (in atti- 

 tude, duration, and severity) from normal type are met with. Thus, in- 

 stead of the typical obstetrical hand with flexion of the elbow, the elbow 

 may be extended, and the fingers may form a fist or a claw, or may be 

 spread apart instead of being strongly adducted. Again, in the lower 

 extremities, instead of the typical extension at the knee, there may be 

 flexion ; and instead of plantar flexion and supination of the foot, there may 

 be dorsal flexion at the ankle. The duration of the spasms is, in turn, also 

 exceedingly variable. And as to severity, instead of the typical violent 

 attack, the spasms may be so mild that the patients do not mention them, 

 but recall them only when asked specifically about them ; in such instances, 

 the patients complain rather of the paresthesias and the pain than of the 

 spasms. In many patients the attacks of spasm appear only under the 

 influence of some releasing factor (muscular overexertion, psychic trauma, 

 infection, intoxication, pregnancy, menstruation, dilatation and curetting 

 of the uterus, injection of tuberculin, acidosis, alkalosis, etc.). 



One of the most constant phenomena in tetany, whether manifest or 

 latent, is a positive finding on testing for increased mechanical excitability 

 of the nerves, especially Chvostek's sign, or the facial phenomenon follow- 

 ing a tap in front of the ear or below the zygoma. Though this sign may be 

 positive in conditions other than tetany, noticeably in tuberculosis, epi- 

 lepsy, hysteria, and pellagra, still, when it is present in a marked degree, it 

 is one of the most important clews for diagnosis and should lead one to the 

 making of a series of careful tests, the results of which will be decisive. 

 Chvostek has asserted that the facial phenomenon is the "finest reagent we 

 possess for detecting the existence of a functional disturbance of the para- 

 thyroid glands." It is exceedingly rare that, in tetany, the facial phenome- 

 non is absent on repeated testing. It is the most constant and often the 

 only symptom demonstrable in the latent periods of tetany. If a light tap, 

 or stroking with the finger tip, over the trunk of the facial nerve calls forth 

 contractions in the whole of the same side of the face, one can be sure that 

 tetany exists. Even with Chvostek II, a positive finding is rare in any 

 condition other than tetany. On a Chvostek sign of the third grade 

 (Chvostek III) too much stress should not be laid, though it may excite in 

 the mind of the examiner the suspicion that a slight functional disturbance 

 of the parathyroid glands may exist. 



Next to the increased mechanical excitability of the nerves the most 

 important single test for tetany is the examination for increased electrical 

 excitability of the motor nerves (Erl's phenomenon). When, on testing 

 with the galvanic current, there is early response to anodal opening con- 

 traction and to cathodal opening contraction, and especially when anodal 

 opening tetanus and cathodal opening tetanus are easily demonstrable, we 



