658 



LEWELLYS F. BAKKER 



heightens the irritability of the peripheral nerves may, they think, give 

 rise to this interesting symptom complex. 



On reviewing the bibliography of forced breathing, Grant and Goldman 

 found a number of 'observations by other investigators of symptoms sug- 

 gestive of tetany during the process. Thus, Vernon (1909) noticed, on the 

 production of prolonged apnea in himself, tonic rigidity of the muscles of 

 the hands and even temporary paralysis. Yandell Henderson (1909) 

 made the same observation as Vernon during voluntary hyperpnea in sev- 

 eral subjects, and even more frequently heard complaints of prickling sen- 

 sations in the extremities, or in the face and the entire body ; in one in- 

 stance a "shivering fit," like that of a chill, involved all the muscles of the 



Fig. 15. Attack of tetany in a patient suffering from Paroxysmal Hyperpnea 

 during convalescence from epidemic encephalitis. (After L. F. Barker and T-. P. Sprunt, 

 1021.) 



body. And Hill and Flack (1910) reported "feelings of numbness in the 

 limbs," a "spastic state of the hands," "twitching of the facial muscles," a 

 sensation as though the mouth were "pursed up in the form of an 0, so 

 that speaking became difficult," and contractions of the lid closing muscles 

 of the eyes, in subjects of voluntary hyperpnea. None of these investi- 

 gators, however, identified these paresthetic and spastic phenomena with 

 the symptoms of tetany ! 



It is just possible that the tetany observed by Stein (1916) in patients 

 under slight anesthesia may have been due to overventilation. 



It is interesting that two Canadian investigators (Collip and Backus) 

 also observed the occurrence of tetany during forced respiration and that 

 their paper was published in the American Journal of Physiology a few 

 months before the paper by Grant and Goldman appeared. 



Following upon these studies by the experimental physiologists, Barker 







