Relation of Parathyroid Glands to Hyperirritability. 69 



during a period of 10 days following operation. One showed mod- 

 erate anodal hyperirritability during a period of 7 days following 

 operation. One showed no electrical change during 1 1 days after 

 operation. The removal of one parathyroid resulted in only 

 moderate lowering of the anodal reactions. 



Of 8 dogs with 2 parathyroids removed none developed 

 frank tetany. Two showed marked electrical hyperirritability to 

 K.C., A.C., A.O. and K.O. during 25 days following operation. 

 Two showed marked anodal irritability during 13 days and 10 

 months respectively after operation. Four showed very slight 

 anodal irritability during periods of from 1 to 4 weeks after opera- 

 tion. Electrical irritability of varying degree follows injury to 

 or removal of 2 parathyroid glands. 



Of 2 dogs with 3 parathyroids removed neither developed 

 frank tetany. Both gave prompt and marked anodal irritability 

 with occasional low response to K.O. Observations were con- 

 tinued for 36 days after operation. 



Of 4 dogs subjected to complete thyroparathyroidectomy at 

 one operation, two gave complete hyperirritability on day follow- 

 ing operation and developed tetany two days later. One de- 

 veloped marked anodal irritability with tetany the following day. 

 One, for 46 days, showed neither electrical nor other symptoms of 

 tetany. 



Of 7 dogs having part of their parathyroid tissue removed at 

 one time, and the remainder later, 5 developed prompt and com- 

 plete electrical change and frank tetany. One showed no hyper- 

 irritability but died of tetany in six days after operation. One 

 showed complete galvanic reactions but died on the sixth day 

 without other signs of tetany. Prompt and complete hyper- 

 irritability, followed in from one to two days by severe tetany, 

 resulted in the removal of all parathyroid glands. 



5. Electrical change was noted in from 5 to 48 hours after 

 operation. The promptness and severity of its development de- 

 pended to a considerable degree upon the amount of parathyroid 

 tissue removed. 



6. In all dogs developing frank tetany the electrical diagnosis 

 was established from 1 to 3 days before other symptoms appeared. 

 Lesions which failed to produce tetany were usually accompanied 



