PAEATHYROID GLANDS -697 



affected, rather than those of the pelvis. The disease may occasionally 

 occur in childhood (infantile osteomalacw) or in old age (senile 

 osteomalacia). 



For the diagnosis, the characteristic rontgenograms of the bones and 

 the adductor spasm in the thighs are helpful marks. 



McCrudden and Tales, who have studied the mineral metabolism in 

 osteomalacia, assert that there is a negative calcium balance. In the bony 

 tissues themselves, the calcium content is greatly decreased, though the 

 magnesium content and the sulphur content may be increased, owing to 

 the presence of much newly formed, but uncalcified, osteoid tissue. Zuntz 

 found an increase of the phosphoric acid of the feces in osteomalacia. ' 



It was probably the disturbed calcium metabolism in osteomalacia that 

 directed attention to a possible parathyrogenous origin of the disease. 

 Erdheim studied the parathyroid glands at autopsy in five cases of osteo- 

 malacia and found hyperplasia of the parathyroid secreting tissue in all 

 the cases except one. Enlargement may affect one gland only, though 

 in the other glands he could demonstrate, on histological examination, 

 multiple small hyperplastic foci. He attributed the hyperplasia of the 

 parathyroid tisue to an 'increased call upon the parathyroid function in 

 one form of osteomalacic intoxication. In a later publication Erdheim 

 described parathyroid changes, usually hyperplastic, sometimes neoplastic, 

 in still other cases of osteomalacia. 



The studies of Schmorl upon the parathyroid glands in four cases of 

 osteomalacia revealed no changes at all in three of the cases, though he' 

 admitted that in one case a tumor of the parathyroid was present. 



Erdheim's view has been supported by Strada, who found enlarge- 

 ment and tissue hyperplasia of the parathyroid glands in a single case of 

 osteomalacia, and by Bauer, who also observed an adenoma in one para- 

 thyroid gland and hyperplastic focal changes in the others in an osteo- 

 malacic cadaver. 



Though these pathological changes in the parathyroid glands in osteo- 

 malacia merit careful consideration, it would seem probable that osteo- 

 malacia is more closely related to diseases of the gonads than to disturb- 

 ances of parathyroid function. In favor of the gonadal relationship of 

 osteomalacia is the improvement that is said to follow oophorectomy and 

 castration in this disease. For reviews of the endocrin origin of osteo- 

 malacia, the reader is referred to the articles of Marinesco, Parhon and 

 Minea (1911), of L. Bernard (in Gilbert & Thoinet's System, 1912), 

 and of Sellheim (1913). 



PAGET'S DISEASE. In another rare osteopathy, namely, Paget's dis- 

 ease, known also as osteitis deformans, or senile pseudo rickets, a parathy- 

 rogenous origin has also been suggested. 



The disease rarely appears before the fiftieth year of life. It begins 

 insidiously with "rheumatic" or "neuralgic" pains in the bones and grad- 



