THREE communications pertaining to symmetric cerebral calcification were publishedby Camp, Love, Eaton and Haines (2, 3, 5) in 1938 and 1939, and a thesis on this subject was prepared by one of us (Eaton (1)). In these communications were described some of the roentgenographic (Fig. 1a and b) observations in seven cases and the data obtained at necropsy in one of these cases. The point was emphasized that symmetric cerebral calcification was often associated with spontaneous parathyroid insufficiency, and it was our opinion that the changes in the brain resulted from parathyroid insufficiency. This hypothesis could, of course, be somewhat strengthened by the finding of symmetric cerebral calcification in a case of postoperative parathyroid insufficiency, but this we had been unable to do at the time of our last publication. Failure to find such an occurrence may have been due in part to failure in earlier years to make roentgenograms of the skull in our cases in which parathyroid insufficiency followed thyroidectomy, and in part, also, to the fact that whereas the condition of most patients who have postoperative parathyroid insufficiency is properly diagnosed and treated early, many patients with spontaneous parathyroid insufficiency are untreated for many years. It is generally true also that, in most cases, spontaneous parathyroid insufficiency is of severe degree, whereas a larger number of those patients who acquire the deficiency after operation have it to a less severe degree.