The total and diffusible calcium of serum and the calcium of cerebrospinal fluid in human cases of hypocalcaemia and hypercalcaemia

Abstract

Analyses of serum for total and diffusible Ca, protein, and inorganic P, and of cerebrospinal fluid for Ca, were made in human diseases including tetany, nephritis, and hyperparathyroidism. Normally the Ca of cerebrospinal fluid is equal to the diffusible serum Ca, but when the diffusible Ca rises or falls the Ca of cerebrospinal fluid fails to follow. In hypocalcemia associated with low serum-protein and normal inorganic phosphate the diffusible serum Ca is normal. In the hypocalcemia of uremia, diffusible Ca may be normal or low, and the relation between diffusible Ca, protein, and phosphate is not constant, though marked phosphate retention is associated with low total and diffusible Ca figures. In tetany the diffusible Ca is low and the relation of diffusible to total Ca variable. In hyperparathyroidism the diffusible Ca rises, and the normal ratio of diffusible to total is maintained. (Diffusible Ca was determined by ultrafiltration through collodion sacs at a pressure of 150 mm. Hg.).