Neonatal convulsions associated with primary disturbance of calcium, phosphorus, and magnesium metabolism.

Cockburn, F., Brown, J. K., Belton, N. R., and Forfar, J. 0. (1973). Archives of Disease in Childhood, 48, 99. Neonatal convulsions associated with primary disturbance of calcium, phosphorus, and magnesium metabolism. The biochemical relations in 75 newborn infants suffering from convulsions considered to be due to a primary disturbance of mineral metabolism have been studied. Hypocalcaemia was present in 92% of cases, hypomagnesaemia in 53%, and hyperphosphataemia in 64%. In nearly 80% of cases combinations of biochemical disturbance were present, the commonest being hypocalcaemia/hypomagnesaemia/ hyperphosphataemia; hypocalcaemia/hyperphosphataemia; and hypocalcaemia/ hypomagnesaemia. Isolated hypocalcaemia occurred in 19% of cases but isolated hypomagnesaemia in only 3%. Changes in the concentrations of calcium, phosphorus, and magnesium in the CSF mirrored those in the blood but were less pronounced. Osmolality in blood and CSF was the same in normal and in convulsing infants and there was no difference between these two groups of infants. There are wide differences in the osmolality of breast milk on one hand and most evaporated milk feeds on the other. In terms of associated neurological findings, infants suffering from convulsions due to a primary disturbance of mineral metabolism show a distinctive but not wholly exclusive clinical pattern. In therapy magnesium appears to have an important role in rectifying not only hypomagnesaemia but also hypocalcaemia. The prognosis in convulsions due to primary disturbance of mineral metabolism is good.