The clinical findings and neurologic outcome of 15 newborn infants with seizures due to hypocalcemia (HC) and hypomagnesemia (HM) admitted to St Louis Children’s Hospital are reported from Washington University, St Louis. Patients with perinatal asphyxia, cerebral hemorrhage, or other cerebral lesion were excluded. Seven infants had associated congenital heart disease, 2 were premature and 2 had hypoparathyroidism. None had nutritional abnormalities. Five died and 2 had neurologic abnormalities at follow-up. Prognosis was related more to associated medical conditions than the seizures. 
COMMENT. The associated congenital heart disease in almost 50% of these patients is remarkable and indicates the need for careful monitoring of serum calcium and magnesium levels before and after open heart surgery. Although hypocalcemic seizures caused by high phosphate content of cow’s milk-based infant formula is now a rare event, seizures related to low calcium and magnesium may be experienced in infants with parathyroid disorders, low birth weight, prematurity, fatty diarrhea, gastrointestinal disease, chronic nephropathy, and cardiac disease, in addition to infants with asphyxia, brain hemorrhage, and other cerebral lesions. In four infants with hypocalcemia treated personally at the Mayo Clinic, a history of cerebral anoxia or intracranial hemorrhage was reported at birth, and in one infant, an intracranial tumor was diagnosed. Seizures did not respond to intravenous calcium gluconate and a neurogenic hypocalcemia was postulated.