NATURAL-HISTORY AND OUTCOME OF NEONATAL HYPOCALCEMIC AND HYPOMAGNESEMIC SEIZURES

The clinical characteristics and neurologic outcome of 15 newborn infa nts with seizures due to hypocalcemia and hypomagnesemia have been stu died with careful exclusion of those patients who had other possible e tiologies for seizures. Associated diagnoses included severe congenita l heart disease in 7 of 15 (47%) patients. Possible causes for this as sociation with congenital heart disease include a forme fruste of DiGe orge syndrome, hypocalcemia and hypomagnesemia due to critical illness , and subtle embolic cerebral ischemia. In contrast with previous stud ies, no abnormalities of formula milk feeding were observed. Five pati ents (36%) died of causes unrelated to seizures. Follow-up in 8 of 9 p atients who had no cerebral insults other than neonatal seizures at a mean age of 57.8 +/- 10.5 months found neurologic abnormalities in 2 ( 22%), both with an endocrine etiology for hypocalcemia. We conclude th at infants with severe congenital heart disease should be investigated for hypocalcemia and hypomagnesemia. Previous observations of a unive rsally favorable neurologic outcome in newborns with hypocalcemic or h ypomagnesemic seizures may be valid for those who have a nutritional e tiology for the metabolic disturbance but are less relevant to the cur rent population in whom hypocalcemia or hypomagnesemia due to errors i n formula milk feeding is seldom observed. In this group, neurologic p rognosis may be more related to associated medical conditions.