To the Editor.
—In the September 1990 issue of the Archives, Kaplan et al1 discount the use of magnesium sulfate for eclamptic seizures for two reasons: first, magnesium sulfate has not been shown to be as effective as phenytoin in a controlled clinical trial, and second, "magnesium sulfate has no anticonvulsant properties. It could only be argued in a more general sense that... magnesium sulfate might prevent secondary seizures." While agreeing wholeheartedly with their first point, I would like to suggest that the experimental basis for a possible anticonvulsant action of the magnesium ion (Mg++), as well as for its antiepileptic properties, is stronger than the authors allow.Hippocampal slice models of epilepsy have shown that the N-methyl-d-aspartate (NMDA) subtype of glutamate receptor, which is the type blocked by Mg++, is involved in epileptogenesis (ie, the generation of a state prone to seizurelike uncontrolled discharges). In
Brorson JR. Magnesium Suppresses Seizurelike Discharges in Cultured Neurons. Arch Neurol. 1991;48(7):677. doi:10.1001/archneur.1991.00530190019005