Serum ionized magnesium and calcium levels in adult patients with seizures

Abstract

Objective. Prior studies have been equivocal about whether or not serum levels of the divalent ions calcium and magnesium are altered during different types of seizures. Magnesium is a potential modulator of seizure activity because of its ability to antagonize the excitatory calcium influx through the N‐methyl‐D‐aspartate (NMDA) receptor. We hypothesize that serum ionized levels of calcium (Ca²⁺) and magnesium (Mg²⁺) would be altered significantly during certain types of seizures. Material and methods. A convenience sample of seizure patients presenting to an emergency department (ED) were enrolled in this prospective study. Novel ion‐selective electrodes were used to measure Ca²⁺ and Mg²⁺. Data were reported as mean values±standard deviations. Group comparisons were analyzed by ANOVA with post‐hoc testing using the Bonferroni, or the Fisher exact test, where appropriate, α = 0.05 (two‐tailed). Results. Forty‐nine patients with seizure and 32 healthy racially matched controls were included in the study. Seizure patients had a significantly (p<0.001) lower mean Mg²⁺, but not total serum Mg and a significantly (p<0.001) higher Ca²⁺/Mg²⁺ ratio than that in controls. Conclusions. We were able to show significantly lower Mg²⁺ and higher ionized Ca²⁺/Mg²⁺ ratios in seizure patients compared with a racially matched control group.

• Ionized calcium
• ionized magnesium
• seizure