Plasma trace element levels in infants and children with refractory epilepsies

ABSTRACT

To study the effect of long term use of antiepileptic drugs [AED] on plasma trace elements and the evolution of refractory seizures. Twenty three children were chosen to have persistent disabling seizures despite trials of all major anticonvulsants, alone and in combination, and with the highest doses the patient can tolerate. They were 13 males and 10 females with age range 2-14 years. Preliminary investigations were done to exclude cases with secondary seizures and those with low plasma levels of antiepileptic drugs. All of the patients were subjected to thorough clinical and neurological evaluation, neuroimaging studies and assessment of plasma trace elements levels [Selenium, Copper, Magnesium and Zinc] using the atomic absorption spectrophotometry. According to the clinical and electroencephalographic patterns, the selected patients were subdivided into cases with partial seizures including those with secondary generalization [group I] and cases with primary generalized seizures [group II]. Ten healthy children of matched age and sex were tested for plasma trace elements as a control group. Then after all of the patients were supplemented with trace elements medications [3-5ug/kg/day related to selenium] for three weeks and the response was followed up for 12 weeks. Plasma trace elements showed no significant differences between the 2 patients' groups [unpaired t-test, p>0.05]. Meanwhile, one way ANOVA showed significantly lower levels of selenium in all of the patients compared to the controls [p<0.001]. Correlation studies revealed a highly significant negative correlation between selenium levels and duration of AED [r = -0.81 and p=0.00]. Response to trace elements therapy was variable complete response [cessation of seizures] in 25% of group I vs 33% of group II, partial or no response in 75% of group I vs 67% of group II. Response to trace elements has no significant associations with the type of sex, frequency and severity of seizures. The long-term use of AED may lead to trace element deficiencies with subsequent neuronal damage and evolution of resistant states. We recommend trace element supplementation especially selenium in patients under long term use of antiepileptic drugs