Role of folic acid depletion on homocysteine serum level inchildren and adolescents with epilepsy and different MTHFR C677T genotypes.

Homocysteine (Hcy) is a sulfur-containing amino acid involved in methionine metabolism. An elevated total plasma Hcy concentration (tHcy) is a risk factor for vascular disease. The present study aimed to assess the role of antiepileptic drugs (AEDs) and C677T methylenetetrahydrofolate (MTHFR) polymorphisms on tHcy in pediatric patients with epilepsy treated for at least 6 months with various treatment regimens protocols including the newer AEDs. The study group was recruited from children and adolescents with epilepsy followed up in the Child Neuropsychiatry Clinic of the Second University of Naples, between January 2007 and March 2008. Inclusion criteria were: (1) patients with epilepsy, treated with one or more anticonvulsant drugs for at least 6 months; (2) age between 2 and 16 years. Plasma tHcy concentrations were considered elevated when they exceeded 10.4 mmol/L, and folate concentrations <3 ng/mL were considered deficient. Serum vitamin B12 levels were considered normal between 230 and 1200 pg/mL. The study group was composed of 78 patients (35 males, 43 females), aged between 3 and 15 years (mean 8.9 years). Thirtyfive patients were taking AED monotherapy, 43 polytherapy. Sixty-three healthy sex- and age-matched children and adolescents served as controls. The mean tHcy value in the patient group was higher than the mean value in the control group (12.11 7.68 mmol/L vs 7.4 4.01 mmol/L; p < 0.01). DNA analysis for the MTHFR C677T polymorphism showed the CT genotype in 46%, CC in 35% and TT in 17.8% of cases. Decreased folic acid serum levels significantly correlated with increased tHcy levels (p < 0.003). Female sex was a less significant risk factor for increased tHcy levels (p = 0.039). Our study confirms the association between hyperhomocysteinemia and epilepsy. The elevation of tHcy is essentially related to low folate levels. Correction of poor folate status, through supplementation, remains the most effective approach to normalize tHcy levels in patients on AED mono- or polytherapy

Valproic acid and phenobarbital blood levels during the first month of treatment with the ketogenic diet.

Objective – The aim of this study was to assess how the ketogenic diet influences the blood levels of antiepileptic drugs in the first month of treatment in a pediatric population with drug-resistant epilepsy. Methods – The plasma concentrations of antiepileptic drugs were investigated in an open study on 36 consecutive children and adolescents (20 males), aged between 6 months and 16 years (mean age 4.7 years), who were put on the ketogenic diet because of medically refractory epilepsy. The plasma levels of antiepileptic drugs were determined 30 days and immediately before the diet and on days 8, 15, 22 and 29 after the start of the diet. The daily dose of each drug was not changed during the first month of treatment, while the daily dose of benzodiazepines was reduced by up to 30% if excessive sedation or drowsiness occurred. Results – While plasma concentrations of phenobarbital did not change in the first month on the ketogenic diet (mean increase of 2.3 mg ⁄ l 1.0), valproic acid showed a slight but not significant decrease (mean decresase of 6.7 mg ⁄ l 3.2), 2 weeks after the start of the diet. Conclusions – Adjustments in the daily dose of either drug before the start of the diet do not however appear to be justified

Ketogenic diet prevents neuronal firing increase within the substantia nigra during pentylenetetrazole-induced seizure in rats

The mechanism responsible for the anti-seizure effect of ketogenic diets is poorly understood. Because the substantia nigra pars reticulata (SNr) is a "gate" center for seizures, the aim of the present experiment was to evaluate if a ketogenic diet modifies the neuronal response of this nucleus when a seizure-inducing drug is administered in rats. Two groups of rats were given a standard diet (group 1) or a ketogenic diet (group 2) for four weeks, then the threshold for seizure induction and the firing rate of putative GABAergic neurons within the SNr were evaluated with progressive infusion of pentylenetetrazole under general anesthesia. The results demonstrated that the ketogenic diet abolished the correlation between the firing rate response of SNr-neurons and the seizure-threshold. This result suggests that the anti-seizure effect of ketogenic diets can be due to a decrease in reactivity of GABAergic SNr-neurons