Long-term effectiveness and adverse effects of ketogenic diet therapy in infants with drug-resistant epilepsy treated at a single center in Argentina

Introduction: Ketogenic diet therapy (KDT) is a metabolic treatment with proven effectiveness for the treatment of drug-resistant epilepsy in children. Although previously not used in infants under 2 years of age, recent studies have shown KDT to be highly effective and well tolerated in infants with epilepsy, especially those with epileptic encephalopathies. Here, we describe the effectiveness and tolerability of the diet in infants up to 2 years of age. Material and methods: A prospective study was conducted in a cohort of infants younger than 2 years of age with drug-resistant epilepsy who received the classic ketogenic diet using a specific protocol at a single center in Argentina. Results: 56 infants with treatment-refractory epilepsy were evaluated. The etiology was genetic in 21.4%, structural in 28.6%, unknown in 44.7%, and metabolic in 5.4%. At 3 months, a > 50% decrease in seizure frequency was observed in 35 patients (62.4%), of whom 11 (19.6%) became seizure free. At 6 months, 34 patients (60.7%) had a decrease in seizure frequency of > 50%, of whom 10 (17.8%) were seizure free. At the one-year follow-up, 27 patients (48.2%) had a > 50% decrease in seizure frequency, of whom six (10.7%) were seizure free. At two years, 14 patients (25%) had a > 50% seizure control, of whom four (7.1%) were seizure free. The most common early adverse effects were hypoglycemia and vomiting, while after 1 month and beyond metabolic acidosis, vomiting, and constipation more commonly found. A trend towards a higher rate of acute adverse events in infants younger than 1 year was observed. Conclusions: CKD showed to be a useful option in infants with treatment-resistant epilepsy. Adverse effects were common, but not a reason to discontinue the diet. Further studies are necessary to evaluate in which epilepsy syndromes and etiologies KDT is most effective.