The Early Response to Dietary Therapy can Predict the Late Outcome in Children with Intractable Epilepsy

Dietary therapy (DT), including the ketogenic diet (KD), is one of the nonpharmacological treatment options for patient with drug-resistant epilepsy. However, maintaining DT in patients without seizure reduction is very difficult, so it is critical for clinicians to decide when to stop this intervention. We retrospectively analyzed early clinical and laboratory findings and the clinical characteristics of children who received DT. The maintenance of DT and the clinical seizure frequency were assessed at 1, 3, 6, 12, and 24 months after KD initiation. Responders were defined as patients showing an overall reduction in seizure frequency of >50% relative to the baseline. We included 67 patients who received DT, but only 23 (34.3%) of these patients remained on DT at 6 months. Only 1 (5%) of the 20 responders at 1 month became a nonresponder at 6 months. The response rate at 6 months was significantly higher among patients under 2 years of age (15/17, 88.2%) than older patients (2/6, 33.3%; =0.021). Moreover, the 6-month responders were significantly younger (29.4±38.6 months, mean±SD) than the nonresponders (98.9±84.6 months, =0.012) at the initiation of the diet. A high blood β-hydroxybutyrate (BHB) level at 1 month predicted a good DT response at 6 months. Most 1-month responders maintained their response on DT for up to 6 months. The blood BHB level at 1 month was significantly correlated with the 6-month seizure outcome. Confirming clinical and laboratory biomarkers for the efficacy of DT requires further studies with larger cohorts.