Long-term outcomes of ketogenic diet in patients with tuberous sclerosis complex-derived epilepsy

Objective: For epilepsy with tuberous sclerosis complex (TSC), ketogenic diet (KD) therapy has been consistently reported to be more beneficial than the average KD therapy response. Herein, we aimed to investigate the long-term outcomes of a KD on patients with TSC and intractable epilepsy. Methods: This study included 31 patients with intractable epilepsy and TSC who were treated with the KD, and an intention-to-treat analysis was performed. Results: Overall, 21 of the 31 patients (67.7%) had >50% reduction in seizures at 3 months after initiating the KD. Thirteen of the 31 patients (41.9%) were seizure-free for at least 3 months, but 10 of these 13 patients (76.9%) experienced seizure recurrence during the 24-month follow-up period. Finally, at 24 months of the KD observational period, there was >50% response in 10 of the 31 patients (32.3%), including seizure-free patients (6 of 31 patients, 19.4%). Most of the patients (12 of 13, 92.3%) who experienced seizure freedom had >50% reduction in seizures within 1 month after initiating the KD, and this result was the only factor associated with seizure freedom in the current study. Conclusion: The KD appeared to be an effective therapeutic modality for intractable pediatric epilepsy in TSC, but it did not exhibit guaranteed efficacy over a long-term period.