Effective and safe diet therapies for Lennox-Gastaut syndrome with mitochondrial dysfunction

Background: Lennox-Gastaut syndrome (LGS) is a typical intractable form of epilepsy that most often occurs between the second and sixth year of life. This study aimed to evaluate the clinical efficacy and safety of ketogenic diet therapies (DTs) for LGS with mitochondrial dysfunction. Methods: This was a retrospective study involving 20 LGS patients with mitochondrial dysfunction who received several DTs from 2004 to 2014 at a single tertiary care center. Seizure reduction rate, cognitive function, retention rate, electroencephalography (EEG) changes, and adverse effects were examined before and after DTs. Results: The retention rates at 1 and 2 years after initiation of DTs were 45% and 40%, respectively. After 1-year follow up, we observed seizure freedom in two patients, 75% seizure reduction in two patients, 50% reduction in three patients, and 25% reduction in one patient. After 2-year follow up, the outcomes were seizure freedom in two patients, 90% seizure reduction in one patient, 75% reduction in two patients, and 50% reduction in two patients. EEG findings improved in nine patients. Nine patients were treated with DTs for 1 year; all patients demonstrated improved cognitive status. Eight patients were treated with DTs for 2 years, of whom seven had improved cognitive status. Poor tolerability of DTs was due to poor oral intake and gastrointestinal problems. Conclusions: We demonstrate that, in LGS with mitochondrial dysfunction, improvement of seizures and cognitive function are not inferior to those in other patients treated with DTs. This study showed that DTs are efficacious and feasible for LGS patients with mitochondrial dysfunction and can significantly improve their prognosis.