Risk of seizure recurrence after achieving initial seizure freedom on the ketogenic diet

Summary Objective Few studies have examined the long‐term sustainability of complete seizure freedom on the ketogenic diet ( KD ). The purpose of this study was to describe the risk of seizure recurrence in children who achieved at least 1 month of seizure freedom on the KD , and to assess clinical features associated with sustained seizure freedom. Methods Records of patients initiated on the KD at The C hildren's H ospital of P hiladelphia ( CHOP ) from 1991 to 2009 were reviewed. Subjects who attained seizure freedom for at least 1 month within 2 years were included in the study. Seizure frequency was recorded based on caregiver‐reported seizure diaries as unchanged, improved, or worse compared to baseline. Those patients with seizure freedom ≥1 year were compared to those with seizure freedom <1 year in terms of demographics, age of seizure onset, number of antiepileptic drugs ( AED s) prior to KD , and epilepsy classification. Results Of 276 patients initiated on the KD , 65 patients (24%) attained seizure freedom for a minimum of 1 month. The majority of these patients had daily seizures. The median time to seizure freedom after KD initiation was 1.5 months. Seizures recurred in 53 patients (82%), with a median time to seizure recurrence of 3 months. However, seizure frequency after initial recurrence remained far less than baseline. No clinical features were identified as risk factors for seizure recurrence. Significance Seizure recurrence on the KD after 1 month of seizure freedom most often occurred as occasional breakthrough seizures and not a return to baseline seizure frequency. This study provides evidence to support the continued use of the KD in patients with initial seizure freedom even after breakthrough seizures. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here .