The ketogenic diet can be used successfully in combination with corticosteroids for epileptic encephalopathies.

Abstract Hormonal therapy or ketogenic diet often permits overcoming the challenging periods of many epileptic encephalopathies (West and Lennox–Gastaut syndromes and encephalopathy with continuous spike–waves in slow sleep), but relapse affects over 20% of patients. We report here a monocenter pilot series of 42 consecutive patients in whom we combined oral steroids with the ketogenic diet for corticosteroid-resistant or -dependent epileptic encephalopathy. We retrospectively evaluated the effect on seizure frequency, interictal spike activity, neuropsychological course, and steroid treatment course. Twenty-three patients had West syndrome (WS), 13 had encephalopathy with continuous spike–waves in slow sleep (CSWS), and six others had miscellaneous epileptic encephalopathies. All patients succeeded to reach 0.8 to 1.6 g/l ketone bodies in the urine following the usual KD regimen. For at least 6 months, 14/42 responded to the addition of the ketogenic diet: 4/23 with WS, 8/13 with CSWS, and 2/6 with miscellaneous epileptic encephalopathies. The addition of the KD allowed withdrawing steroids in all responders. Among them, 10/15 had been patients with steroid-dependent epileptic encephalopathy and 4/27 patients with steroid-resistant epileptic encephalopathy. Therefore, the ketogenic diet can be used successfully in combination with corticosteroids for epileptic encephalopathies. Patients presenting with steroid-dependent CSWS seem to be the best candidates.