Ketogenic diet in children with difficult to treat epilepsies – 6 years of clinical experience

Ketogenic diet (KD) is an established treatment for epilepsies since 90 years.

Several studies about effectiveness of ketogenic diet in children proofed responder rates up to 50%.

Methods: Between November 2003 and December 2009 we initiated KD in 41 in-patients (15 female, 26 male). The effectiveness of KD was evaluated after a 3-months follow-up. In patients with ≥50% seizure reduction we classified KD as effective.

Our patients had an age of 8 (median) years (range 11 months to 15.7 years).

19 were suffering from a symptomatic focal epilepsy, 7 from a cryptogenic focal epilepsy, 5 from an idiopathic generalised epilepsy, 5 from an epilepsy with focal and generalised signs, 2 from a progressive myoclonic epilepsy. 1 patient had CSWS, 1 a Lennox-Gastaut Syndrome and 1 a Dravet Syndrome.

Duration of epilepsy was 5.3 (median) years (range 4 months to 11 years).

In the past treatments with 8 (median) different anticonvulsive drugs (range 1 to 15) had failed.

The followed was 19.5 (median) months (maximum 40 months) in those patients who responded to KD.

Results: 12 patients on KD had a 50% to ≥90% reduction of seizure frequency.

Even after discontinuation of KD after 15–40 months 5 of these patients kept stable concerning seizure frequency. 7 patients are still on KD for more than 3–38 months with a persisting efficacy. In 67% of the responders we saw tolerable or treatable unwanted side effects, for example abdominal cramps, constipation or decreased Vitamin D levels.

6 of all patients (3 responders, 6 non-responders) had an improvement of attention and activity. In 16 patients we stopped KD because of a poor reduction of seizure frequency. 13 patients stopped KD because of other reasons, e.g. disgust for fatty meals.

Discussion: We couldn't see a clear influence of patients age, duration of epilepsy or the type of epilepsy on the efficacy of KD.

Looking at our responder rate we must take into account that in most of our patients KD was used as „last treatment option“ after failure of established anticonvulsant drugs.

To optimise the installation of KD and to reduce unwanted side effects a multidisciplinary team approach is needed as well as a tight cooperation with the patients' parents.

Keywords: ketogenic diet, difficult to treat epilepsy