Carnitine deficiency in children with pharmacoresistant epilepsy during treatment with ketogenic diet

Introduction: Carnitine is essential for oxidation of fatty acids and ketogenesis. Carnitine deficiency has been reported for ketogenic diet (KD). We investigated the changes in carnitine metabolism in our own patients during KD.

Methods: In 19 children with pharmacoresistant epilepsies, carnitine and acyl carnitines were measured by tandem mass spectroscopy during KD. Time of follow-up was median (range) 36 (1–248) weeks. At the beginning of the KD, 14 children were without carnitin supplementation. Their time of follow-up was median (range) 32 (0,5–248) weeks.

Results: In 57% (8/14) of the children without initial carnitin supplementation, carnitine was decreased 3 days to 248 weeks after beginning of KD. At the latest check-up on KD, 58% (11/19) had carnitine substitution, 26% (5/19) presented with carnitine deficiency, 2 of them despite carnitine substitution.

No child developped symptomatic carnitine deficiency. There was no significant association between decreased carnitine and valproate therapy.

Conclusion: During treatment with KD regular controls of the carnitine level are necessary, both at the beginning and during long term therapy.

Keywords: ketogenic diet, carnitine, epilepsy