The ketogenic diet (KD) is a high-fat, low-carbohydrate diet with an established efficacy for treating medically refractory epilepsy in children. Fatty acids are the most important constituent of the KD in all aspects of efficacy and complications. Among fatty acids, polyunsaturated fatty acids (PUFAs) increase anticonvulsant properties and reduce the complications associated with the high-fat diet.

Here, we report a 7-year-old boy with Lennox-Gastaut syndrome combined with mitochondrial respiratory chain complex I deficiency, whose medically intractable seizures have been successfully controlled with a PUFA-enriched modified Atkins diet without any significant adverse events.

The diet consists of canola oil and diverse menu items like fish and nuts instead of olive oil and has an ideal 1:2.8 ratio of omega-3 to omega-6. In addition, fractionation of this boy's plasma showed normal levels of fatty acids, including omega-3 (alpha-linoleic acid, eicosapentaenoic acid) and omega-6 (linoleic acid, arachidonic acid) as well as monounsaturated fatty acids (oleic acid).

Plasma docosahexanoic acid remained low after PUFA-enriched diet therapy. PUFA-enriched diet therapy is likely to increase the efficacy of diet therapy and reduce complications of a high-fat diet in children with refractory epilepsy.