The Ketogenic Diet for Adults With Epilepsy

Andrew N. Wilner, MD


August 15, 2014

Ketogenic Diet Treatment in Epilepsy

Epilepsy affects 65 million people worldwide. Although antiepileptic drugs (AEDs) can control seizures in 60%-70% of people with epilepsy, the remaining 30%-40% with refractory epilepsy must resort to other treatments.[1] These patients have many high-tech options, such as the vagus nerve stimulator (VNS), deep brain stimulation (DBS), responsive neurostimulation (RNS), and epilepsy surgery. Another option is ketogenic diet treatment, usually reserved for children with developmental disabilities and refractory epilepsy.

What Is the Ketogenic Diet?

The ketogenic diet is a high-fat, low-carbohydrate, and adequate protein diet developed 90 years ago at the Mayo Clinic. The high fat content creates ketosis, which appears to prevent seizures.

In addition to the ketogenic diet, there are several other high-fat, low-carbohydrate diets for seizure control: low-glycemic-index, medium-chain triglyceride, and modified Atkins diets. All require medical supervision and vitamin and mineral supplements.

Evaluating Dietary Therapies in Epilepsy

A recent study[2] evaluated the success of the ketogenic and modified Atkins diet in adults with epilepsy.

Study methods. Schoeler and colleagues[2] report their observations of 23 adults (13 women and 10 men aged 16-65 years; mean age at start of diet, 30.8 years) in whom a mean of 7.8 AEDs had failed and who tried a ketogenic diet. VNS therapy had failed in 5 patients (22%), and surgery had failed in 2 patients (9%).

The patients had a wide range of epilepsy syndromes, including 13 with no diagnosed syndrome, 7 with epilepsy associated with structural or metabolic conditions, 2 with juvenile myoclonic epilepsy, and 1 with ring chromosome 17. The period of evaluation was 1-10 years. Five (22%) of the patients followed the classic ketogenic diet and the rest (78%) the modified Atkins diet, which often included medium-chain triglyceride supplements.

Findings. A response (≥ 50% seizure reduction) was seen in 39% of patients (9 of 23). Moreover, 65% were "more alert or brighter," 61% reported less severe or shorter seizures, 57% experienced quicker recoveries, 35% had "more energy," and 35% were able to reduce the number of their AEDs. None of the patients became seizure-free.

Adverse events. The most common adverse events were gastrointestinal symptoms, such as constipation, diarrhea, and vomiting, which affected 65% of the study group. One patient had psychosis. The diet was discontinued by 7 patients (30%), primarily for ineffectiveness. None of the patients stopped the diet as a result of adverse events.


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