Randomised Trial Confirms Efficacy Of Ketogenic Diet In Preventing Epileptic Seizures In Children

Main Category: Epilepsy
Also Included In: Pediatrics / Children's Health
Article Date: 03 May 2008 - 1:00 PST

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A randomised controlled trial has confirmed the efficacy of the ketogenic diet in helping control and prevent epileptic seizures in children with drug-resistant epilepsy. These are the conclusions of authors of an Article published early Online and in the June edition of The Lancet Neurology.

The ketogenic diet has been used widely and successfully to treat children with drug-resistant epilepsy since the 1920s. It is a diet very high in fat, low in carbohydrate, and with controlled protein. Although the exact mechanism of action is still unclear, the high fat and restricted carbohydrate content of the diet is thought to mimic the biochemical response to starvation, when ketone bodies*, rather than sugars, become the main fuel for the brain's energy demands. While there have been many observational studies of this diet, Professor J Helen Cross, Institute of Child Health and Great Ormond Street Hospital for Children NHS Trust, University College London, UK, and colleagues have done the first randomised controlled trial to test its efficacy.

The trial assessed 145 children aged between 2 and 16 years who had at least daily seizures (or more than seven seizures per week), had failed to respond to at least to antiepileptic drugs, and had not been treated previously with the ketogenic diet. Enrolment for the study took place between 2001 and 2006, and children were seen at one of two hospital centres or a residential centre for young people with epilepsy. All children had their baseline seizure levels recorded over a four week period. Following this, 73 were assigned to the ketogenic diet immediately, and 72 were assigned to the diet after a delay of three months - both groups had no other changes to treatment. The delay group acted as the control group during the three month delay.

The researchers obtained complete data for 54 children in the diet group and 49 in the control group. Using the baseline figures as 100%, they found that the number of seizures in the diet group dropped by more than a third (62% of seizures recorded compared with baseline), while the control group saw their seizures rise by more than a third (136•9% of seizures compared with baseline). 28 of the 54 children who completed the three months in the diet group had greater than 50% seizure reduction compared with just four of 49 children in the control group. Five children in the diet group saw a seizure reduction of above 90%, compared to none in the control group. The most frequent side-effects reported at three months were constipation, vomiting, lack of energy, and hunger.

The authors say: "We have shown that the diet has efficacy and should be included in the management of children who have drug-resistant epilepsy. However, the diet is not without possible side-effects, which should be considered alongside the risk benefit of other treatments when planning the management of such children."

They add: "In view of this we believe that the diet should be more widely available as a treatment on the NHS, for children with epilepsy, who have failed to respond to anticonvulsant medication. We stress this is a diet which should only be undertaken on medical advice and under medical and dietetic supervision."†

In an accompanying Reflection and Reaction comment, Dr Max Wiznitzer, Rainbow Babies and Children's Hospital, Cleveland, OH, USA, says that more information is needed about the long-term effects of the ketogenic diet, including changes in blood fat concentrations and persistent ketosis. He adds: "Better identification of epilepsies that benefit from starting early on the ketogenic diet and comparisons between the choices of ketogenic diet are needed."

*Ketone bodies are water soluble compounds that are produced as by products when fatty acids are broken down for energy in the liver and kidneys. They are used as a source of energy in the heart and brain. In the brain, they are a vital source of energy during fasting.

†This second quote from the authors is their opinion and cannot be found within the Article.

"The ketogenic diet for the treatment of childhood epilepsy: a randomised controlled trial"
Elizabeth G Neal, Hannah Chaffe, Ruby H Schwartz, Margaret S Lawson, Nicole Edwards, Geogianna Fitzsimmons, Andrea Whitney, J Helen Cross
Lancet Neurology - May 3, 2008DOI:10.1016/S1474-4422(08)70092-9

The Lancet Neurology