P&S Journal: Spring 1997, Vol.17, No.2
Dietary Controls for Seizures
Neurologists and nutritionists are using a high-fat, low-carbohydrate diet to control seizures in epileptic children who do not respond to or cannot tolerate medication. The "ketogenic diet" was devised in the 1920s, following anecdotal reports that fasting cured epilepsy. The first to confirm scientifically that fasting could moderate seizures was Columbia's H.R. Geyelin. Around the same time, a doctor at the Mayo Clinic proposed a high-fat diet as a way to simulate the effect of starvation. Although the diet was found to be useful, it fell out of favor over the years with the advent of effective anti-seizure medications, says Dr. Douglas Nordli Jr., an Irving Assistant Professor in Neurology and an assistant professor of pediatrics.
The diet, however, is making a comeback as a therapy for children with epilepsy who either do not respond to medical treatment or suffer intolerable side effects. It is estimated that approximately 15 percent of the nation's 375,000 young epileptics fall into this category.
To begin the ketogenic diet, the patient must fast for about a day and a half; only water and sugar-free beverages are allowed. The diet begins after the child becomes "ketotic," as indicated by the presence of ketones in the urine. Because each meal is high in fat and low in protein and carbohydrates, the body continues to burn fat for energy, sustaining the ketotic state. The fast, as well as the first three days of the dietary intervention, must be conducted in the hospital.
Studies show that the ketogenic diet completely controls seizures in about a third of the children and lessens seizures in another third. Some children can be taken off medications completely. Younger children (ages 1 through 8) tend to gain the most from the diet. It is rarely helpful for adults.
Children who respond to the diet are kept on the regimen for an unlimited period of time, with monthly follow-up visits to the doctor or nutritionist. Doctors do not understand how the diet works, but animal research conducted at P&S by Dr. Darryl De Vivo, the Sidney Carter Professor of Neurology and a professor of pediatrics, suggests that high-fat diets increase the ratio of adenosine triphosphate (ATP) to adenosine diphosphate (ADP), molecules involved in energy production. A higher ATP to ADP ratio somehow enhances the stability of neurons in the brain.
The biggest problem with the diet is compliance. One slip can cause a major setback. "The most common problem resulting in lowered ketosis is ingestion of additional 'forbidden' foods," says Dr. Nordli. Even small amounts of additional sugar--one cookie, for example--can throw the diet off and result in worsening seizures. Sugar in medications, mouthwashes, or toothpastes also may confound the diet. Younger children, who are less likely to have developed strong eating habits, tend to have an easier time with compliance.