There are few things more dramatic and frightening to watch than an epileptic seizure. Imagine you are at home with your young child when suddenly he begins to twitch or move uncontrollably, drool, cry out, or even lose consciousness. Now, imagine it happening two or three times a day, every day. For the parents of children with intractable epilepsy, this is a constant reality. Even with medications, the seizures may continue. For some of these children, the ketogenic diet may be effective in helping to control their seizures.
Epilepsy
is a condition of spontaneously recurring seizures (a sudden change in movement, behavior, sensation, or consciousness produced by an abnormal electrical discharge in the brain). It is a condition shared by approximately two million people in the US.
For almost half of those who have epilepsy, the cause of their condition is unknown. The other 50% show evidence of some sort of injury to the brain, either as a result of severe trauma,
stroke, tumor, lack of oxygen, or some other cause. Epileptic seizures occur when large numbers of brain cells all send electrochemical messages (“fire”) at the same time. This sudden burst of electrical activity in the brain disrupts normal behaviors and causes abnormal movements, confusion, and other signs and symptoms of seizures.
Approximately 80% of people with epilepsy manage to control their seizures using one or more of a number of antiepileptic drugs. However, as many as 20% will continue to have seizures despite the best possible medical treatment. While new drugs with better and different anti-epilepsy capabilities are released frequently, for those who remain resistant to drug treatment, the ketogenic diet may offer the hope of improvement. At present, the ketogenic diet is used most commonly in infants and children, but there is increasing interest in its application to adolescents and even adults.
The ketogenic diet is a high-fat, low carbohydrate dietary approach to the management of epilepsy that can dramatically reduce or even end seizures in some children with severe epilepsy. It was first developed in the early part of the last century when it was discovered that fasting could alleviate seizures, but its popularity waned with the advent of new antiepileptic drugs.
The classical ketogenic diet is based on a 4 to 1 ratio of fat to carbohydrate in the diet. There is also a modified form of the diet that uses medium chain triglycerides (MCTs) as the primary fat source in the diet.
The diet works by mimicking some of the effects of fasting on the body. When you fast, the body first burns its stored supplies of glucose (which we get from the carbohydrates we eat) for the energy it needs to maintain normal body functions. When these energy stores become depleted, the body begins to break down stored body fat for energy. This process produces ketones, substances derived from fat that can be used for energy by many of our vital organs. Along with providing energy to our muscles and brain, for reasons not yet entirely understood, ketones help alleviate seizures in certain children.
Research has shown that in some cases, the ketogenic diet can be used—either in conjunction with or as an alternative to antiepileptic drugs—to dramatically reduce or end seizures in children who have certain types of epilepsy. And while only some children who try the diet may become seizure free, others show significant improvement in their levels of alertness, awareness, and responsiveness.
The diet should be thought of as a form of medical treatment, and therefore adhered to as closely as possible. Some people consider it difficult because it requires strict adherence to an unusual and limited range of foods. Therefore, the diet must be instituted under the careful guidance of your child’s doctor and, usually, an experienced dietician. However, with the right level of guidance and support, many families say the diet can quickly become routine.
If your child is a candidate for the diet, you will be expected to keep a diary. This diary will record the number and type of seizures your child experiences each day as well as their mood, alertness, and overall behavior. Your child will also have regularly scheduled visits with his or her doctor who will monitor your child’s growth, overall health, and frequency of seizures. The diary can greatly help your doctor make decisions about changing the diet or medications your child may still be taking. You may also be asked to test your child's urine periodically to confirm that the diet is effectively leading to ketosis (buildup of ketones in the body tissues).
The exact composition of your child’s diet will depend on the type of ketogenic diet he or she is following and your child’s individual prescription. There are two main versions of the diet. The classical version focuses on the consumption of fats from foods like heavy cream. The medium chain triglyceride (MCT) version focuses on the addition of a certain type of fat (MCTs) to the diet.
A typical breakfast on the classical diet might include heavy cream, eggs, butter, and a small serving of fruit or vegetables. A typical breakfast on the MCT version of the diet would be similar, but it would allow for the inclusion of a starchy carbohydrate as well, such as a small serving of bread or cereal. A special MCT supplement would also be taken with each meal, and this could be easily mixed into either the cream or food.
A typical lunch on the classical diet might include a serving of meat, fish, or cheese for protein, a small serving of either vegetables or fruit, and fat in the form of butter, heavy cream, oil, or mayonnaise. On the MCT form of the diet, the fat would be replaced with the MCT supplement.
If your child happens to be allergic to dairy products, he or she may still be a candidate for the diet. However, it may be more difficult to implement when there are food limitations.
In general, the diet has very few side effects. Nausea or
constipation
are the most common. While these symptoms may occur when a child first starts the diet, they generally improve or disappear with time. A few children may feel sleepy and irritable while adjusting to the diet, however, this, too, will generally pass in time.
Dehydration is not an uncommon occurrence and requires prompt correction in order to avoid the need for hospitalization. Diarrhea may also occur on the MCT form of the diet.
Two unusual complications are retarded growth due to nutritional deficiency and a buildup of uric acid in the blood, which can lead to
kidney stones. Rarely the diet can be associated with
inflammation of the pancreas—a complication that may be very serious, or even fatal. While these complications are rare, they highlight the importance of administering this diet under the close supervision of your child’s doctor.
The biggest unresolved concern related to treatment with the ketogenic diet is its potentially harmful effect on blood fats (cholesterol, triglycerides, and other lipoproteins). Studies show that following the diet leads to significant elevations of fatty substances in the blood, changes which
could
lead to increased risk of
heart disease
in adult life. While there is as yet no evidence that the diet is dangerous, long-term studies have not yet proven its safety. However, based on current understanding, for many patients with intractable epilepsy the benefits of good current seizure control outweigh the still-theoretical risk of harm developing later in life.
Some children will demonstrate dramatic improvement within a week of going on the diet. Still others may require as many as three months before they start to respond. If it’s been more than three months and your child is still not responding to the diet, you should speak with your child’s doctor to see if the diet should be modified or stopped.
How long your child needs to remain on the diet will depend on the extent to which he or she is benefiting from it and how easy or difficult it is for your child and your family to maintain the diet. If your child responds well to the diet and remains seizure free for two years, most doctors will suggest moving your child slowly back to a more normal diet.
