Seizures / Epilepsy (Questions 16-18)
16. The Ketogenic Diet
This is a difficult diet to maintain, but it does prevent seizures, especially in younger children (1-8 years). Seizures that fail to be controlled with anti-convulsant medications may respond well to this diet.
The diet’s mechanism is based on the principle that starvation may prevent seizures. During a starvation period, fat is broken down for energy metabolism. When fat is broken, ketone bodies are formed. These are acetone, acetoacetic acid, and beta-aminobutric acid. The ketone bodies have anti-seizure properties. By applying the Ketogenic diet, one stimulates a starvation situation without actively starving. This is accomplished by feeding an individual only fat. When fat is consumed it is broken into the ketone bodies as if these are the actual fat stores of the body. During the period of treatment (usually 2 years), a child cannot have any carbohydrate intake (bread, pasta, sugar, or flour products). Proteins are limited to a small amount and the entire diet is strictly calculated to the gram. Also the fluid intake is limited in order to maintain a proper concentration of ketones.
The general notion is that the diet stops seizures in 30%, reduces them in 30%, and is ineffective in about 30%. The best candidates are children who have frequent small generalized or focal seizures who didn’t respond to any anticonvulsant or can’t tolerate them due to side effects and are between 1 and 8 years of age. Some severe seizure forms such as Lenox-Gastaut syndrome or infantile spasms may respond well to the diet.
The diet is not free of side effects, other than the inconvenience of maintaining it. The diet may cause growth retardation, kidney stones, side effects related to exposure to fat, and more. Proper vitamin supplementation, calcium, and mineral supplementation must be maintained while on the diet. Still, with all its difficulties, for the right candidate with a motivated capable family, this is an excellent option to be considered.
17. Vagus Nerve Stimulation
In vagus nerve stimulation, a coil is wrapped around the vagus nerve and is stimulated electrically with a pacemaker-like device that is placed under the skin, below the clavicle. The repetitive stimulation of the vagus nerve delivers an impulse to the brain that is protective against seizures. The implementation of the device requires a minor surgical procedure.
The device becomes activated about 2 weeks following the implementation and the neurologist controls the amount of stimulation delivered. Other than seizure protection, vagus nerve stimulation is reported to improve memory, decrease side effects, as these are being weaned off. Recently, some reports indicate beneficial effects in mood disorders.
18. Epilepsy Surgery
Most commonly consists of resectioning an epileptogenic (seizure producing) brain region. Surgery is usually the last resort for patients who fail to respond to other anti-epileptic managements. There are several surgical options depending on the type and location of the seizure focus.
The most successful epilepsy surgery is for the treatment of partial seizures when a clear lesion can be detected, such as in the case of mesial temporal sclerosis, or the atrophy of the gray matter in a very specific area at the tip of the temporal lobe. When the lesion is on the right side, chances are better that language will not be affected by surgery. Prior to the surgery, however, close EEG monitoring is required in order to localize the seizure focus precisely and to prevent the extraction of functional brain regions. In some situations an EEG grid is implanted close to the brain in order to obtain more accurate monitoring.
The results of surgery are generally good, making it a valid option for the appropriate candidate. Families, however, should be aware of some potential surgical complications, the possibility (depending on the seizure type) that seizures will continue after the surgery, and that medication may be needed in combination with surgery to obtain the best seizure control.