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Most children with epilepsy in childhood achieve seizure freedom
with anticonvulsant medication, and many outgrow their epilepsy and
can be seizure-free and medication-free in adulthood. However, up
to one third of patients can have intractable epilepsy, usually
defined as continuing to have debilitating seizures despite the
use of 2 or 3, appropriately chosen anticonvulsant medications at
high therapeutic doses. For some children who have focal epilepsy,
surgical resection of the responsible focus offers an alternative
approach, and possibly cure of epilepsy. For others who do not have
a surgical option, dietary manipulation and new techniques of neurostimulation
offer approaches that may improve or even achieve seizure control. For
those children whose seizure control improves, a reduction in medication
dose or number can improve quality of life by reducing adverse effects.
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The Ketogenic
Diet (KD)
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The ketogenic diet simulates the biochemical changes of fasting
by providing the majority of calories in the diet from fat. The
dietary fat is metabolized via acetyl coenzyme A to ketone bodies
(acetoacetate 3-hydroxybutyrate and acetone) and fatty acids.1 In
the context of reduced glucose availability, the body utilizes ketone
bodies and free fatty acids for energy production. On a ketogenic
diet, approximately 90% of calories consumed are from fat
in contrast to a standard Western diet in which approximately 30% of calories
are from fat. A ketogenic diet is high in fat, low in carbohydrate (10
to 15 gm/day), and provides adequate protein for health and
growth (~ 1 gm/kg/day in children); typically
it involves a 3:1 to 4:1 ratio of fat (grams) to carbohydrate and
protein (grams).2In order to maintain ketosis, the components
of each meal, snack, or beverage must preserve this ratio. The carbohydrate
content of medications must be considered and minimized, usually
by eliminating sugary liquid or chewable tablets in favor of standard
tablet formulations. The diet can be provided using formula preparations for
young infants and for patients using feeding tubes. The successful
use of the ketogenic diet requires medical supervision, and the
input ofa specifically trained, knowledgeable nutritionist for
diet design, adjustment, and surveillance of growth and nutritional
status. Parent education for the practicalities of weighing
and measuring food components, managing food preferences and feeding
behaviors, and adjusting for intercurrent illnesses, holidays, and
variable energy demands, is essential . An
intangible additional component of successful ketogenic diet programs
is the ability to enthusiastically support families over the long
term, who are engaged in a difficult, life-altering, but potentially
rewarding process.
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The ketogenic diet fell out of favor in most centers with the
discovery of phenytoin and remained unpopular as newer drugs came
to market. However, it has become clear that though safer than the
older anticonvulsant drugs, the new drugs are not necessarily more
effective. This has led to a resurgence of interest in diet treatment.
In patients with epilepsy who fail to be controlled with a first
anticonvulsant, the use of an alternative ...