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Although highly effective for the treatment of intractable epilepsy, the ketogenic diet is not always included in the treatment option hierarchy presented to families, in part due to perceptions that children will find the high-fat/low-carbohydrate regimen unpalatable. This study assessed if children with seizures exhibit food preferences compatible with the diet, as well as if caregivers were accurate in predicting preferences. Children aged 2-17, with (n=29) and without (n=30) a history of seizures, participated in a paired choice food preference assessment while parents estimated child preferences verbally. Children with seizures exhibited significantly higher preferences for fat versus carbohydrate foods compared with controls, and parents demonstrated low accuracy. Future studies could use similar assessment methods to prospectively track whether such preferences predict diet compliance and/or efficacy. Research into the underlying metabolic basis for this preference and possible related neurophysiological mechanisms in seizure etiology and treatment is warranted.

A cohort study was performed of children started on the ketogenic diet for intractable epilepsy from 2000 to 2005 (n = 195). Children who developed kidney stones were compared with those without in terms of demographics, urine laboratory markers, and intervention with urine alkalinization (potassium citrate). Thirteen children (6.7%) developed kidney stones. The use of oral potassium citrate significantly decreased the prevalence of stones (3.2% vs 10.0%, P = .049) and increased the mean time on the ketogenic diet before a stone was first noted (260 vs 149 patient-months, P = .29). The prevalence of kidney stones did not correlate with younger age or use of carbonic anhydrate inhibitors (eg, topiramate or zonisamide) but trended toward higher correlation with the presence of hypercalciuria (92% vs 71%, P = .08). No child stopped the diet due to stones; in fact, the total diet duration was longer (median 26 vs 12 months, P < .001). Kidney stones continue to occur in approximately 1 in 20 children on the ketogenic diet, and no statistically significant risk factors were identified in this cohort. As oral potassium citrate was preventative, prospective studies using this medication empirically are warranted.

The ketogenic diet remains a valuable therapeutic option for patients with intractable epilepsy. Clinical aspects of the diet's success may provide insights into epileptogenesis and anticonvulsant action. The diet's efficacy has been established primarily through large case series. The diet has been used successfully in patients with many different epilepsy syndromes in countries around the world. Potential adverse effects can be avoided with careful attention during the diet's initiation and maintenance phases. In the last decade, variations to the classical ketogenic diet have been utilized. Ketogenic diets now are being used for diseases other than epilepsy. This critical analysis of the diet should provide the impetus for further clinical and basic research into the diet's application and mechanisms of action.

Although the success rates and complications of various treatment options for children with intractable epilepsy have been described, the actual expectations of parents for these treatments are less clear. Since 1998, parents at our institution have written their goals in a letter before starting their children on the ketogenic diet. One hundred consecutive letters were evaluated. The most common first goal was seizure improvement, second was anticonvulsant reduction, and third was cognitive improvement. Ninety percent requested improvement in cognition or alertness. These expectations were either met or exceeded at 6 months in 52-60% of children. Achieving or surpassing parental expectations for cognitive improvement correlated with longer diet duration (P=0.04), but meeting goals for seizure or anticonvulsant reduction did not. Cognitive improvement (P<0.001) and >90% seizure reduction (P=0.04) at 6 months positively correlated with longer eventual diet duration. Expectations for cognitive improvement need to be discussed prior to beginning the ketogenic diet.

The ketogenic diet has traditionally been considered an anticonvulsant therapy of last resort, despite excellent efficacy and limited side effects. We hypothesized that the ketogenic diet would have similar results in patients with new-onset epilepsy. A retrospective study was conducted of patients started on the ketogenic diet since 1994. Thirteen of 460 (2.8%) patients were started on the ketogenic diet as early (zero or one prior anticonvulsant) therapy for seizures. Of those remaining on the diet, 60% (6 of 10) had a > 90% seizure reduction at 6 months and 100% (6 of 6) had a > 90% reduction at 12 months. Patients with infantile spasms were as likely to achieve > 50% seizure reduction at 6 months as patients with other seizure types (75% vs 60%; P = .6). The ketogenic diet can be a valuable therapy before epilepsy becomes intractable. In the 13 patients reported, efficacy without side effects was achieved similarly to that with patients with intractable epilepsy.

The ketogenic diet is an effective alternative therapy used to control intractable seizures. It was originally described in 1921 as a way to duplicate and prolong the beneficial effects that fasting appeared to have on seizure control. It involves consuming a calorie-restricted diet in which the fat:carbohydrate + protein ratio ranges from 2:1 to 5:1. Recent prospective studies in children demonstrate that about 50% of children will continue on the diet for at least a year, with 40-50% of those starting the diet having a >50% reduction in seizures after 12 months. When the diet is discontinued it is usually due to lack of efficacy. The diet is a radical medical therapy and nutritional well-being is a constant concern. Renal stones have occurred in 5-8% of children on the diet; lipids are elevated, but the significance of this is not known. The mechanism of action of the diet remains unknown, and it is difficult to assess which biochemical parameters should be monitored as adjustments are made to the diet.

The Ketogenic Diet is an effective treatment for epilepsy in children. At Johns Hopkins Hospital more than 400 children have been placed on the Ketogenic Diet. The implementation and maintenance of this treatment require significant collaboration between the family and Epilepsy Team. During initiation of the diet, in the hospital, parents attend classes on the history and mechanism of the diet, preparation of meals, psychological issues, complications and the management of childhood illnesses on the ketogenic diet. Many factors are considered in calculating a ketogenic formula. Age, weight, height and activity level are the obvious factors. However, secondary medical diagnoses, medications, neurological deficits, feeding issues and psychological issues are additional factors that affect the formulation of an optimal ketogenic prescription. Once this prescription has been formulated and implemented, many patients require fine-tuning of their ketogenic diets to get the best antiepileptic results while promoting growth. We believe that our success in sustaining this treatment is related to our fine-tuning and management practices.

In a prospective study of the efficacy of the ketogenic diet in children with severe, refractory epilepsy, data were collected on medication changes over 1 year. Cost reductions in medications were calculated over the first year and estimated for a second year. Fifty-seven percent of the children stayed on the diet for 1 year, and 74% of these children had their number of medications reduced. Forty-eight percent of children who stayed on the diet were on no medications at 12 months follow-up. Daily medication costs were reduced by nearly 70%.

Objective: The ketogenic diet is a high-fat, low-protein, low-carbohydrate diet developed in the 1920s for the treatment of children with difficult to control seizures. Despite advances in both the pharmacotherapy and the surgery of epilepsy, many children continue to have difficult-to-control seizures. This prospective study sought to determine the ketogenic diet's effectiveness and tolerability in children refractory to today's medications., Methods: One hundred fifty consecutive children, ages 1 to 16 years, virtually all of whom continued to have more than two seizures per week despite adequate therapy with at least two anticonvulsant medications, were prospectively enrolled in this study, treated with the ketogenic diet, and followed for a minimum of 1 year. Seizure frequency was tabulated from patients' daily seizure calendars and seizure reduction calculated as percentage of baseline frequency. Adverse events and reasons for diet discontinuation were recorded., Results: The children (mean age, 5.3 years), averaged 410 seizures per month before the diet, despite an exposure to a mean of 6.2 antiepileptic medications. Three months after diet initiation, 83% of those starting remained on the diet and 34% had >90% decrease in seizures. At 6 months, 71% still remained on the diet and 32% had a >90% decrease in seizures. At 1 year, 55% remained on the diet and 27% had a >90% decrease in seizure frequency. Most of those discontinuing the diet did so because it was either insufficiently effective or too restrictive. Seven percent stopped because of intercurrent illness., Conclusions: The ketogenic diet should be considered as alternative therapy for children with difficult-to-control seizures. It is more effective than many of the new anticonvulsant medications and is well tolerated by children and families when it is effective.

Objective: To determine the efficacy of the ketogenic diet in multiple centers., Design: A prospective study of the change in frequency of seizures in 51 children with intractable seizures who were treated with the ketogenic diet., Setting: Patients were enrolled from the clinical practices of 7 sites. The diet was initiated in-hospital and the patients were followed up for at least 6 months., Patients: Fifty-one children, aged 1 to 8 years, with more than 10 seizures per week, whose electroencephalogram showed generalized epileptiform abnormalities or multifocal spikes, and who had failed results when taking at least 2 appropriate anti-epileptic drugs., Intervention: The children were hospitalized, fasted, and a 4:1 ketogenic diet was initiated and maintained., Main Outcome Measures: Frequency of seizures was documented from parental calendars and efficacy was compared with prediet baseline after 3, 6, and 12 months. The children were categorized as free of seizures, greater than 90% reduction, 50% to 90% reduction, or lower than 50% reduction in frequency of seizures., Results: Eighty-eight percent of all children initiating the diet remained on it at 3 months, 69% remained on it at 6 months, and 47% remained on it at 1 year. Three months after initiating the diet, frequency of seizures was decreased to greater than 50% in 54%. At 6 months, 28 (55%) of the 51 initiating the diet had at least a 50% decrease from baseline, and at 1 year, 40% of those starting the diet had a greater than 50% decrease in seizures. Five patients (10%) were free of seizures at 1 year. Age, sex, principal seizure type, and electroencephalogram were not statistically related to outcome., Conclusion: The ketogenic diet is effective in substantially decreasing difficult-to-control seizures and can successfully be administered in a wide variety of settings.

The ketogenic diet was developed in the 1920s as a treatment for intractable childhood seizures when few antiepileptic drugs (AEDs) were available. There are still children whose seizures are refractory even to modern therapy, but use of the ketogenic diet appears to be waning. At Johns Hopkins, we continue to believe that the diet is very effective and well accepted by patients and families. To reevaluate our opinion of the efficacy and acceptability of this form of therapy in patients cared for in the 1980s with the newer AEDs, we analyzed the records of 58 consecutive patients who had been started on the diet. Before using the diet, 80% of the patients had multiple seizure types and 88% were treated with multiple AEDs; these children were among our most intractable patients. Despite this, seizure control improved in 67% of patients with the ketogenic diet, and actuarial analysis indicated that 75% of these improved patients continued the diet for at least 18 months. Sixty-four percent had AEDs reduced, 36% became more alert, and 23% had improved behavior. The improvement in these patients with intractable seizures and the length of time that families maintained the regimen indicate that the ketogenic diet continues to have a very useful therapeutic role in selected patients and their families.