[Prospective multicenter study on long-term ketogenic diet therapy for intractable childhood epilepsy].
OBJECTIVE
To evaluate the efficacy and safety of long-term ketogenic diet (KD) on the children with intractable epilepsy.


METHOD
This was a prospective, open-label study of intractable epilepsy patients treated with the classic KD with a lipid-to-nonlipid ratio 4:1 between October 2004 and July 2011 at five Chinese epilepsy centers. A total of 299 patients were enrolled. The patients were divided into different groups according to age (including the below-1-year-old group, 1-to-3-year-old group, 3-to-6-year-old group, 6-to-10-year-old group, and over-10-year-old group), etiology (cryptogenic epilepsy, symptomatic epilepsy, and idiopathic epilepsy), and the seizure types (included infantile spasm, Lennox-Gastaut syndrome, Ohtahara syndrome, tuberous sclerosis, Dravet syndrome, generalized epilepsy, and partial epilepsy). Parents were assigned to write seizure diaries which recorded the seizure presentations, tolerability, and complications associated with the KD. Patients' weight and height were measured every week. Blood β-hydroxybutyric acid, blood sugar, and urinary ketone bodies were monitored closely. Patients were followed up through telephone calls by the nutritionists every month and regular outpatient visits or hospitalizations were recommended at all time-points which included the third, sixth and twelfth month after initiation. Efficacy was measured through seizure frequency. The variables related to the efficacy were also analyzed. SPSS 17.0 was used for all statistical analysis.


RESULT
At 3, 6, and 12 months after initiation, 65.9%, 44.8%, and 26.4% patients remained on the diet, and 37.4%, 26.1%, and 20.4% had a > 50% reduction in their seizure frequency, including 21.7%, 10.7%, and 11.0% who became seizure free, respectively. At 24 months after initiation, 29 patients remained on the diet, and 28 patients had a > 90% seizure reduction, including five became seizure free. At 36 months after initiation, 7 patients remained on the diet, and all of them had a > 90% seizure reduction, including five became seizure free. No significant variables were related to the efficacy. Most complications were mild and reversible by conservative treatment. Gastrointestinal disturbances were the main complications, which included vomiting, diarrhea, constipation, and abdominal cramp. Severe complications occurred in four cases, including severe metabolic disturbances and severe pneumonia.


CONCLUSION
The KD is a safe and effective alternative therapy for intractable childhood epilepsy.