SUMMARYPurpose: To report the efficacy, safety, and tolerability of the low glycemic index treatment (LGIT) in pediatric epilepsy. Methods: A retrospective chart review was performed on patients initiating the LGIT at the Massachusetts General Hospital between January 2002 and June 2008. Demographic and clinical information including seizure type, baseline seizure frequency, medications, blood chemistries, side effects, and anthropometrics were collected. Initiation of the LGIT was done in an outpatient setting. Patients were educated by a dietitian to restrict foods with high glycemic index and to limit total daily carbohydrates to 40-60 g. Change in seizure frequency was assessed at 1-, 3-, 6-, 9-, and 12-month follow-up intervals. Results: Seventy-six children were included in the study. Eighty-nine percent had intractable epilepsy ( ‡3 antiepileptic drugs). A greater than 50% reduction from baseline seizure frequency was observed in 42%, 50%, 54%, 64%, and 66% of the population with follow-up available at 1, 3, 6, 9, and 12 months, respectively. Increased efficacy was correlated with lower serum glucose levels at some time points, but not with b-hydroxybutyrate (BOHB) changes or ketosis status at any time point. Only three patients reported side effects (transient lethargy). Blood urea nitrogen (BUN) was elevated in approximately one-third of follow-up laboratory studies. No significant changes were seen in body mass index (BMI) or BMI z-score at any followup interval. The most cited reason for treatment discontinuation was the restrictiveness of the diet, in 18 patients (24%). Conclusion: The LGIT was associated with reduced seizure frequency in a large fraction of patients, with limited side effects.

SUMMARYDespite the substantial efficacy of the ketogenic diet (KD) in treating refractory epilepsy, use of the KD remains limited because of difficulties in implementation and tolerability. An effective alternative dietary approach is a low glycemic index treatment (LGIT), which liberalizes the extreme carbohydrate restriction of the KD but restricts the type of carbohydrate-containing foods to those that produce relatively small changes in blood glucose. Foods with a "glycemic index" of less than 50 produce less than half the area-under-the-curve elevation of blood glucose compared to a reference food. The LGIT approach produces comparable efficacy to the classic KD, but tolerability is improved and implementation is much simpler. The LGIT appears to be a viable first-line dietary therapy for epilepsy. KEY WORDS: Glycemic index, Low glycemic index treatment, Refractory epilepsy, Dietary therapy.Developed in the 1920s, the classic ketogenic diet (KD) is arguably the most effective treatment available for medically refractory epilepsy. Over the past 80 years, numerous case series of the classic KD, performed largely in children, have shown that up to one-third of patients who initiate the KD experience a dramatic decrease in seizure frequency (Bailey et al., 2005). However, there are several limitations to the availability, implementation, and maintenance of the KD.Traditional implementation of the KD required an initial fast of 24-48 h followed by gradual introduction of the KD over several days during an inpatient hospitalization. Ideally, calculation of the KD is performed by a skilled KD dietitian who educates the child and family in how to implement and maintain the KD, and who also prepares numerous individualized meal plans to meet the child's protein, fat, and carbohydrate goals to 0.1 g precision. Due to several factors, including a relatively limited number of experienced dietitians, difficulty with reimbursement, and the intensity of labor in initiating and maintaining patients on a classic KD, access to this diet remains limited. Even when the KD is available, its restrictiveness often makes it difficult for a child and family to adhere to, and being on

Cortical tubers are very common in tuberous sclerosis complex (TSC) and widely vary in size, appearance and location. The relationship between tuber features and clinical phenotype is unclear. The aim of the study is to propose a classification of tuber types along a spectrum of severity, using magnetic resonance imaging (MRI) characteristics in 35 patients with TSC and history of epilepsy, and to investigate the relationship between tuber types and genetics, as well as clinical manifestations. Three types of tubers were identified based on the MRI signal intensity of their subcortical white matter component. (1) Tubers Type A are isointense on volumetric T1 images and subtly hyperintense on T2 weighted and fluid-attenuated inversion recovery (FLAIR); (2) Type B are hypointense on volumetric T1 images and homogeneously hyperintense on T2 weighted and FLAIR; (3) Type C are hypointense on volumetric T1 images, hyperintense on T2 weighted, and heterogeneous on FLAIR characterized by a hypointense central region surrounded by a hyperintense rim. Based on the dominant tuber type present, three distinct patient groups were also identified: Patients with Type A tuber dominance have a milder phenotype. Patients with Type C tuber dominance have more MRI abnormalities such as subependymal giant cell tumors, and were more likely to have an autism spectrum disorder, a history of infantile spasms, and a higher frequency of epileptic seizures, compared to patients who have a dominance in Type B tubers, and especially to those with a Type A dominance.