Predictors of Ketogenic Diet Efficacy in Children Based on the Electroencephalogram (EEG)

It is unclear whether electrographic features are predictive of ketogenic diet efficacy and how evolution of electroencephalogram (EEG) findings correlates with clinical improvement. We aimed to identify predictors for clinical seizure reduction on the diet as it correlates with serial EEGs. We reviewed 89 patients on the diet at Children's Medical Center from 2005 to 2012. We developed scoring criteria to analyze EEG characteristics (2 scales: 0-3 for encephalopathy; 0-6 for interictal discharges). Those with the lowest encephalopathy scores on last EEG strongly correlated with seizure reduction in patients with >95% seizure reduction (P = .002). A change in encephalopathy scores in those with moderate-severe encephalopathy on first EEG also correlated with >95% reduction in seizures (P = .009). This supports the theory that serial EEGs can be helpful in predicting positive therapeutic outcomes on the diet. Of 43 patients with both initial and follow-up EEGs, 27 had a decrease in interictal epileptic discharge frequency, though this was not significant (P = .434).