Accuracy of Flash Glucose Monitoring in a Patient with Dravet Syndrome on a Ketogenic Diet

Abstract

We herein report the case of a 3-year-old girl with severe myoclonic epilepsy of infancy known as Dravet syndrome (DS) on a ketogenic diet (KD) whose glucose concentrations were controlled by using a flash glucose monitoring system. Two-hundred ninety-three events of moderate hypoglycemia with a minimum of 45 mg/dL, not related to day or night, were recorded during the observational period. Hypoglycemia rate declined from 24.5% of all measurements to 11.8% over time; one hypoglycemia-associated seizure and one seizure due to ketone concentrations below the therapeutic range were observed. In summary, this case report broadens our understanding of hypoglycemia risk in patients with DS on a KD. Especially in childhood, the painless and easy detection of low glucose concentrations might lead to improved cognitive performance, and the reduction of hypoglycemia-induced seizures.

Monitoring Glucose Concentrations in Children with Epilepsy on a Ketogenic Diet

“…Our results showed that hypoglycemia is an adverse effect especially when starting the KD. This is in line with previous studies [ 19 , 20 ]. However, clinical studies reported a good tolerance of induced hypoglycemia [ 35 ] and the overall hypoglycemia rates per day of all patients were quite low.…”

“…Our results are, therefore, in line with our previous findings in a pediatric patient with Dravet Syndrome using an FGM system over an observational period of six months, where a decline in the hypoglycemia rate three months after the beginning of the KD was shown [ 19 ]. In addition to emesis and food refusal, hypoglycemia, as an adverse side effect of the KD, was frequently observed in younger children [ 11 ].…”

“…Greater ketone concentrations within the therapeutic range are essential for an adequate ketosis, which plays a major role in the pathophysiological basis of the KD. However, as we found a weak negative correlation between glucose and ketone concentration, comparable to our previous findings [ 19 ], glucose levels should be monitored especially when ketone concentrations are high.…”

“…The advantages of the FGM are the precision and stability of the measurements, as well as usage for 14 days without calibration [ 18 ]. The effectiveness of using a FGM during the KD was previously shown in a patient with Dravet Syndrome [ 19 ], and with continuous glucose measurement in a patient with intractable epilepsy [ 20 ], highlighting that the hypoglycemia rate is increased, particularly at the beginning of the KD.…”