Use of dietary therapies amongst patients with GLUT1 deficiency syndrome

GLUT-1 deficiency syndrome (GLUT1DS) is a neurologic disorder manifesting as epilepsy, abnormal movements, and cognitive delay. The currently accepted treatment of choice is the classic 4:1 ratio ketogenic diet.

A 2-page survey was distributed to all attendees of a family-centered conference for GLUT1DS in July 2015. The surveys were completed by parents, collected anonymously, and information analyzed in a database.

Surveys were received from 92 families, of which 90 (98%) had been treated with dietary therapies. Diets used were extremely varied: 59 were treated with the classic ketogenic diet (KD), 29 with the Modified Atkins Diet (MAD), 4 with the Medium-chain Triglyceride (MCT) Diet and 2 with the low glycemic index treatment. The mean diet duration was 5.5 years (range: 1 month-20 years). Of those with seizures, 95% of the children had >50% seizure reduction and 80% had >90% seizure reduction. Children who were seizure-free were currently younger on average (8.2 vs. 11.6 years, p=0.01) and slightly younger at GLUT1DS diagnosis (3.8 vs. 5.3 years, p=0.05). There was an equal percentage of children seizure-free receiving the KD/MCT Diets compared to the MAD/Low Glycemic Index Treatment (74% vs. 63%, p=0.30). The majority (64%) were not receiving anticonvulsants.

This represents the largest series of KD experience in children with GLUT1DS. Nearly all patients surveyed were on dietary therapies for long durations with reported excellent seizure control, often without anticonvulsant drugs. Several different ketogenic diets were utilized with similar efficacy. Early diagnosis and treatment were correlated with success.