Glucose Transporter 1 Deficiency: A Treatable Cause of Opsoclonus and Epileptic Myoclonus.

BACKGROUND

Epileptic myoclonus in infancy is associated with various pathological conditions. In the absence of an identifiable central nervous system lesion, an underlying metabolic genetic cause is often suspected.

PATIENTS: We describe two infants with glucose transporter 1 deficiency syndrome who presented with epileptic myoclonus. One infant presented with an electroclinical phenotype mimicking benign myoclonic epilepsy of infancy; the other infant had a novel mutation and presented with opsoclonus and epileptic myoclonus with a robust response to high-dose steroids. Both infants began the ketogenic diet after the diagnosis of glucose transporter 1 deficiency syndrome, with good yet variable treatment responses.

CONCLUSIONS

These infants demonstrate that an evaluation for glucose transporter 1 deficiency syndrome is warranted in patients presenting with an electroclinical picture compatible with benign myoclonic epilepsy of infancy as well as in patients with intractable epilepsy who demonstrate a significant response to steroid therapy.