Focal non-motor seizures and subsequent focal motor seizures as the main clinical expression of GLUT-1 deficiency.

Abstract

The seizure type most frequently described in GLUT1 deficiency is generalized (mainly absence). We report the case of a young boy who, as the main clinical manifestation presented with focal non-motor, and then focal motor seizures. At the age of 3months episodes of face pallor/cyanosis and hypotonus lasting about 1min, occurred. They were initially misdiagnosed as gastroesophageal reflux. These episodes disappeared spontaneously at 6months of age. At 12months, episodes similar to the previous ones reappeared. A few months later, a cluster of several episodes manifest as impaired responsiveness and vomiting occurred. The patient initially performed long-term video-EEG monitoring (LTVEM) however, no seizures were captured. During a second hospitalization for LTVEM, a focal to bilateral clonic seizure was recorded. Brain MRI was normal. Next Generation Sequencing (NGS) panel for genes associated with epilepsy showed a de novo mutation of SCL2A1 gene. The CSF showed glucose of 41mg/dL, and the CSF/serum glucose ratio was equal to 0.46. The ketogenic diet was started with optimal efficacy in seizure control. Meal-sensitivity in childhood onset focal seizures may be associated with GLUT-1 deficiency syndrome that can be confirmed by biochemical analysis on blood and CSF following diagnostic genetic study.