Epilepsy and glucose transporter 1 deficiency syndrome

Abstract

Glucose transporter 1 deficiency syndrome (GLUT-1 DS) is a unique genetic syndrome representing a severe metabolic encephalopathy, as a result, of insufficient glucose transport into the brain. Infantile onset seizures, acquired microcephaly, spasticity, ataxia, dystonia and mental retardation are the cardinal features of the syndrome. Over the years, the clinical spectrum of GLUT-1 DS has been expanded beyond the original phenotype. Clinical features of seizures present with a wide spectrum, however generalized seizures are reported as the most common seizure types in the patients received diagnosis of GLUT-1 DS. In recent years, there are number of epilepsy syndromes described in association with GLUT-1 DS has been shown to be the underlying cause for 10% of early onset absence epilepsy, 5% of Myoclonic astatic epilepsy (MAE) and 1% of idiopathic generalized epilepsies. Seizures are often remained refractory despite the treatment with a number of antiepileptic medications. Valproate and benzodiazepines are relatively contraindicated for the treatment of seizures in this syndrome. Ethanol and caffeine also inhibits GLUT-1 transport activity and may exacerbate seizures. Ketogenic diet remains the most effective treatment in order to meet the energy demand of developing brain. GLUT-1 DS should be suspected in the individuals with family history of idiopathic generalized epilepsy and/or paroxysmal dyskinesia. Moreover, the families with absence epilepsy with a wide range of age of onset or seizure types should also be screened for GLUT-1 DS.