Glut1 deficiency syndrome (Glut1DS) is a brain energy failure syndrome caused by impaired glucose transport across brain tissue barriers. Glucose diffusion across tissue barriers is facilitated by a family of proteins including glucose transporter type 1 (Glut1). Patients are treated effectively with ketogenic diet therapies (KDT) that provide a supplemental fuel, namely ketone bodies, for brain energy metabolism. The increasing complexity of Glut1DS, since its original description in 1991, now demands an international consensus statement regarding diagnosis and treatment. International experts (n = 23) developed a consensus statement utilizing their collective professional experience, responses to a standardized questionnaire, and serial discussions of wide‐ranging issues related to Glut1DS. Key clinical features signaling the onset of Glut1DS are eye‐head movement abnormalities, seizures, neurodevelopmental impairment, deceleration of head growth, and movement disorders. Diagnosis is confirmed by the presence of these clinical signs, hypoglycorrhachia documented by lumbar puncture, and genetic analysis showing pathogenic SLC2A1 variants. KDT represent standard choices with Glut1DS‐specific recommendations regarding duration, composition, and management. Ongoing research has identified future interventions to restore Glut1 protein content and function. Clinical manifestations are influenced by patient age, genetic complexity, and novel therapeutic interventions. All clinical phenotypes will benefit from a better understanding of Glut1DS natural history throughout the life cycle and from improved guidelines facilitating early diagnosis and prompt treatment. Often, the presenting seizures are treated initially with antiseizure drugs before the cause of the epilepsy is ascertained and appropriate KDT are initiated. Initial drug treatment fails to treat the underlying metabolic disturbance during early brain development, contributing to the long‐term disease burden. Impaired development of the brain microvasculature is one such complication of delayed Glut1DS treatment in the postnatal period. This international consensus statement should facilitate prompt diagnosis and guide best standard of care for Glut1DS throughout the life cycle.

Glut1 deficiency syndrome (Glut1 DS) was originally described in 1991 as a developmental encephalopathy characterized by infantile onset refractory epilepsy, cognitive impairment, and mixed motor abnormalities including spasticity, ataxia, and dystonia. The clinical condition is caused by impaired glucose transport across the blood brain barrier. The past 5 years have seen a dramatic expansion in the range of clinical syndromes that are recognized to occur with Glut1 DS. In particular, there has been greater recognition of milder phenotypes. Absence epilepsy and other idiopathic generalized epilepsy syndromes may occur with seizure onset in childhood or adulthood. A number of patients present predominantly with movement disorders, sometimes without any accompanying seizures. In particular, paroxysmal exertional dyskinesia is now a well-documented clinical feature that occurs in individuals with Glut1 DS. A clue to the diagnosis in patients with paroxysmal symptoms may be the triggering of episodes during fasting or exercise. Intellectual impairment may range from severe to very mild. Awareness of the broad range of potential clinical phenotypes associated with Glut1 DS will facilitate earlier diagnosis of this treatable neurologic condition. The ketogenic diet is the mainstay of treatment and nourishes the starving symptomatic brain during development.

Our objective is to characterize the long-term course of Glut1 deficiency syndrome. Longitudinal outcome measures, including Columbia Neurological Scores, neuropsychological tests, and adaptive behavior reports, were collected for 13 participants with Glut1 deficiency syndrome who had been followed for an average of 14.2 (range = 8.9-23.6) years. A parent questionnaire assessed manifestations throughout development. The 6-Minute Walk Test captured gait disturbances and triggered paroxysmal exertional dyskinesia. All longitudinal outcomes remained stable over time. Epilepsy dominated infancy and improved during childhood. Dystonia emerged during childhood or adolescence. Earlier introduction of the ketogenic diet correlated with better long-term outcomes on some measures. Percent-predicted 6-Minute Walk Test distance correlated significantly with Columbia Neurological Scores. We conclude that Glut1 deficiency syndrome is a chronic condition, dominated by epilepsy in infancy and by movement disorders thereafter. Dietary treatment in the first postnatal months may effect improved outcomes, emphasizing the importance of early diagnosis and treatment.

Exposure to an enriched environment in weanling rats significantly improves visual-spatial learning. Even following SE, an enriched environment enhances cognitive function. An increase in neurogenesis and activation of transcription factors may contribute to this enhanced visual-spatial memory.

Summary:Background: Nonconvulsive status epilepticus (NCSE) is a highly heterogeneous clinical condition that is understudied in the pediatric population.Objective: To analyze the epidemiological, clinical, and electroencephalograpic features in pediatric patients with NCSE.