Hemidistonía y hemicorea en un paciente pediátrico con déficit del transportador de glucosa de tipo 1 / Hemidystonia and hemichorea in a pediatric patient with glucose transporter type 1 deficiency

El síndrome de deficiencia del transportador de glucosa cerebral de tipo 1 es una enfermedad neurometabólica rara en pediatría. Existe un fenotípico clásico (85 %) y otro no clásico (15 %). Ambos fenotipos se asocian con hipoglucorraquia. Se identifican múltiples mutaciones en el gen SLC2A1. El tratamiento es la terapia cetogénica. Se presenta un varón que comenzó a los cuatro años con hemicorea y hemidistonía medicado con anticonvulsivantes sin respuesta clínica, por lo que consultó nuevamente a los seis años. Con sospecha diagnóstica de síndrome de déficit de glut-1 atípico se realizó punción lumbar; el diagnóstico se confirmó por la presencia de hipoglucorraquia. Inmediatamente después de iniciar la dieta cetogénica, el paciente no presentó más movimientos anormales durante los siguientes 8 años hasta la actualidad, ya cumplidos los 14 años.

Glucose transporter type 1 deficiency syndrome is a rare pediatric neurometabolic disorder. There are two phenotypes: the classical phenotype (85%) and the non-classic (15%). Both phenotypes are associated with hypoglycorrhachia. Multiple mutations are described in the SCL2A1 gene. The treatment is the ketogenic diet. We report a case of a four-year-old male patient who started with hemichorea and hemidystonia and was medicated with drugs for seizures without clinical response, that's why his parents made another pediatric consultation at his six-year-old. With the suggestive clinical findings of glucose transporter type 1 deficiency syndrome the lumbar puncture was made confirming the diagnosis. Immediately after starting the ketogenic diet the patient stopped making abnormal movements up to the moment when he is fourteen years old, eight years after.

Ketogenic dietary therapies for epilepsy: Experience in 160 patients over 18 years.

AIM: Ketogenic dietary therapies (KDT) produce anticonvulsant and neuroprotective effects, reduce seizures and improve the cognitive state in patients with epilepsy. Our purpose was to evaluate the effects of KDT in children with refractory epilepsy (effectiveness, side effects, impact on nutritional status and growth). METHODS: A retrospective and prospective observational descriptive study was conducted in a Spanish tertiary hospital (January 2000 to December 2018). One hundred sixty pediatric patients with epilepsy were treated with KDT (82 males; mean age 5 years 9 months). Seizures, anti-epileptic drugs, anthropometric measures, side effects, and laboratory assessment were monitored baseline and at 3, 6, 12 and 24 months after the onset of KDT. RESULTS: In these time intervals, the seizure-free patients were: 13.7, 12.5, 14.4 and 10.6%, respectively, and a reduction of seizures ≥ 50% was achieved in 41.9, 37.5, 28.7 and 16.2%. Side effects were frequent, especially digestive disorders, hypercalciuria, hypoglycemia, hepatic dysfunction and dyslipidemia. Prealbumin, retinol binding protein, vitamin A and magnesium decreased significantly. Height was affected, especially in children below 2 years. CONCLUSIONS: KDT are effective for refractory epilepsy in children. However, adverse effects are frequent, and it may affect nutritional status and growth.

Terapias dietéticas cetogénicas en epilepsia: experiencia en 160 pacientes durante 18 años / Ketogenic dietary therapies for epilepsy: Experience in 160 patients over 18 years

Introducción: Las terapias dietéticas cetogénicas (TDC) tienen efecto neuroprotector y anticonvulsivante, reducen las crisis epilépticas y mejoran el estado cognitivo en pacientes epilépticos. Nuestro propósito fue evaluar los efectos de las TDC en niños con epilepsia refractaria (eficacia, efectos secundarios, impacto en el estado nutricional y crecimiento).Métodos: Se realizó un estudio observacional descriptivo retrospectivo y prospectivo en un hospital terciario español (enero de 2000-diciembre de 2018). Ciento sesenta pacientes pediátricos con epilepsia fueron tratados con TDC (82 varones; edad media 5 años 9 meses). Las convulsiones, los fármacos antiepilépticos, la antropometría, los efectos secundarios y los parámetros analíticos se controlaron al inicio del tratamiento y a los 3, 6, 12 y 24 meses.Resultados: En estos intervalos los pacientes libres de crisis fueron: 13,7%, 12,5%, 14,4% y 10,6%, respectivamente, lográndose una reducción de las convulsiones≥50% en el 41,9%, 37,5%, 28,7% y 16,2%. Los efectos secundarios fueron frecuentes, especialmente trastornos digestivos, hipercalciuria, hipoglucemia, disfunción hepática y dislipidemia. La prealbúmina, la proteína de unión al retinol, la vitamina A y el magnesio disminuyeron significativamente. La talla se vio afectada, especialmente en niños menores de 2 años.Conclusiones: Las TDC son efectivas para la epilepsia refractaria infantil. Sin embargo, los efectos adversos son frecuentes y pueden afectar al estado nutricional y al crecimiento. (AU)

Aim: Ketogenic dietary therapies (KDT) produce anticonvulsant and neuroprotective effects, reduce seizures and improve the cognitive state in patients with epilepsy. Our purpose was to evaluate the effects of KDT in children with refractory epilepsy (effectiveness, side effects, impact on nutritional status and growth).Methods: A retrospective and prospective observational descriptive study was conducted in a Spanish tertiary hospital (January 2000 to December 2018). One hundred sixty pediatric patients with epilepsy were treated with KDT (82 males; mean age 5 years 9 months). Seizures, anti-epileptic drugs, anthropometric measures, side effects, and laboratory assessment were monitored baseline and at 3, 6, 12 and 24 months after the onset of KDT.Results: In these time intervals, the seizure-free patients were: 13.7, 12.5, 14.4 and 10.6%, respectively, and a reduction of seizures≥50% was achieved in 41.9, 37.5, 28.7 and 16.2%. Side effects were frequent, especially digestive disorders, hypercalciuria, hypoglycemia, hepatic dysfunction and dyslipidemia. Prealbumin, retinol binding protein, vitamin A and magnesium decreased significantly. Height was affected, especially in children below 2 years.Conclusions: KDT are effective for refractory epilepsy in children. However, adverse effects are frequent, and it may affect nutritional status and growth.(AU)

Diagnostic and Clinical Manifestation Differences of Glucose Transporter Type 1 Deficiency Syndrome in a Family with SLC2A1 Gene Mutation.

Glucose transporter type 1 deficiency syndrome is a rare genetic disease that manifests neurological symptoms such as mental impairment or movement disorders, mostly seen in pediatric patients. Here, we highlight the main symptoms, diagnostic difficulties, and genetic correlations of this disease based on different clinical presentations between the members of a family carrying the same mutation. In this report, we studied siblings-a 5-year-old girl and a 6-year-old boy-who were admitted to a pediatric ward with various neurological symptoms. Different diagnostic procedures such as lumbar puncture, electroencephalography, and MRI of the brain were performed on these patients. Whole genome sequencing identified mutations in the SLC2A1 and GLUT1-DS genes, following which a ketogenic diet was implemented. This diet modification resulted in a good clinical response. Our case report reveals patients with the same genetic mutations having distinctive clinical manifestations.

NGS-Based Diagnosis of Treatable Neurogenetic Disorders in Adults: Opportunities and Challenges.

The identification of neurological disorders by next-generation sequencing (NGS)-based gene panels has helped clinicians understand the underlying physiopathology, resulting in personalized treatment for some rare diseases. While the phenotype of distinct neurogenetic disorders is generally well-known in childhood, in adulthood, the phenotype can be unspecific and make the standard diagnostic approach more complex. Here we present three unrelated adults with various neurological manifestations who were successfully diagnosed using NGS, allowing for the initiation of potentially life-changing treatments. A 63-year-old woman with progressive cognitive decline, pyramidal signs, and bilateral cataract was treated by chenodeoxycholic acid following the diagnosis of cerebrotendinous xanthomatosis due to a homozygous variant in CYP27A1. A 32-year-old man with adult-onset spastic paraplegia, in whom a variant in ABCD1 confirmed an X-linked adrenoleukodystrophy, was treated with corticoids for adrenal insufficiency. The third patient, a 28-year-old woman with early-onset developmental delay, epilepsy, and movement disorders was treated with a ketogenic diet following the identification of a variant in SLC2A1, confirming a glucose transporter type 1 deficiency syndrome. This case study illustrates the challenges in the timely diagnosis of medically actionable neurogenetic conditions, but also the considerable potential for improving patient health through modern sequencing technologies.

[Ketogenic dietary therapies for epilepsy: Experience in 160 patients over 18 years]. / Terapias dietéticas cetogénicas en epilepsia: experiencia en 160 pacientes durante 18 años.

AIM: Ketogenic dietary therapies (KDT) produce anticonvulsant and neuroprotective effects, reduce seizures and improve the cognitive state in patients with epilepsy. Our purpose was to evaluate the effects of KDT in children with refractory epilepsy (effectiveness, side effects, impact on nutritional status and growth). METHODS: A retrospective and prospective observational descriptive study was conducted in a Spanish tertiary hospital (January 2000 to December 2018). One hundred sixty pediatric patients with epilepsy were treated with KDT (82 males; mean age 5 years 9 months). Seizures, anti-epileptic drugs, anthropometric measures, side effects, and laboratory assessment were monitored baseline and at 3, 6, 12 and 24 months after the onset of KDT. RESULTS: In these time intervals, the seizure-free patients were: 13.7, 12.5, 14.4 and 10.6%, respectively, and a reduction of seizures≥50% was achieved in 41.9, 37.5, 28.7 and 16.2%. Side effects were frequent, especially digestive disorders, hypercalciuria, hypoglycemia, hepatic dysfunction and dyslipidemia. Prealbumin, retinol binding protein, vitamin A and magnesium decreased significantly. Height was affected, especially in children below 2 years. CONCLUSIONS: KDT are effective for refractory epilepsy in children. However, adverse effects are frequent, and it may affect nutritional status and growth.

Ketogenic diet for infants with epilepsy: A literature review.

The ketogenic diet (KD) is an established, nonpharmacological treatment for drug-resistant epilepsy (DRE). Actually, KD and its variants have been shown to be elective and resolute for patients with glucose transporter type 1 (GLUT1) deficiency. The aim of this review was to study the use of KD and its variants in infancy, including the neonatal age, and demonstrate the safety and efficacy of this treatment in patients with the age of 0-23 months affected by DRE already subjected to pharmacological approach attempts. A literature search was conducted using PubMed as the medical database source. We used the age limit of 0-23 months, and we considered only articles published between the years 2015 and 2018, in light of increasing interest worldwide in the use of KD and its variants to manage DRE. We included 52 publications: 1 Cochrane study, 22 retrospective studies, 9 prospective studies, 4 randomized controlled trials (RCTs), 12 clinical cases, and 4 clinical reviews. Literature data showed that KD and its variants are safe and useful in patients with the age of 0-23 months with DRE. Classical KD is of first choice in the treatment of GLUT1 deficiency. Earlier introduction of KD in GLUT1 promises a better outcome and a decrease in seizure frequency in these patients.

Use of Remote Monitoring by E-mail for Long-Term Management of the Classic Ketogenic Diet.

The classic ketogenic diet (cKD) requires constant nutritional monitoring over time both to ensure its effectiveness and to reduce the likelihood of short- and long-term adverse effects. We retrospectively described the use of remote monitoring by e-mail during the first year of follow-up on cKD in 34 children (47% males; age range: 2-17 years) diagnosed with drug-resistant epilepsy (DRE; n = 14) or glucose transporter type 1 deficiency syndrome (GLUT1-DS; n = 20). All the e-mails were evaluated analyzing their frequency and content at 3, 6 and 12 months. Three families never sent e-mails. A median of 36.0 (IQR 23.0-64.0) e-mails per family were sent during the 12 follow-up months by the 31 patients. GLUT1-DS patients sent a greater number of e-mails than the DRE group (median 39.0 (IQR 25.5-56.5) vs. median 26.0 (IQR 19.0-65.0)). At the end of the follow-up period, a greater number of e-mails had been exchanged between the nutritional team and the families belonging to the group that increased its linear growth (median 83.5; IQR 48.0-102.0), compared to the other ones. Constant remote monitoring by e-mail could be a feasible and effective way for a better cKD management.

Glucose transporter type 1 deficiency syndrome associated with autoantibodies to glutamate receptors.

BACKGROUND: The clinical spectrum of glucose transporter type 1 deficiency syndrome (GLUT1DS) has broadened, with increasing recognition of a milder phenotype. Antibodies targeting the subunits of glutamate receptors (GluRs), including GluN1, GluN2B, and GluD2, have been detected in various neurological disorders. Anti-GluD2 antibodies in particular may be associated with cerebellar symptoms. CASE REPORT: A 3-year-5-month-old boy with normal development exhibited myoclonus refractory to antiepileptic drugs from one year ago. He developed tremor and ataxia. Cerebrospinal fluid (CSF) revealed fasting-state glucose 50 mg/dl (CSF/blood glucose ratio of 0.50). Single photon emission computed tomography with 123I-iodoamphetamine revealed hypoperfusion in the cerebellum. At age 4 years and 5 months, treatment with intravenous methylprednisolone (IVMP) relieved his symptoms and improved the cerebellar hypoperfusion. However, his symptoms reappeared at age 5 years and 1 month. Treatment with IVMP was repeated, resulting in transient disappearance of symptoms. At age 6 years and 9 months, he was diagnosed with GLUT1DS by genetic analysis, and treatment with modified Atkins diet was started with efficacy. Levels of anti-GluN1, -GluN2B, and -GluD2 antibodies in the serum and CSF were measured 4 times. All antibodies in the CSF were elevated over 2 standard deviations above controls, and the levels fluctuated along with the severity of his symptoms. The level of anti-GluD2 antibodies in CSF declined to the normal range only after starting the modified Atkins diet. CONCLUSION: Treatment with IVMP transiently improved this patient's symptoms. Levels of anti-GluR antibodies may be associated with symptom severity.

Impact of the Ketogenic Diet on Linear Growth in Children: A Single-Center Retrospective Analysis of 34 Cases.

Data on the impact of the ketogenic diet (KD) on children's growth remain controversial. Here, we retrospectively investigated the occurrence of linear growth retardation in 34 children (47% males; age range: 2-17 years) diagnosed with drug-resistant epilepsy (DRE; n = 14) or glucose transporter type 1 deficiency syndrome (GLUT1-DS; n = 20) who had been treated with the KD for 12 months. The general characteristics of children with and without growth retardation were also compared. All participants received a full-calorie, traditional KD supplemented with vitamins, minerals, and citrate. Most children (80%; 11/14 in the DRE subgroup and 16/20 in the GLUT1-DS subgroup) treated with the KD did not show growth retardation at 12 months. Although participants with and without delay of growth did not differ in terms of baseline clinical characteristics, dietary prescriptions, or supplementation patterns, marked ketosis at 12 months tended to occur more frequently in the latter group. Altogether, our results indicate that growth retardation may occur in a minority of children treated with the KD. However, further research is required to identify children at risk and to clarify how increased ketones levels may affect endocrine pathways regulating growth during KD administration.

Glut1 deficiency is a rare but treatable cause of childhood absence epilepsy with atypical features.

Glucose transporter type 1 deficiency syndrome (GLUT1-DS) is a rare genetic disorder caused by pathogenic variants in SLC2A1, resulting in impaired glucose uptake through the blood-brain barrier. Our objective is to analyze the frequency of GLUT1-DS in patients with absences with atypical features. Sequencing analysis and detection of copy number variation of the SLC2A1 gene was carried out in patients with atypical absences including: early-onset absence, intellectual disability, additional seizure types, refractory epilepsy, associated movement disorders, as well as those who have first-degree relatives with absence epilepsy or atypical EEG ictal discharges. Of the 43 patients analyzed, pathogenic variations were found in 2 (4.6%). Six atypical characteristics were found in these 2 patients. The greater the number of atypical characteristics presenting in patients with absence seizures, the more likely they have a SLC2A1 mutation. Although GLUT1-DS is an infrequent cause of absence epilepsy, recognizing this disorder is important, since initiation of a ketogenic diet can reduce the frequency of seizures, the severity of the movement disorder, and also improve the quality of life of the patients and their families.

Long-Term Effect of GPi-DBS in a Patient With Generalized Dystonia Due to GLUT1 Deficiency Syndrome.

Treatment outcomes from pallidal deep brain stimulation are highly heterogeneous reflecting the phenotypic and etiologic spectrum of dystonia. Treatment stratification to neurostimulation therapy primarily relies on the phenotypic motor presentation; however, etiology including genetic factors are increasingly recognized as modifiers of treatment outcomes. Here, we describe a 53 year-old female patient with a progressive generalized dystonia since age 25. The patient underwent deep brain stimulation of the globus pallidus internus (GPi-DBS) at age 44. Since the clinical phenotype included mobile choreo-dystonic features, we expected favorable therapeutic outcome from GPi-DBS. Although mobile dystonia components were slightly improved in the long-term outcome from GPi-DBS the overall therapeutic response 9 years from implantation was limited when comparing "stimulation off" and "stimulation on" despite of proper electrode localization and sufficient stimulation programming. In order to further understand the reason for this limited motor symptom response, we aimed to clarify the etiology of generalized dystonia in this patient. Genetic testing identified a novel heterozygous pathogenic SLC2A1 mutation as cause of glucose transporter type 1 deficiency syndrome (GLUT1-DS). This case report presents the first outcome of GPi-DBS in a patient with GLUT1-DS, and suggests that genotype relations may increasingly complement phenotype-based therapy stratification of GPi-DBS in dystonia.

Individualizing Treatment Approaches for Epileptic Patients with Glucose Transporter Type1 (GLUT-1) Deficiency.

Monogenic and polygenic mutations are important contributors in patients suffering from epilepsy, including metabolic epilepsies which are inborn errors of metabolism with a good respond to specific dietetic treatments. Heterozygous variation in solute carrier family 2, facilitated glucose transporter member 1 (SLC2A1) and mutations of the GLUT1/SLC2A2 gene results in the failure of glucose transport, which is related with a glucose type-1 transporter (GLUT1) deficiency syndrome (GLUT1DS). GLUT1 deficiency syndrome is a treatable disorder of glucose transport into the brain caused by a variety of mutations in the SLC2A1 gene which are the cause of different neurological disorders also with different types of epilepsy and related clinical phenotypes. Since patients continue to experience seizures due to a pharmacoresistance, an early clinical diagnosis associated with specific genetic testing in SLC2A1 pathogenic variants in clinical phenotypes could predict pure drug response and might improve safety and efficacy of treatment with the initiation of an alternative energy source including ketogenic or analog diets in such patients providing individualized strategy approaches.

Glucose Transporter Type 1 Deficiency Syndrome: Developmental Delay and Early-Onset Ataxia in a Novel Mutation of the SLC2A1 Gene.

Glucose transporter type 1 deficiency syndrome (GLUT1-DS) was first described by De Vivo in 1991, and the classic clinical manifestations include infantile epilepsy, developmental delay, and acquired microcephaly. A neurological complex disorder including elements of hypotonia, spasticity, ataxia, and dystonia can frequently be present. GLUT1-DS is an inborn error of metabolism caused by impaired glucose transport through blood-brain barrier in the majority of patients because of mutation of solute carrier family 2 (facilitated glucose transporter) member 1 gene (SLC2A1), encoding the transporter protein. We report a 6-year-old girl with GLUT1-DS, which is caused by a novel heterozygous variant c.109dupC of the SLC2A1 gene. The dominating clinical features were ataxia, epilepsy started at 4 years, acquired microcephaly, and mild intellectual disability. Treatment with ketogenic diet showed clinical improvement with the reduction of ataxia and seizure control in a 10-month follow-up period.

Outcome of ketogenic diets in GLUT1 deficiency syndrome in Japan: A nationwide survey.

OBJECTIVES: To evaluate the outcome of ketogenic diets (KDs) in patients with glucose transport type 1 deficiency syndrome (GLUT1DS) in Japan. METHODS: A nationwide survey for GLUT1DS was conducted by sending questionnaires to board-certified pediatric neurologists nationwide to obtain clinical and laboratory data. RESULTS: Among 39 patients whose diagnosis was confirmed molecularly or by the 3-O-methylglucose uptake assay, 31 were treated with KDs for longer than 1month. Seventeen patients (55%) were on the modified Atkins diet, 11 (35%) were on the classic KD, and 3 were on the medium-chain triglyceride (MCT) diet. The median values and ranges of serum ß-hydroxybutyrate levels in patients on the modified Atkins diet, classic KD and MCT diet were 2.5mM (0.75-4.1), 1.7mM (0.23-3.5) and 2.6mM (1.5-3.0), respectively. The KDs were effective on seizures (80%), aggravation after fasting (80%) and ataxia (79%). Thus, ataxia was as responsive as seizures. Two patients on the classic KD with a ketogenic ratio as low as 1:1 showed improvement in neurological symptoms. The development or intelligence quotient measured using the same psychological scales before and after the KDs in 9 patients did not show a significant improvement; the median quotients before and after the diets were 40 (12-91) and 46 (12-67). CONCLUSION: The KDs were most effective on seizures, transient aggravation after fasting and ataxia. The efficacy on intellectual development was equivocal. The modified Atkins diet was more commonly used for GLUT1DS in this study, and its ketogenicity was equivalent to the classic KD.

Glut1 deficiency syndrome: Absence epilepsy and La Soupe du Jour.

For some time, paediatric neurologists have recognised glucose transporter type 1 (GluT1) deficiency syndrome as a cause of intractable infantile seizures, microcephaly, developmental delay and hypoglycorrhachia in the presence of a normal plasma glucose. It is caused by mutations in the SLC2A1 gene, coding for GluT1, leading to a reduction in the available glucose transporter sites; it responds to the ketogenic diet. Recently, a wider spectrum of seizure syndromes have been associated with functional impairment of glucose transport caused by SLC2A1 mutations. These syndromes include 12% of early-onset absence epilepsy and 1% of genetic generalised epilepsies, where they represent a risk allele contributing to polygenic inheritance. We describe a young man with early-onset absence seizures and paroxysmal exercise-induced dyskinesia. While this syndrome is uncommon, it is recognisable and its diagnosis allows consideration of treatment with the ketogenic diet. We discuss the role of genetic testing in early-onset absence seizures and genetic generalised epilepsy.

A three-year-old boy with glucose transporter type 1 deficiency syndrome presenting with episodic ataxia.

INTRODUCTION: Glucose transporter type 1 deficiency syndrome is a metabolic encephalopathy that results from impaired glucose transport into the brain as the result of a mutation of the SLC2A1 gene. It has been recognized recently that these patients can present with a much broader clinical spectrum than previously thought. We describe a 3-year-old boy presenting with episodic ataxia. CASE REPORT: Our patient exhibited periodic abnormal eye movements, including opsoclonus, since he was 4 months of age. At 2 years of age, he experienced acute cerebellar ataxia after a vaccination. Since then, he has had periodic attacks of ataxic gait, repeated vomiting, and abnormal eye movement. He was diagnosed as having episodic ataxia type 2 because the administration of acetazolamide seemed effective. By 3 years and 10 months of age, he exhibited mild mental retardation and mild trunk ataxia. The attacks were more likely to occur when he was hungry. Molecular analysis revealed that the SLC2A1 gene had a de novo mutation of heterozygous seven nucleotide insertion within exon 7, resulting in a frameshift. He has recently begun a modified Atkins diet; the frequency of attacks has been reduced, and his psychomotor and language skills have begun to develop. DISCUSSION: Glucose transporter type 1 deficiency syndrome should be considered in the differential diagnosis in children with episodic ataxia, even if acetazolamide is effective.