Ketogenic diet as a glycine lowering therapy in nonketotic hyperglycinemia and impact on brain glycine levels.

BACKGROUND: Nonketotic hyperglycinemia (NKH) is a severe neurometabolic disorder characterized by increased glycine levels. Current glycine reduction therapy uses high doses of sodium benzoate. The ketogenic diet (KD) may represent an alternative method of glycine reduction. AIM: We aimed to assess clinical and biochemical effects of two glycine reduction strategies: high dose benzoate versus KD with low dose benzoate. METHODS: Six infants with NKH were first treated with high dose benzoate therapy to achieve target plasma glycine levels, and then switched to KD with low dose benzoate. They were evaluated as clinically indicated by physical examination, electroencephalogram, plasma and cerebral spinal fluid amino acid levels. Brain glycine levels were monitored by magnetic resonance spectroscopy (MRS). RESULTS: Average plasma glycine levels were significantly lower with KD compared to benzoate monotherapy by on average 28%. Two infants underwent comparative assessments of brain glycine levels via serial MRS. A 30% reduction of brain glycine levels was observed in the basal ganglia and a 50% reduction in the white matter, which remained elevated above normal, and was equivalent between the KD and high dose benzoate therapies. CSF analysis obtained while participants remained on the KD showed a decrease in glycine, serine and threonine levels, reflecting their gluconeogenetic usage. Clinically, half the patients had seizure reduction on KD, otherwise the clinical impact was variable. CONCLUSION: KD is an effective glycine reduction method in NKH, and may provide a more consistent reduction in plasma glycine levels than high-dose benzoate therapy. Both high-dose benzoate therapy and KD equally reduced but did not normalize brain glycine levels even in the setting of low-normal plasma glycine.

A Multicenter Study of Adherence to Best Practices and Application of Epilepsy Quality Metrics in a Pediatric Telemedicine Encounter.

Objective: To assess Epilepsy Quality Metrics (EQM) and guideline implementation in new pediatric patients seen in telemedicine. Methods: Multicenter, cross sectional, retrospective analysis. Results: Patients were similar across 3 centers for age, gender, and insurance type. Eighty-one percent presented for spells. One hundred sixty patients with epilepsy formed the EQM cohort. Results: Seizures described: 95%; frequency: 67%, last seizure documented: 81%, epilepsy syndrome documented: 67%; epilepsy diagnosis: 77%, medications reviewed: 56%, adverse events discussed: 73%. Quality of life discussed: 3%. Anticipatory guidance was described as follows: seizure safety, 57%; driving, 47%; SUDEP, 11%; vitamin D discussion, 19%; pregnancy and folic acid counseling, 4% and 10%. Epileptologists were 4 times as likely as generalists in discussing driving safety (odds ratio 3.93, 95% confidence interval 1.7-8.9; P = .001) for all ages. Significance: Performance on EQM and guideline implementation in pediatric epilepsy telemedicine encounters can be improved.

Semiautomated Spike Detection Software Persyst 13 Is Noninferior to Human Readers When Calculating the Spike-Wave Index in Electrical Status Epilepticus in Sleep.

PURPOSE: Our objective was to use semiautomatic methods for calculating the spike-wave index (SWI) in electrical status epilepticus in slow-wave sleep (ESES) and to determine whether this calculation is noninferior to human experts (HEs). METHODS: Each HE marked identical 300-second epochs for all spikes and calculated the SWI in sleep EEGs of patients diagnosed with ESES. Persyst 13 was used to mark spikes (high sensitivity setting) in the same 300-second epochs marked by HEs. The spike-wave index was calculated. Pairwise HE differences and pairwise Persyst 13 (P13)-HE differences for the SWI were calculated. Bootstrap resampling (BCa, N = 3,000) was performed to better estimate mean differences and their 95% confidence bounds between HE and P13-HE pairs. Potential noninferiority of P13 to HEs was tested by comparing the 95% confidence bounds of the mean differences between pairs for the SWI. RESULTS: Twenty EEG records were analyzed. Each HE marked 100 minutes of EEG. HEs 1, 2, 3, and 4 marked 10,075, 8,635, 9,710, and 9,898 spikes, respectively. The highest and lowest 95% confidence bound of the mean difference in the SWI between HE pairs was: High: 10.3%; Low: -10.2%. Highest and lowest 95% confidence bound of the mean difference in the SWI between P13 and HE pairings was as follows: high, 9.5% and low, -6.7%. The lack of a difference between P13 and HEs supports that the algorithm is not inferior to HEs. CONCLUSIONS: Persyst 13 is noninferior to HEs in calculating the SWI in ESES, thus suggesting that an automated approach to SWI calculation may be a useful clinical tool.

Management of Status Epilepticus in Children.

Status epilepticus is a common pediatric neurological emergency. Management includes prompt administration of appropriately selected anti-seizure medications, identification and treatment of seizure precipitant(s), as well as identification and management of associated systemic complications. This review discusses the definitions, classification, epidemiology and management of status epilepticus and refractory status epilepticus in children.

Generalized epilepsies: immunologic and inflammatory mechanisms.

This article focuses on the inflammatory processes in patients with generalized epilepsies. We specifically review the data regarding West, Lennox-Gastaut, and Landau-Kleffner syndromes as they have generalized clinical or electroencephalogram features. There is substantial evidence for a pathogenic implication of immune mechanisms in these epilepsies. Animal models and abnormalities in both cellular and humoral immunity support this hypothesis. They also appear to be particularly responsive to immunomodulatory therapies, which has raised the speculation that an unbalanced immune system may play an important role in the pathophysiology of these epileptic syndromes. In this article, we discuss clinical and experimental data that support the potential implication of immune mediated inflammation and immune response in the mechanism of these entities.

Fraternal twins with autism, severe cognitive deficit, and epilepsy: diagnostic role of chromosomal microarray analysis.

A 7-year-old child presented with atypical absence epilepsy. He also had autism and severe cognitive deficit. As part of his diagnostic workup, a chromosomal microarray analysis was performed, which showed novel biallelic deletions in the neurexin 1 gene (NRXN1). His fraternal twin sister, who also had autism and cognitive impairment, was subsequently found to have the same biallelic deletions. Deletions included a 272-282kb loss at band 2p16.3 in one allele and a smaller 135-174-kb loss on the second allele. Neurexin 1 (NRXN1) is a cell adhesion protein, forming a synaptic complex with neuroligin. This signals a pathway that is critical for activity-dependent synaptic transmission. Mutations in this gene have been associated with autism and neurodevelopmental delay. Although there are many reports of heterozygous mutations with variable expressivity, only 3 cases with biallelic NRXN1 mutations have been previously reported, all of which have a more severe phenotype. We report 2 siblings with biallelic deletions, both of which affect the promoter region and exons 1-5 in the α-NRXN1 isoform, which has a role in the Ca(2+)-dependent release of neurotransmitters in the central nervous system. Our cases expand the phenotype of biallelic α NRXN 1 mutations and emphasize the important role of NRXN1 in autism and intellectual disability. Chromosomal microarray analysis should be the clinical standard in all specialties for first-tier genetic testing in autistic spectrum disorders.

Childhood primary angiitis of the central nervous system with metachronous hemorrhagic infarcts: a postmortem study with clinicopathologic correlation.

This neuropathologic case study illustrates the discovery of metachronous hemorrhagic infarcts insinuating round mass-like lesions by magnetic resonance imaging in the setting of childhood primary angiitis of the central nervous system (cPACNS) raising diagnostic awareness of this unusual presentation in a clinical and neuroimaging context. The report underscores the importance of recurrent vasculitis-induced ischemic brain damage as a pathologic correlate of relapsing cPACNS and offers a critical reappraisal of common imitators as well as a clinicopathologic approach to differential diagnosis. Attention is drawn to the caveat that although magnetic resonance imaging findings at initial presentation may not be typical for stroke, they later exhibit attributes of cerebral infarction at both the subacute and chronic stages. A pattern of cPACNS characterized predominantly by multiple petechial-like cortical hemorrhages with pathologic features of hemorrhagic infarcts is recognized. The present study lends credence to the practice of a rigorous autopsy-based approach aimed at a better understanding of the anatomic pathology and biology of cPACNS and at facilitating prospective neuroimaging and biopsy-based surgical pathology correlations, ultimately enhancing diagnostic accuracy in clinical settings. Although PACNS is, by definition, a diagnosis of exclusion, it should be considered from the outset in the differential diagnosis of ischemic stroke or hemorrhagic stroke or of unusual and relapsing intra-axial mass-like CNS lesions in children, necessitating appropriate pathologic evaluation of brain biopsy specimens.

Ring chromosome 20: a pediatric potassium channelopathy responsive to treatment with ezogabine.

BACKGROUND: Ring chromosome 20 is a genetic disorder characterized by intractable epilepsy, behavioral problems, and cognitive deficit. The potassium channel-coding gene KCNQ2 is localized at the locus q13.3 on the chromosome 20, the most common site where the ring occurs. Ezogabine is the first potassium channel opener marketed in the United States. PATIENTS: We describe an 8-year-old girl with mosaic ring chromosome 20 and refractory epilepsy who had a remarkable improvement in seizure control with ezogabine. CONCLUSIONS: This is the first report using the new antiepileptic drug ezogabine to treat pediatric epilepsy. We hypothesize that ring chromosome 20 patients have epilepsy related to abnormalities in the potassium channels, making it susceptible for treatment with potassium channel openers.

Brain natriuretic peptide is elevated in outpatients with atrial fibrillation.

Brain natriuretic peptide (BNP) levels were measured in 72 outpatients with chronic atrial fibrillation (AF) and in 49 control patients without AF. BNP levels were significantly higher in patients with AF (median value 131 pg/ml) than without AF (median value 49 pg/ml; p <0.001), and remained significantly higher after controlling for demographic and clinical variables.