Electroacupuncture Attenuated Anxiety and Depression-Like Behavior via Inhibition of Hippocampal Inflammatory Response and Metabolic Disorders in TNBS-Induced IBD Rats.

This study was designed to explore the potential mechanisms of electroacupuncture (EA) in treating inflammatory bowel disease- (IBD-) related anxiety and mood disorders. A colitis model was induced in rats with 2, 4, 6-trinitrohydrosulfonic acid (TNBS), followed by ST36 and SP6 targeted therapy by EA or sham EA treatment. The elevated plus maze (EPM) and open-field test (OFT) were performed to assess the state of anxiety and depression-like behavior. Tests were carried out by 16S rDNA amplification sequence, 1H nuclear magnetic resonance (1H NMR) spectroscopy, immunofluorescence staining, and enzyme-linked immunosorbent assay (ELISA). The analyses detailed metabolic alterations and the Toll-like receptor 4 (TLR4) signaling pathway/NOD-like receptor protein 3 (NLRP3) inflammasome in rats' hippocampal region. Furthermore, the activity of the hypothalamic-pituitary adrenal (HPA) axis and gut microbiome was assessed. As a result of treatment, EA significantly improved in the behavioral tests and altered the composition of the gut microbiome through a significant increase in the density of short chain fatty acids (SCFAs) producers mainly including Ruminococcaceae, Phascolarctobacterium, and Akkermansiaceae. EA upregulated the metabolites of the hippocampus mainly containing l-glutamine and gamma-aminobutyric acid (GABA), as well as ZO-1 expression. Whereas the treatment blocked the TLR4/nuclear factor- kappa B (NF-κB) signaling pathways and NLRP3 inflammasomes, along with downregulating the interleukin- (IL-) 1ß level. The hyperactivity of the HPA axis was also diminished. In conclusion, EA at ST36 and SP6 attenuated anxiety and depression-like behavior in colitis model rats through their effects on the gut microbiome by modulating the hippocampal inflammatory response and metabolic disorders, as well as the HPA axis. This study provides evidence for clinical application of EA to serve as an adjunctive treatment for IBD-related anxiety and depression.

Symptom Prevalence and Genotype-Phenotype Correlations in Patients With TANGO2-Related Metabolic Encephalopathy and Arrhythmias (TRMEA).

BACKGROUND: TANGO2-related metabolic encephalopathy and arrhythmias (TRMEA) is a rare, phenotypically heterogeneous, neurological disease affecting children. METHODS: We conducted a chart review of five children with molecularly confirmed TRMEA diagnosed at our institution and compiled pathogenic variant frequency and symptom prevalence from cases previously reported in the literature. RESULTS: Including those patients in our case series, 76 patients with TRMEA have been described. Developmental delay (93%) and/or regression (71%), spasticity (78%), and seizures (57%) are common in TRMEA and frequently precede life-threatening symptoms such as metabolic decompensation with lactic acidosis (83%), cardiomyopathy (38%), and cardiac arrhythmias (68%). Deletion of exons 3 to 9 is the most common pathogenic variant (39% of alleles). The majority of reported intragenic variants (17 of 27) result in disruption of the reading frame, and no clear genotype-phenotype correlations could be identified for those variants wherein the reading frame is maintained, highlighting instead the variable expressivity of the disease. CONCLUSIONS: Patients with TRMEA frequently experience life-threatening complications that are preceded by common neurological symptoms underscoring the need for pediatric neurologists to be familiar with this condition. Additional work pertaining to disease pathophysiology and potential therapeutics is needed.

Phenotypic and molecular spectrum of pyridoxamine-5'-phosphate oxidase deficiency: A scoping review of 87 cases of pyridoxamine-5'-phosphate oxidase deficiency.

Pyridoxamine-5'-phosphate oxidase (PNPO) deficiency is an autosomal recessive pyridoxal 5'-phosphate (PLP)-vitamin-responsive epileptic encephalopathy. The emerging feature of PNPO deficiency is the occurrence of refractory seizures in the first year of life. Pre-maturity and fetal distress, combined with neonatal seizures, are other associated key characteristics. The phenotype results from a dependency of PLP which regulates several enzymes in the body. We present the phenotypic and genotypic spectrum of (PNPO) deficiency based on a literature review (2002-2020) of reports (n = 33) of patients with confirmed PNPO deficiency (n = 87). All patients who received PLP (n = 36) showed a clinical response, with a complete dramatic PLP response with seizure cessation observed in 61% of patients. In spite of effective seizure control with PLP, approximately 56% of patients affected with PLP-dependent epilepsy suffer developmental delay/intellectual disability. There is no diagnostic biomarker, and molecular testing required for diagnosis. However, we noted that cerebrospinal fluid (CSF) PLP was low in 81%, CSF glycine was high in 80% and urinary vanillactic acid was high in 91% of the cases. We observed only a weak correlation between the severity of PNPO protein disruption and disease outcomes, indicating the importance of other factors, including seizure onset and time of therapy initiation. We found that pre-maturity, the delay in initiation of PLP therapy and early onset of seizures correlate with a poor neurocognitive outcome. Given the amenability of PNPO to PLP therapy for seizure control, early diagnosis is essential.

Phenotypic spectrum of short-chain enoyl-Coa hydratase-1 (ECHS1) deficiency.

INTRODUCTION: ECHS1 encodes for short-chain enoyl-CoA hydratase, a key component in b-oxidation. This enzyme is also involved in the isoleucine and valine catabolic pathways. The literature contains reports of scattered cases of ECHS1 mutation, which show a wide clinical spectrum of presentation. Despite that the clinical spectrum of the disease has not been defined so far due to the absence of previous systematic reviews and descriptions of large series of patients. METHODS: We performed a systematic literature review of so far reported ECHS1 mutated patients and we reported two additional cases. We pointed out clinical and neuroradiological features of all patients. RESULTS: 45 patients were included in the analysis. Based on clinical and neuroradiological feature we were able to distinguish four main phenotypes of ECHS1deficiency: a severe neonatal presentation with a rapid and fatal course and significant white matter abnormalities; a severe infantile variant with slower neurological deterioration, developmental delay, pyramidal and extrapyramidal signs, optic atrophy, feeding difficulties, and degeneration of the deep gray nuclei; a slowly progressive infantile form, qualitatively similar to the previous phenotype, but less severe with mainly basal ganglia involvement; and a final phenotype, present in only few cases, characterized by paroxysmal exercise-induced dystonic attacks, normal neurological examination between these episodes, and isolated pallidal degeneration on MRI. INTERPRETATION: ECHS1 mutations cause metabolic encephalopathy with a wide range of clinical presentations that can be grouped into four main phenotypes, each with a distinct profile in terms of severity on clinical presentation, disease course and MRI involvement.

Encephalopathy in cystic fibrosis.

Cystic fibrosis liver disease (CFLD) affects a large proportion of cystic fibrosis (CF) patients; however encephalopathy is a rare complication. While classical hepatic encephalopathy can be a feature of end-stage liver disease, "hyperammonemic encephalopathy" can be precipitated in previously stable CFLD by various triggers including systemic corticosteroids. We describe one such case and review the relevant literature.

Neuroimaging Spectrum of Inherited Neurotransmitter Disorders.

Inherited neurotransmitter disorders are rare neurometabolic conditions which encompass genetic disorders of neurotransmitter metabolism or transport. The clinical manifestations of these rare disorders are often nonspecific, ranging from encephalopathies and seizures to movement disorders. As a consequence, neurotransmitter disorders are underrecognized and often misdiagnosed. Accurate and timely diagnosis is, however, of utmost importance, given the availability of therapeutic strategies. A high index of clinical suspicion and familiarity with the neuroimaging phenotypes is therefore crucial. While the imaging features of various neurotransmitter disorders often overlap and are nonspecific, imaging can be helpful in providing useful clues to guide the diagnostic algorithm for uncommon conditions in a neonate presenting with nonspecific neurological symptoms. In this review paper, we aim to bring together current knowledge of neuroimaging phenotypes associated with inherited (primary) disorders of neurotransmitter biosynthesis. Magnetic resonance imaging phenotypes of disorders of monoamine biosynthesis, primary cerebral folate deficiency, disorders of pyridoxine metabolism, disorders of gamma-aminobutyric acid metabolism, nonketotic hyperglycinemia (glycine encephalopathy), disorders of serine biosynthesis, and cerebral creatine deficiency syndrome will be discussed and illustrated with case examples.

Stress-Induced Metabolic Disorder in Peripheral CD4+ T Cells Leads to Anxiety-like Behavior.

Physical or mental stress leads to neuroplasticity in the brain and increases the risk of depression and anxiety. Stress exposure causes the dysfunction of peripheral T lymphocytes. However, the pathological role and underlying regulatory mechanism of peripheral T lymphocytes in mood disorders have not been well established. Here, we show that the lack of CD4+ T cells protects mice from stress-induced anxiety-like behavior. Physical stress-induced leukotriene B4 triggers severe mitochondrial fission in CD4+ T cells, which further leads to a variety of behavioral abnormalities including anxiety, depression, and social disorders. Metabolomic profiles and single-cell transcriptome reveal that CD4+ T cell-derived xanthine acts on oligodendrocytes in the left amygdala via adenosine receptor A1. Mitochondrial fission promotes the de novo synthesis of purine via interferon regulatory factor 1 accumulation in CD4+ T cells. Our study implicates a critical link between a purine metabolic disorder in CD4+ T cells and stress-driven anxiety-like behavior.

Baclofen Neurotoxicity: A Metabolic Encephalopathy Susceptible to Exacerbation by Benzodiazepine Therapy.

PURPOSE: Baclofen has been reported to cause both a metabolic encephalopathy and nonconvulsive status epilepticus. Baclofen is typically used in the management of muscle spasticity but is being increasingly used to manage alcohol withdrawal and opiate dependency. Given the increasing use of baclofen we describe the clinical and electrographical features of baclofen neurotoxicity seen at our institution. METHODS: The clinical and EEG features of patients with an encephalopathy in the setting of baclofen therapy were analyzed. Patients were identified via our hospital EEG database. RESULTS: Fourteen patients were identified having presented with an acute confusional state without identifiable cause other than baclofen use. Five patients took a deliberate overdose, three of whom were baclofen naive, two patients presented after medication prescription error, and seven patients were on stable doses (30-140 mg daily). All patients presented with an encephalopathy, one patient was reported to have clinical seizures, and seven had multifocal myoclonus. EEGs were abnormal in all patients and showed moderate to severe generalized slowing. Generalized triphasic waves occurring at 1 to 2 Hz, sometimes with an anterior to posterior phase lag, were present in 10 patients (71%), and intermittent generalized suppression of the background was seen in three patients. Three patients received small doses of intravenous benzodiazepines, resulting in a marked depression of consciousness and respiration. All patients recovered within 48 hours of baclofen discontinuation. CONCLUSIONS: Baclofen toxicity can produce an acute encephalopathy even at modest doses, with the EEG showing generalized slowing and triphasic waves consistent with a toxic encephalopathy. Management consists of supportive care and cessation of baclofen. Patients with baclofen neurotoxicity exhibit a marked vulnerability to the depressant effects of benzodiazepines.

Movement Disorders in Treatable Inborn Errors of Metabolism.

There are several hundred single-gene disorders that we classify as inborn errors of metabolism. Inborn errors of metabolism are often rare and highly heterogeneous multisystem diseases with non-neurological and neurological manifestations, commonly with onset during childhood. Movement disorders are among the most common neurological problems in inborn errors of metabolism, but, in many cases, remain poorly defined. Although movement disorders are usually not the only and often not the presenting symptom, their recognition can facilitate a diagnosis. Movement disorders contribute substantially to the morbidity in inborn errors of metabolism and can have a significant impact on quality of life. Common metabolic movement disorders include the monoamine neurotransmitter disorders, disorders of amino and organic acid metabolism, metal storage disorders, lysosomal storage disorders, congenital disorders of autophagy, disorders of creatine metabolism, vitamin-responsive disorders, and disorders of energy metabolism. Importantly, disease-modifying therapies exist for a number of inborn errors of metabolism, and early recognition and treatment can prevent irreversible CNS damage and reduce morbidity and mortality. A phenomenology-based approach, based on the predominant movement disorder, can facilitate a differential diagnosis and can guide biochemical, molecular, and imaging testing. The complexity of metabolic movement disorders demands an interdisciplinary approach and close collaboration of pediatric neurologists, neurologists, geneticists, and experts in metabolism. In this review, we develop a general framework for a phenomenology-based approach to movement disorders in inborn errors of metabolism and discuss an approach to identifying the "top ten" of treatable inborn errors of metabolism that present with movement disorders-diagnoses that should never be missed. © 2018 International Parkinson and Movement Disorder Society.

Malignant brain tumors in patients with glutaric aciduria type I.

Three young patients with glutaric aciduria type I (age 6-23 years) of different ethnic origins, treated for their metabolic disease since early childhood, presented with malignant central nervous system tumors. We recommend continuing clinical follow-up, including monitoring of neurological manifestations and neuroradiological findings, in all patients with glutaric aciduria type I beyond early childhood, especially if adherence to diet is poor or the treatment was not started neonatally.

Treatment, Therapy and Management of Metabolic Epilepsy: A Systematic Review.

Metabolic epilepsy is a metabolic abnormality which is associated with an increased risk of epilepsy development in affected individuals. Commonly used antiepileptic drugs are typically ineffective against metabolic epilepsy as they do not address its root cause. Presently, there is no review available which summarizes all the treatment options for metabolic epilepsy. Thus, we systematically reviewed literature which reported on the treatment, therapy and management of metabolic epilepsy from four databases, namely PubMed, Springer, Scopus and ScienceDirect. After applying our inclusion and exclusion criteria as per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we reviewed a total of 43 articles. Based on the reviewed articles, we summarized the methods used for the treatment, therapy and management of metabolic epilepsy. These methods were tailored to address the root causes of the metabolic disturbances rather than targeting the epilepsy phenotype alone. Diet modification and dietary supplementation, alone or in combination with antiepileptic drugs, are used in tackling the different types of metabolic epilepsy. Identification, treatment, therapy and management of the underlying metabolic derangements can improve behavior, cognitive function and reduce seizure frequency and/or severity in patients.

Metabolic Encephalopathy: Behind the Name.

Metabolic encephalopathy may be the most common diagnosis in consultative acute neurology. The origin of this term is not generally known but can be traced back. The term replaced more commonly used designations such as organic or functional. The term metabolic encephalopathy was originally linked to organ dysfunction but subsequently became more imprecise. When it expanded to include a large number of diseases, it evolved to "metabolic neuronal dysfunction" and soon could not be distinguished from "quiet delirium" and other designations. This vignette summarizes why the terminology has confused more than clarified but also why it will likely stay in the neurologist's vernacular.

Pyridoxine-5'-phosphate oxidase (Pnpo) deficiency: Clinical and biochemical alterations associated with the C.347g>A (P.·Arg116gln) mutation.

BACKGROUND: Pyridoxal-5'-phosphate oxidase (PNPO) deficiency presents as a severe neonatal encephalopathy responsive to pyridoxal-5'-phosphate (PLP) or pyridoxine. Recent studies widened the phenotype of this condition and detected genetic variants on PNPO gene whose pathogenic role and clinical expression remain to be established. OBJECTIVE: This paper aims to characterize the functional effects of the c.347G>A (p.Arg116Gln) mutation in the PNPO gene in order to define its pathogenicity and describe the clinical features of new patients with epilepsy carrying this mutation. METHODS: Arg116Gln protein variant was expressed as recombinant protein. The mutant protein was characterized with respect to structural and kinetic properties, thermal stability, binding constants of cofactor (FMN) and product (PLP). We also reviewed clinical data of 3 new patients carrying the mutation. RESULTS: The Arg116Gln mutation does not alter the overall enzyme structure and only slightly affects its catalytic efficiency; nevertheless, this mutation affects thermal stability of PNPO, reduces its affinity for FMN and impairs transfer of PLP to PLP-dependent enzymes. Three boys with seizure onset between 8months and 3years of age, carrying the Arg116Gln mutation, are described. These three patients exhibited different seizure types associated with interictal EEG abnormalities and slow background activity. Mild/moderate intellectual disability was observed in 2/3 patients. A dramatic therapeutic response to pyridoxine was observed in the only patient who still had active seizures when starting treatment, while in all three patients interictal EEG discharges and background activity improved after pyridoxine treatment was initiated. CONCLUSIONS: The reported data support a pathogenic role of the c.347G>A (p.Arg116Gln) mutation in PNPO deficiency. The later onset of symptoms and the milder epilepsy phenotype of these expand the disease phenotype.

Clinical awareness for health care professionals: Fatal encephalopathy complicating persistent vomiting in pregnancy.

Women with persistent vomiting during pregnancy need early referral to appropriate health facilities. Delayed referral and inappropriate management may lead to metabolic encephalopathy from a variety of causes, including electrolyte derangements or thiamine deficiency (Wernicke's encephalopathy) (WE). We present a case of persistent vomiting in pregnancy in which there was delayed referral, inappropriate treatment and failure to associate neurological signs such as terminal neck stiffness with WE, resulting in poor fetomaternal outcomes. In this report, we discuss the following lessons: (i) the need for early transfer of a patient with persistent vomiting and enigmatic clinical features to a higher healthcare facility; (ii) failure to associate neurological signs with complications of hyperemesis gravidarum/WE; (iii) lack of thiamine supplementation; and (iv) the advantages of magnetic resonance imaging over a computed tomography scan in the diagnosis of WE.

The M405V allele of the glutaryl-CoA dehydrogenase gene is an important marker for glutaric aciduria type I (GA-I) low excretors.

Glutaric aciduria type I (GA-I) is an autosomal recessive organic aciduria resulting from a functional deficiency of glutaryl-CoA dehydrogenase, encoded by GCDH. Two clinically indistinguishable diagnostic subgroups of GA-I are known; low and high excretors (LEs and HEs, respectively). Early medical and dietary interventions can result in significantly better outcomes and improved quality of life for patients with GA-I. We report on nine cases of GA-I LE patients all sharing the M405V allele with two cases missed by newborn screening (NBS) using tandem mass spectrometry (MS/MS). We describe a novel case with the known pathogenic M405V variant and a novel V133L variant, and present updated and previously unreported clinical, biochemical, functional and molecular data on eight other patients all sharing the M405V allele. Three of the nine patients are of African American ancestry, with two as siblings. GCDH activity was assayed in six of the nine patients and varied from 4 to 25% of the control mean. We support the use of urine glutarylcarnitine as a biochemical marker of GA-I by demonstrating that glutarylcarnitine is efficiently cleared by the kidney (50-90%) and that plasma and urine glutarylcarnitine follow a linear relationship. We report the allele frequencies for three known GA-I LE GCDH variants (M405V, V400M and R227P) and note that both the M405V and V400M variants are significantly more common in the population of African ancestry compared to the general population. This report highlights the M405V allele as another important molecular marker in patients with the GA-I LE phenotype. Therefore, the incorporation into newborn screening of molecular screening for the M405V and V400M variants in conjunction with MS/MS could help identify asymptomatic at-risk GA-I LE patients that could potentially be missed by current NBS programs.

Acidosis-Induced Dysfunction of Cortical GABAergic Neurons through Astrocyte-Related Excitotoxicity.

BACKGROUND: Acidosis impairs cognitions and behaviors presumably by acidification-induced changes in neuronal metabolism. Cortical GABAergic neurons are vulnerable to pathological factors and their injury leads to brain dysfunction. How acidosis induces GABAergic neuron injury remains elusive. As the glia cells and neurons interact each other, we intend to examine the role of the astrocytes in acidosis-induced GABAergic neuron injury. RESULTS: Experiments were done at GABAergic cells and astrocytes in mouse cortical slices. To identify astrocytic involvement in acidosis-induced impairment, we induced the acidification in single GABAergic neuron by infusing proton intracellularly or in both neurons and astrocytes by using proton extracellularly. Compared the effects of intracellular acidification and extracellular acidification on GABAergic neurons, we found that their active intrinsic properties and synaptic outputs appeared more severely impaired in extracellular acidosis than intracellular acidosis. Meanwhile, extracellular acidosis deteriorated glutamate transporter currents on the astrocytes and upregulated excitatory synaptic transmission on the GABAergic neurons. Moreover, the antagonists of glutamate NMDA-/AMPA-receptors partially reverse extracellular acidosis-induced injury in the GABAergic neurons. CONCLUSION: Our studies suggest that acidosis leads to the dysfunction of cortical GABAergic neurons by astrocyte-mediated excitotoxicity, in addition to their metabolic changes as indicated previously.