The controversy regarding diagnostic criteria for early myoclonic encephalopathy

Wang, Pen-Jung; Lee, Wang-Tso; Hwu, Wuh‐Liang; Young, Chainllie; Yau, Kou-Inn Tsou; Shen, Yu-Zen

doi:10.1016/s0387-7604(98)00042-4

Cited by 24 publications

(11 citation statements)

References 17 publications

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“…Every cell function involving formation of RNA or DNA is glycinedependent because of its role in purine biosynthesis. The importance of glycine in brain function is illustrated by the finding that nonketotic hyperglycinemia is associated with early myoclonic encephalopathy that may respond to vitamin B 6 (18).…”

mentioning

confidence: 99%

Kinetics of glycine oxidation by N‐bromophthalimide in the presence of sodium dodecyl sulfate

Joshi¹,

Katre²,

Singh³

2006

J Surfact & Detergents

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The kinetics of oxidation of glycine by N-bromophthalimide (NBP) were studied in the presence of an anionic surfactant, sodium dodecyl sulfate, in acidic medium at 308 K. The rate of reaction was found to have first-order dependence on [NBP] and fractional-order dependence on [glycine] and [H + ]. The addition of reduced product of the oxidant had no significant effect on the rate of reaction. Increasing [Hg(OAc) 2 ] and [Br -] increased the rate of reaction, whereas a change in ionic strength (µ) of the medium had no effect on oxidation velocity. The rate of reaction decreased with a decrease in dielectric constant of the medium. HCN was identified as the main oxidation product of the reactions. The various activation parameters have been computed. A suitable mechanism consistent with the experimental findings has been proposed. The index of cooperativity and the micelle binding constant have been calculated.Surfactants are amphipathic molecules with both hydrophobic and hydrophilic properties. When these molecules are dissolved in water they can achieve segregation of their hydrophobic portions from the solvent by self-aggregation. Aggregates of these surfactants, known as micelles, are responsible for altering the rates of organic reactions in aqueous surfactant solutions. Additions of surfactants to mixtures of chemical reactants are considered in view of the following: first, to further understand factors that influence the rates of reaction; second, to gain additional insight into the exceptional catalysis of enzymatic reactions; and third, to explore the utility of micellar systems for the purpose of synthesis. The micellar catalysis in chemical reactions is well reported (1-7). The hydrophobic and electrostatic forces in the presence of surfactants influence the rates of several redox reactions (8-17). The observed rate of reaction depends on the association between the reactants and micellar aggregates. Different models have been proposed to describe the reactions in the presence of micelles.Glycine occurs about every third amino acid in collagen, the most abundant protein in the body. It can be used directly as an energy source or for synthesis of glucose to supply blood sugar. It is required for porphyrin synthesis to initiate the pathway leading to heme formation. Every cell function involving formation of RNA or DNA is glycinedependent because of its role in purine biosynthesis. The importance of glycine in brain function is illustrated by the finding that nonketotic hyperglycinemia is associated with early myoclonic encephalopathy that may respond to vitamin B 6 (18).Previous work on the oxidation and halogenation of glycine by N-halo compounds has received considerable attention (19-28); however, very limited work on the kinetics of oxidation of glycine by N-halo compounds has been documented (29-31). A perusal of the literature shows that the reactivity of N-bromophthalimide (NBP) could be compared with that of other N-bromoimides such as N-bromosuccinimide (NBS) and N-bromosaccharin (NBSA). NB...

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mentioning

confidence: 99%

Kinetics of glycine oxidation by N‐bromophthalimide in the presence of sodium dodecyl sulfate

Joshi¹,

Katre²,

Singh³

2006

J Surfact & Detergents

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“…NKHG, propionic aciduria, and D-glyceric acidemia were reported to lead to EME, but there were still many cases with unknown causes. [4,5] In a study on 29 cases fulfilling the EME criteria, there were inborn errors of metabolism in eight, congenital brain malformations in five, and birth asphyxia in six cases. The remaining ten cases were accepted as cryptogenic.…”

Section: Discussionmentioning

confidence: 99%

Repetitive EEG recordings are necessary for the diagnosis of early myoclonic encephalopathy

et al. 2005

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Early myoclonic encephalopathy (EME) is a rare malignant epileptic syndrome. The erratic myoclonus with or without focal motor seizures, time of onset before 3 months of age, and suppression-burst (SB) pattern in EEG are accepted as the diagnostic criteria for EME. We report a 40-day-old infant with the diagnosis of non-ketotic hyperglycinemia (NKHG). The infant developed myoclonic and focal tonic seizures on the first day of life. His first sleep EEG recorded after onset of seizure was normal. Because of the diagnosis of NKHG and early developed myoclonic seizure, we thought the infant might be EME, and repeated sleep EEG on admission in which asymmetrical SB pattern was seen. We concluded that the absence of SB pattern in the first EEG recording does not exclude the diagnosis of EME, but repetition of EEG is necessary to demonstrate the presence of SB pattern to meet the diagnostic criteria for EME.

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“…Most of the cases of EIEE are associated with structural brain anomalies while the better part of EME with metabolic disorders (including nonketotic hyperglycinemia) [16,20,[30][31][32][33]. Nevertheless, the etiology of EIEE is heterogeneous, and patients with EIEE often have acquired causes (e.g., HIE), structural brain defects (e.g., cortical brain malformations), or metabolic disorders [34,35].…”

Section: Severe Early-onset Epileptic Encephalopathy (Eoees) With a Smentioning

confidence: 99%

GABAergic Interneurons in Severe Early Epileptic Encephalopathy with a Suppression-Burst Pattern: A Continuum of Pathology

Carrascosa-Romero¹,

Cabo²

2016

Epileptology - The Modern State of Science

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Early infantile epileptic encephalopathy (EIEE) and early myoclonic encephalopathy (EME) are catastrophic epilepsies starting in the neonatal period. The International League Against Epilepsy classifies both of them as generalized symptomatic epilepsies of nonspecific etiology, characterized by early onset, presence of burst-suppression EEG pattern and serious prognosis. The critical difference lies in their presumed etiologies and the prevailing clinical seizure type at onset: EIEE (known as Ohtahara syndrome) usually manifests with tonic seizures, while EME is mainly associated with myoclonic seizures. However, the distinction between those two pathologies is not always easy due to clinical and etiological overlap. Both mutations in the ARX gene for EIEE (OMIM 308350) and disruption in the neuregulin receptor ErbB4 for EME (OMIM 609304) impair interneuron migration and alter the number of GABAergic interneurons in the postnatal cortex. These findings could explain the occurrence of severe epileptic encephalopathy with a burst-suppression pattern and represent a continuum of progressive pathology. In the present chapter we review the genes involved in EIEE and EME including their possible mechanisms of action, particularly via GABAegic interneurons. Their clinical manifestations are myoclonic or tonic seizures, which represent the expression of the underlying pathology and correlate with degree of brain damage.

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The controversy regarding diagnostic criteria for early myoclonic encephalopathy

Cited by 24 publications

References 17 publications

Kinetics of glycine oxidation by N‐bromophthalimide in the presence of sodium dodecyl sulfate

Kinetics of glycine oxidation by N‐bromophthalimide in the presence of sodium dodecyl sulfate

Repetitive EEG recordings are necessary for the diagnosis of early myoclonic encephalopathy

GABAergic Interneurons in Severe Early Epileptic Encephalopathy with a Suppression-Burst Pattern: A Continuum of Pathology

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