ABSTRACT
Early myoclonic encephalopathy (EME) is a rare malignant epileptic syndrome. The erratic myoclonus with or without focal motor seizures, onset before 3 months of age, and persistent suppression-burst pattern in electroencephalograph (EEG) are accepted as the diagnostic criteria for EME. We report an 11 month-old infant with EME which was secondary to non-ketotic hyperglycinemia.
Subject(s)
Anticonvulsants/therapeutic use , Electroencephalography/methods , Epilepsies, Myoclonic/diagnosis , Epilepsies, Myoclonic/drug therapy , Epilepsies, Myoclonic/etiology , Humans , Hyperglycinemia, Nonketotic/complications , Hyperglycinemia, Nonketotic/diagnosis , Infant , MaleABSTRACT
Nonketotic hyperglycinemia has variable phenotypic expressions and a poor prognosis. We report a case of severe neonatal nonketotic hyperglycinemia, who started convulsing immediately after birth. His glycine index was 0.38 and he did not respond to treatment with sodium benzoate and dextromethorphan. Hypotonia, transient hyperammonemia and metabolic acidosis were associated findings.
Subject(s)
Amino Acid Metabolism, Inborn Errors/diagnosis , Disease Progression , Fatal Outcome , Glycine/metabolism , Humans , Hyperglycinemia, Nonketotic/diagnosis , Infant, Newborn , Male , Rare Diseases , Risk Assessment , Seizures/diagnosisABSTRACT
Seizures are a common problem in neonates. Differential diagnoses include infection, trauma, hypoxia and congenital metabolic disorders. Among these, congenital metabolic disorder is less familiar to general pediatricians. We report two patients with nonketotic hyperglycinemia (NKH), a rare and lethal congenital metabolic disease. Transient hyperammonemia and transient hypouricemia, uncommon features found in NKH, were detected in one patient. High doses of sodium benzoate and dextromethorphan failed to modify the clinical course. Neuropathology denoted characteristic diffuse vacuolization and changes in reactive and gliotic astrocytes. The clinical course, biochemical findings, diagnostic approaches and diagnostic tests are discussed in detail. Recent modalities of treatment are reviewed. Because of its rarity and rapidly progressive course, it maybe underdiagnosed resulting in death before being recognized. Awareness of the possibility of congenital metabolic disorder in early neonatal catastrophe will increase the diagnostic rate.
Subject(s)
Diagnosis, Differential , Fatal Outcome , Humans , Hyperglycinemia, Nonketotic/diagnosis , Infant, Newborn , Infant, Newborn, Diseases/diagnosis , Male , Seizures/etiologyABSTRACT
Nonketotic hyperglycinemia (NKH) is a rare metabolic brain disease caused by deficient activity of the glycine cleveage system. Localized proton MR spectroscopy (echo-time 166 msec), performed in an infant with the typical clinical and biochemical features of neonatal NKH, showed a markedly increased peak intensity at 3.55 ppm, which was assigned to glycine. Serial proton MR spectrosocpic studies indicated that glycine/choline and glycine/total creatine ratios correlated closely with the patient's clinical course. Proton MR spectroscopy was useful for the non-invasive detection and monitoring of cerebral glycine levels in this infant with NKH.