Abstract

MONTEIRO, Tânia; MARTINS, Esmeralda  and  CHORAO, Rui. Caso electroencefalográfico. Nascer e Crescer [online]. 2011, vol.20, n.4, pp.290-293. ISSN 0872-0754.

Introduction: The suppression-burst (SB) electroen­cephalographic pattern is rather common during the neonatal period and suggests severe encephalopathy. When significant hypoxic-ischemic insult is excluded, brain malformations and metabolic disorders have to be ruled out. Two distinctive epi­leptic syndromes are described: early epileptic encephalopathy with SB (Ohtahara syndrome) and early myoclonic epilepsy (EME). The later is frequently associated with neurometabolic disorders, one of the most common being nonketotic hypergly­cinemia (NKH). Case report: A baby girl presented with multiple erratic clo­nic and myoclonic seizures from the second day of life, refrac­tory to antiepileptic drugs. She was hypotonic, lethargic and had episodes of apnea. The electroencephalogram (EEG) showed multiple bursts of multifocal epileptiform activity with long periods of almost flat tracing; this pattern persisted beyond the neonatal period, it was present at the last EEG performed at age four mon­ths. Barbiturate-induced coma with mechanical ventilation was induced. She died at the age of five months. The second but not the first sample of cerebrospinal fluid (CSF) and blood revealed an increased CSF/serum glycine ra­tio (0,11 - normal<0,03). Post-morten liver tissue biopsy found a deficit at the glycine cleavage system (GCS) (6,6 mkat/ kg - nor­mal 45,0-195,0) and molecular studies detected a mutation in the gene GLDC molecular testing. This result allowed better parent’s genetic counseling. Conclusions: Early myoclonic epilepsy presents with multi­focal seizures and SB on pattern on the EEG in the neonatal period, metabolic causes must be investigated, namely the neo­natal form of NHK. CSF and plasma aminoacids, including gly­cine levels, should be measured, simultaneously and sometimes repeatedly. Enzymatic and molecular analysis may confirm this diagnosis and are useful for parent’s genetic counseling.

Keywords : Supression-burst EEG pattern; early myoclonic epilepsy; nonketotic hyperglycinemia.

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