[Methylmalonic aciduria associated with myoclonic convulsions, psychomotor retardation and hypsarrhythmia]. / Aciduria metilmalónica asociada a convulsiones mioclónicas, retraso psicomotor e hipsarritmia.

INTRODUCTION: Organic acidurias have long been known to cause neurological problems, such as convulsions, stupor, coma, and psychomotor and mental retardation. The organic acidurias include propionic aciduria, methylmalonic aciduria (MMA), isovaleric acidemia, lactic acidemia and glutaric acidemia type I. However, the association of MMA with electrical activity of the brain characterised by a hypsarrhythmic pattern, refractory convulsions and psychomotor retardation is very rare. CASE REPORTS: Two patients, one male and one female, were seen to have psychomotor retardation, erratic attacks of myoclonic convulsions, hypsarrhythmic encephalographic pattern and an increase in the urinary excretion of methylmalonic acid, as shown by gas chromatography and mass spectrometry, all of which supported a diagnosis of MMA in both cases. In one patient, the brain MRI with gadolinium showed lesions compatible with brain atrophy. Protein restrictions, the administration of vitamin B12 and l carnitine re established the normal neurological state and reduced the urinary excretion of methylmalonic acid in one of them. CONCLUSIONS: To the best of our knowledge these are the first cases of MMA that have been seen accompanied by hypsarrhythmia. The rareness of this clinical presentation with the characteristics described above make us suspect that we are dealing with a new clinical syndrome.

Aciduria metilmalónica asociada a convulsiones mioclónicas, retraso psicomotor e hipsarritmia / Methylmalonic aciduria associated with myoclonic convulsions, psychomotor retardation an hypsarrhythmia

Introducción. Desde hace muchos años se sabe que las acidurias orgánicas son causantes de problemas neurológicos,como convulsiones, estupor, coma y retraso psicomotor y mental. Dentro de las acidurias orgánicas se encuentran la aciduria propiónica, la aciduria metilmalónica (AMM), la acidemia isovalérica, la acidemia láctica y la acidemia glutárica tipo I. Sin embargo, la asociación de la AMM con una actividad eléctrica cerebral caracterizada por un patrón hipsarrítmico, convulsiones de difícil control terapeútico y retraso psicomotor, es muy rara. Casos clínicos. La observación de dos pacientes, uno masculino y otro femenino, con retraso psicomotor, crisis convulsivas mioclónicas erráticas, patrón encefalográfico hipsarrítmico, y la demostración por medio de la cromatografía de gases y espectrometría de masas de un aumento de la excreción urinaria de ácido metilmalónico, sustentan el diagnóstico de AMM en ambos casos. En un paciente, la RM cerebral con gadolinio mostraba lesiones compatibles con atrofia cerebral. La restricción proteica y la administración de vitamina B12 y L-carnitina devolvieron la normalidad neurológica y redujeron la excreción urinaria de ácido metilmalónico en uno de ellos. Conclusiones. Hasta donde sabemos, estos son los primeros casos de AMM que se acompañan de hipsarritmia. La rareza de esta presentación clínica con las características descritas nos hace sospechar que estamos ante un nuevo síndrome clínico (AU)

Introduction. Organic acidurias have long been known to cause neurological problems, such as convulsions, stupor, coma, and psychomotor and mental retardation. The organic acidurias include propionic aciduria, methylmalonic aciduria (MMA), isovaleric acidemia, lactic acidemia and glutaric acidemia type I. However, the association of MMA with electrical activity of the brain characterised by a hypsarrhythmic pattern, refractory convulsions and psychomotor retardation is very rare. Case reports. Two patients, one male and one female, were seen to have psychomotor retardation, erratic attacks of myoclonic convulsions, hypsarrhythmic encephalographic pattern and an increase in the urinary excretion of methylmalonic acid, as shown by gas chromatography and mass spectrometry, all of which supported a diagnosis of MMA in both cases. In one patient, the brain MRI with gadolinium showed lesions compatible with brain atrophy. Protein restrictions, the administration of vitamin B12 and L-carnitine re-established the normal neurological state and reduced the urinary excretion of methylmalonic acid in one of them. Conclusions. To the best of our knowledge these are the first cases of MMA that have been seen accompanied by hypsarrhythmia. The rareness of this clinical presentation with the characteristics described above make us suspect that we are dealing with a new clinical syndrome (AU)