A Rare Cause of Myoclonus: A Cupric Conundrum.

A woman aged 22 years presented with a 3-year history of jerks when brushing her teeth and a tremor when carrying drinks. Examination revealed a bilateral jerky tremor, stimulus-sensitive myoclonus, and difficulty with tandem gait. Thyroid and liver function test results were normal, but she had rapidly progressive renal failure. Serum copper, ceruloplasmin, and manganese levels were normal, but her urinary copper level was elevated on 2 occasions. Pathological findings on organ biopsy prompted genetic testing to confirm the diagnosis. The differential diagnosis, tissue biopsy findings, and final genetic diagnosis are discussed.

[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.

Sialidosis type 1: cherry red spot-myoclonus syndrome with sialidase deficiency and altered electrophoretic mobility of some enzymes known to be glycoproteins. II. Enzymes studies.

Observations have been made on two brothers who had progressive ataxia, intention myoclonus and visual failure starting early in the third decade of life. Their parents were consanguineous. The brothers showed bilateral cherry red spots at the maculae and bilateral perinuclear cataracts; their intelligence was preserved. Urine was found to contain large amounts of sialylated oligosaccharides; cultured skin fibroblasts showed deficiency of the enzyme sialidase (neuraminidase). Studies on leucocytes and cultured skin fibroblasts showed aberrant electrophoretic mobilities of six enzymes all of which are known to be glycoproteins, and this has been attributed to excessive amounts of sialic acid on the enzyme molecules. The clinical features together with the biochemical findings indicate that these are further cases of the newly described condition Sialidosis Type 1 and it is suggested that the electrophoretic findings might be typical of the condition.

[Myoclonic encephalopathy in childhood (author's transl)]. / Die myoklonische Encephalopathie im Kindesalter.

Two new cases of infantile myoclonic encephalopathy are reported and a survey of literature is given. The disease is characterized by generalised myoclonic jerks in all striated muscles, by cerebellar ataxia and by fast, jerking, mostly conjugated irregular eye movements (opsoclonus). The disease develops mostly during late infancy and early childhood. The pathogenesis is unknown, probably it is caused by immunological reactions to various agents. Treatment with ACTH or corticosteroids leads to rapid remission of the initial neurological symptoms, but it is suggested that therapy does not prevent frequent sequelae of psychomotor retardation and speech distubances. Remarkably, there is the high coincidence of infantile myoclonic encephalopathy and neuroblastoma. Therefore it is necessary to keep in mind the possibility of a causative neuroblastoma in all children with myoclonic encephalopathy and to control repeatly radiological findings and urin-excretion of catecholamines as well as their metabolic products.

The excretion patterns of urinary glucosaminoglycans in a family with progressive familial myoclonus epilepsy.

The urinary excretion of uronic acid and the electrophoretic composition of urinary glucosaminoglycans were studied in 10 members of a family, of which 3 had progressive familial myoclonus epilepsy. This seems to be the first detailed investigation of the excretion of urinary glucosaminoglycans in patients suffering from this neurologic disease. The uronic acid excretion was found to be increased in the affected family members exclusively, whereas the excretion of the unaffected members were found within the normal limits characterized in this investigation. The urinary glucosaminoglycans could be separated into 5 fractions by electrophoresis. One or two of these fractions were increased in the urines of the three affected family members, the clinically most affected member showing the most abnormal electrophoretic results. An abnormal electrophoretic distribution of fractions was also found in the urines of 5 other members, clinically not affected. Only the maternal part of the family (mother and maternal grandmother) was shown to have a normal electrophoretic distribution of urinary glucosaminoglycans. The implication of these electrophoretic differences in the paternal and maternal family on the conditions for the development of the disease is discussed. The two fractions in question (designated fraction-0.65 and fraction-0.71) have until now been regarded as glycoproteins, but the present results show that they are true glucosaminoglycans (acid mucopolysaccharides), probably of low sulphate content.