Congenital microcephaly and seizures due to 3-phosphoglycerate dehydrogenase deficiency: outcome of treatment with amino acids

Congenital microcephaly, intractable seizures and severe psychomotor retardation characterize 3-phosphoglycerate dehydrogenase (3-PGDH) deficiency, a disorder of L-serine biosynthesis. The enzyme defect results in low concentrations of serine and to a variable degree of glycine in plasma and cerebrospinal fluid. Short-term beneficial effects have been reported of oral treatment with the deficient amino acids. In this paper, we report the first follow-up data of amino acid therapy in five patients treated for 3-7.5 years. Different treatment regimes were used, but a favourable response to amino acids was observed in all patients. A major reduction in seizure frequency occurred in all patients; two patients became free of seizures. Amino acids were well tolerated and no adverse effects were documented. A progress of psychomotor development was only observed in one patient, diagnosed early and treated with a high dosage of L-serine. A favourable outcome of 3-PGDH deficiency depends on early diagnosis and treatment.

Unilateral posthaemorrhagic hydrocephalus in the neonatal period or later in infancy

Five infants who developed unilateral hydrocephalus associated with antenatal or perinatal intraventricular haemorrhage (IVH) in the neonatal period or later in infancy are reported. Unilateral hydrocephalus occurred following discharge home in four of our five cases, two of whom had been treated during the neonatal period with either serial lumbar punctures or punctures from a Rickham reservoir. An obstruction at the level of the foramen of Monro following a large subependymal matrix bleed appeared to be the underlying aetiology. These data suggest that infants who suffer a predominantly unilateral IVH, with or without parenchymal involvement, can subsequently develop unilateral hydrocephalus. Cranial ultrasound examinations should be repeated at regular intervals during the first year of life, as unilateral hydrocephalus can still develop after a period of apparent stabilization.

Correlation between neonatal cranial ultrasound, MRI in infancy and neurodevelopmental outcome in infants with a large intraventricular haemorrhage with or without unilateral parenchymal involvement

During a 7-year-period, 1625 infants of 34 weeks gestation or less were enrolled in a prospective ultrasound (US) study. One hundred and eleven (6.8%) infants developed a large intraventricular haemorrhage (IVH) with or without unilateral parenchymal involvement (PI). Fifty-six of these 111 infants survived (50.4%) and in 23 (41%) of them a magnetic resonance imaging (MRI) study was performed beyond 12 months corrected age. There appeared to be a good agreement between neonatal ultrasound findings and MRI changes noted in infancy. Of the 10 cases with a large IVH without PI (group A), seven had a VP shunt with complete decompression of previously enlarged ventricles. Six of these seven infants had periventricular hyperintensity (PVHI) but none developed cerebral palsy (CP). Two of the ten cases without a VP shunt had irregular ventricular enlargement (VE) with PVHI in one. Both developed CP. Seven cases showed thinning of the corpus callosum. Of the 13 cases with a large IVH associated with PI (group B), the site of the PI could still be recognised on MRI and the degree of communication of the porencephalic cyst (PC) with the lateral ventricles correlated well with neonatal US findings. On MRI, VE was present in only 6 cases. Wallerian degeneration was present in 9/13 infants and all but one developed a hemiplegia. In 12/13 cases there was thinning of the corpus callosum, either focal or diffuse. PVHI was present in all infants. In 6/13 PVHI was only present around the PC. Neurodevelopmental outcome differed for both groups. CP was only present in 2/10 infants in group A, compared to 11/ 13 in group B. Global delay, in the absence of CP, was more common in infants with a large IVH than in those with associated PI.

CONCLUSION

Combining neonatal US with MRI in infancy enhances our understanding of the long-term effects of severe haemorrhagic brain lesions, occurring in preterm infants.

Beneficial effects of L-serine and glycine in the management of seizures in 3-phosphoglycerate dehydrogenase deficiency

3-Phosphoglycerate dehydrogenase (3-PGDH) deficiency is an inborn error of serine biosynthesis. Patients are affected with congenital microcephaly, psychomotor retardation, and intractable seizures. The effects of oral treatment with amino acids were investigated in 2 siblings. L-Serine up to 500 mg/kg/day was not sufficient for seizure control. Addition of glycine 200 mg/kg/day resulted in complete disappearance of seizures. Electroencephalographic abnormalities gradually resolved after 6 months. We conclude that 3-PGDH can be treated effectively by a combination of L-serine and glycine.

Arteriovenous malformation of the vein of Galen in three neonates: emphasis on associated early ischaemic brain damage

Vein of Galen malformation is a rare intracranial disorder in newborns. In recent years the survival rate has improved due to improvement in endovascular treatment of this abnormality. We describe three neonates with a vein of Galen malformation for whom treatment was not attempted because of associated severe cerebral damage, of antenatal origin in two and of perinatal origin in the other. Autopsy was performed in two neonates. Periventricular leukomalacia was present in both cases, associated in one case with cortical infarction, gliosis and atrophy.

CONCLUSION

We recommend careful evaluation of associated cerebral damage prior to attempted treatment of the vein of Galen malformation.

Rapidly progressive enlargement of the fourth ventricle in the preterm infant with post-haemorrhagic ventricular dilatation

Six preterm infants who developed disproportionate enlargement of the 4th ventricle during the neonatal period, associated with post-haemorrhagic ventricular dilatation (PHVD), before shunt placement are reported. Five of the six preterm infants developed cyanotic spells and/or bradycardias at the time of rapid enlargement of the 4th ventricle, suggestive of raised posterior fossa pressure, which resolved following insertion of and drainage from a subcutaneous reservoir. In one of the three survivors an isolated 4th ventricle was subsequently diagnosed later in infancy, requiring drainage. These data suggest that a combination of an enlarged 4th ventricle on ultrasound and cyanotic spells and/or bradycardias should lead to rapid release of raised pressure in the posterior fossa. Long-term follow-up of these children is necessary, as isolation of the 4th ventricle can subsequently develop.

Cerebral proton magnetic resonance spectroscopic imaging in a neonate with tuberous sclerosis

On the basis of detection of cardiac tumours and an intracerebral subependymal mass, the diagnosis of tuberous sclerosis was made in a fullterm neonate. To evaluate cerebral metabolism cerebral mass proton magnetic resonance spectroscopic imaging (1H-MRSI) was performed. A local decrease in N-acetyl-aspartate (NAA), and an increase in choline signals were found. Lactate could neither be demonstrated in the subependynal nodule, nor in the surrounding tissue, thereby rendering the possibility of a high-grade malignant tumour less likely. No major changes were found at 3 and 6 months of age. The present study demonstrates, that 1H-MRSI may be helpful in metabolic evaluation of cerebral masses in patients with tuberous sclerosis.