Galactocerebrosidase activity in canine globoid leukodystrophy

In an investigation of canine globoid leukodystrophy, cerebroside beta-galactosidase activities were assayed in 24 brains from neonatal and older dogs and in 90 canine leukocyte pellets from nine samplings. The neonatal brains had significantly less enzyme activity than the brains of older dogs, which indicates a potential complication in making neonatal and fetal enzymatic diagnoses. For leukocytes, heterozygous activities averaged 51 percent and globoid leukodystrophy activities 18 percent of mean enzyme activity of normal leukocytes. Variability of leukocyte enzyme activities among the nine samplings was large, but within each sample, variability per genotypic category was moderate. A statistical model was developed to facilitate enzyme diagnosis in the dog and, by implication, in human globoid leukodystrophy and other sphingolipidoses.     

Adult metachromatic leukodystrophy: neurophysiologic findings

The visual and somatosensory evoked potentials were delayed in two cases of the adult form of metachromatic leukodystrophy. Brainstem auditory evoked potentials were normal. The conduction velocity along peripheral nerves was 50% slowed in one case and near normal in the other. The findings are compatible with demyelination in the central and peripheral nervous systems. The diagnosis of metachromatic leukodystrophy should be considered in cases of early dementia, with or without psychosis or other neurologic deficits, in which evoked potentials are delayed and peripheral nerve conduction is slowed.     

Metachromatic leukodystrophy manifesting as a schizophrenic disorder: computed tomographic correlation

A 32-year-old woman with a 12-year history of schizophrenia demonstrated symmetrical bifrontal and biparietal periventricular hypodensities on computed tomographic scan. Sural nerve biopsy and urine and leukocyte enzyme assay confirmed the diagnosis of metachromatic leukodystrophy. The computed tomographic correlate in an adult with metachromatic leukodystrophy in whom the psychiatric manifestations were the predominant clinical feature is described.     

Adult metachromatic leukodystrophy. Value of computed tomographic scanning and magnetic resonance imaging of the brain

Patients with adult-onset metachromatic leukodystrophy (MLD) often present with personality changes or deterioration of cognitive functions. Although rare, this form of MLD should be included in the differential diagnosis of psychotic and dementing disorders. The following case report describes a 38-year-old man with adult-onset MLD, who carried the diagnosis of schizophrenia and was treated as a schizophrenic for a number of years. Metachromatic leukodystrophy was initially suspected because of white matter abnormalities detected on computed tomographic scans and magnetic resonance images of the brain. The diagnosis of MLD was confirmed by the discovery of markedly reduced leukocyte arylsulfatase A activity. The computed tomographic and magnetic resonance imaging findings in MLD are reviewed.     

Computerized tomography in demyelinating disease of the young

We have used computerized tomography (CT) to look for evidence of cerebral demyelination in children with progressive neurologic disorders. Fourteen patients with a clinical diagnosis of a demyelinating disorder were examined by CT, and five had CT findings suggesting cerebral demyelination. In two patients with a so-called myelinoclastic demyelinating disease, CT showed asymmetric, circumscribed areas of diminished radiodensity, and in three patients with a leukodystrophy, scans showed diffuse symmetric areas of low density in the centrum ovale. Autopsy examination in one patient confirmed the diagnosis of sudanophilic leukodystrophy and substantiated the abnormalities suspected from CT.     

A case of pigmentary type of orthochromatic leukodystrophy with early onset and globoid cells

Summary We report herein a sporadic case of the pigmentary type of orthochromatic leukodystrophy with early onset and very rapid clinical course. The patient's development was normal until 2 years old, when he experienced visual disturbance. Rapid deterioration resulted in death 1.5 years after the onset. Metachromatic leukodystrophy, globoid cell leukodystrophy and adrenoleukodystrophy were excluded by biochemical assays. Autopsy findings were compatible with the diagnosis of the pigmentary type of orthochromatic leukodystrophy. However, there were unique findings of severe neuronal loss and the collection of globoid-like cells in the interface of the gray matter and the white matter. Immunohistochemical staining of myelin basic protein, proteolipid protein and galactocerebroside demonstrated that these myelin constituents were equally preserved in the posterior column, while absent in the lateral and anterior columns of the spinal cord.     

Tools for diagnosis of leukodystrophies and other disorders presenting with white matter disease

Advances in biochemical techniques, molecular genetics, and neuroimaging, particularly magnetic resonance imaging, have made possible the diagnosis of a significant proportion of leukodystrophies. A specific diagnosis allows the physician to give prognostic information, monitor for known complications, and ultimately may allow disease specific therapeutics. The purpose of this review is to familiarize the reader with pertinent tools in the diagnosis of leukodystrophies and other white matter disorders that may present with white matter disease. The first section discusses conditions that may mimic leukodystrophy and how to exclude them. Although not meant to be an exhaustive summary, several key disorders and their clinical, biochemical, and neuroimaging features are presented. The second section focuses on classically described leukodystrophies and their diagnosis. Finally, a third section provides a diagnostic algorithm to help the clinician in the diagnosis of the patient with leukodystrophy.     

Peripheral neuropathy in a child with Cree leukodystrophy

The authors describe peripheral nerve involvement in a 12-month-old boy with Cree leukodystrophy. Nerve conduction and genetic studies were performed during investigation of his leukodystrophy. Mutation analysis of the eukaryotic initiation factor 2B5 gene detected homozygosity of the R195 mutation, confirming the diagnosis of Cree leukodystrophy. Median and posterior tibial motor nerve conduction study results were normal, but sensory responses in the median nerves were unobtainable bilaterally, in keeping with a sensory axonal neuropathy. Somatosensory-evoked potentials were absent in the upper extremities and delayed in the lower extremities, confirming sensory nerve involvement. This degree of sensory nerve involvement has not been previously reported in patients with eukaryotic initiation factor 2B5-related disorders. Peripheral neuropathy should be looked for both clinically and with electrodiagnostic studies in patients with eukaryotic initiation factor 2B-related disorders.     

Magnetic resonance imaging in leukodystrophies of childhood

Magnetic resonance imaging (MRI) is particularly valuable in the diagnosis of childhood brain disorders with abnormal myelination because MRI may identify lesions not always seen with x-ray CT scans. We report the clinical and magnetic resonance findings of six children with leukodystrophy. T2 weighted (spin-echo) images disclosed striking asymmetric involvement of cerebral white matter, particularly in periventricular white matter and visual radiations. Calculated T1 values were significantly elevated in the children with leukodystrophy.     

Kindstötung und hebephrenes Syndrom bei metachromatischer Leukodystrophie

We report a patient with metachromatic leukodystrophy (MLD) with a first manifestation of homicide. On admission the patient showed a hebephrenia-like syndrome with inappropriate affect, thought disorder and behavioral changes. Magnetic resonance tomography (MRT) findings suggested a diagnosis of MLD, which was confirmed by a decreased activity of leucocyte arylsulfatase A and an excessive urinary sulfatide excretion.     

Genes involved in leukodystrophies: A glance at glial functions

Leukodystrophies are a group of orphan genetic diseases that primarily affect the white matter (WM) of the brain. The diagnosis and classification of these pathologies have been improved in the past decade thanks to the development of brain MRI, which allows the diagnosis of WM abnormalities in vivo and the continuous follow-up of patients. This article reviews recent advances made in leukodystrophy research by identifying causative genes. It focuses particularly on the genes involved in the hypomyelinated and vacuolating leukodystrophies, which provide new insights into the understanding of myelin formation and WM homeostasis.     

Leukodystrophies: recent developments in genetics, molecular biology, pathogenesis and treatment

The combined application of recently developed techniques for genetic and biochemical analysis, neuroimaging and the ability to create animal models has led to remarkable advances in the field of leukodystrophy research. The present review focuses on recent developments in X-linked adrenoleukodystrophy, Alexanders disease, Canavans disease, metachromatic leukodystrophy, globoid cell leukodystrophy (Krabbes disease) and Pelizaeus-Merzbacher disease, and briefly discusses new data on six other rare inherited leukodystrophies. Of the leukodystrophies, 12 can now be diagnosed precisely using noninvasive techniques, and the molecular defect has been identified in nine of these. Disease incidence can be reduced through genetic counselling. Presymptomatic diagnosis provides an opportunity for therapeutic intervention. Study of animal models facilitates elucidation of pathogenic mechanisms and identifies pathways that could be targeted by future therapies.     

MRI in the diagnosis of congenital white matter diseases and other neurodegenerative diseases]

The results of cranial magnetic resonance imaging in 76 children (aged 3 weeks--17 years) with neurometabolic or other neurodegenerative diseases are presented. The number of diagnosed diseases was 22. MR symptomatology of 11 of them is presented. The list of characteristic images includes metachromatic leukodystrophy, mucopolysaccharidoses, X-linked adrenoleukodystrophy, Leigh, Menkes and Pelizaeus-Merzbacher diseases, glutaric aciduria type I, Canavan disease, neuronal ceroid lipofuscinosis, Hallervorden-Spatz and Huntington diseases. The diagnosis of neurometabolic/neurodegenerative diseases cannot be based on MRI alone but in some of them (metachromatic leukodystrophy, adrenoleukodystrophy, Leigh and Menkes diseases, glutaric aciduria type I, Canavan and Hallervorden-Spatz diseases) MRI can strongly suggest the diagnosis.     

Photoparoxysmal response in late infantile neuronal ceroid-lipofuscinosis

A patient presented with rapid developmental regression whose MRI findings suggested a leukodystrophy, but nerve, muscle, skin, and bone marrow biopsies were unrevealing. A characteristic photoparoxysmal response on electroencephalogram provided an important clue for the correct diagnosis of late infantile neuronal ceroid-lipofuscinosis, which was confirmed later with electron microscope examination of a brain biopsy. In patients with rapid neurologic deterioration, diagnosis of neuronal ceroid-lipofuscinosis should be considered and an electroencephalogram should be performed using photic stimulation to look for characteristic findings.     

Adult-onset autosomal dominant leukodystrophy without early autonomic dysfunctions linked to lamin B1 duplication: a phenotypic variant

The early presentation of autonomic dysfunctions at the disease onset has been considered the mandatory clinical feature in adult-onset autosomal dominant leukodystrophy, which is a rarely recognised leukodystrophy caused by duplication of the lamin B1 gene. We report the first family with adult-onset autosomal dominant leukodystrophy and lamin B1 duplication, without the distinguishing early-appearing autonomic dysfunctions. Subjects from three consecutive generations of a multi-generational Serbian family affected by adult-onset autosomal dominant leukodystrophy underwent clinical, biochemical, neurophysiological, neuroradiological, and genetic studies. The patients atypically exhibited late autonomic dysfunctions commencing at the disease end-stages in some. Genetic findings of lamin B1 duplication verified adult-onset autosomal dominant leukodystrophy, which was supported also by neuroimaging studies. Exclusively, proton magnetic spectroscopy of the brain revealed a possibility of neuro-axonal damage in the white matter lesions, while magnetic resonance imaging of the spinal cord excluded spinal myelin affection as a required finding in this leukodystrophy. The detection of lamin B1 duplication, even when autonomic dysfunctions do not precede the other symptoms of the disease, proves for the first time that lamin B1-duplicated adult-onset autosomal dominant leukodystrophy may have a phenotypic variant with delayed autonomic dysfunctions. Prior to this report, such a phenotype had been speculated to represent an entity different from lamin B1-duplicated leukodystrophy. Hereby we confirm the underlying role of lamin B1 duplication, regardless of the autonomic malfunction onset in this disorder. It is the only report on adult-onset autosomal dominant leukodystrophy from Southeastern Europe.     

Biochemical diagnosis of Canavan disease

Canavan disease (CD) is a rare autosomal recessive disorder characterized by macrocephaly and progressive leukodystrophy. Up to now biopsy or necropsy were required to define the diagnosis. Recently the disease has been related to N-acetylaspartic aciduria and deficiency of aspartoacylase, an enzyme possibly involved in the myelin synthesis. These biochemical findings have provided a diagnostic marker for the disease. We report a new case of infantile CD in which the demonstration of N-acetylaspartic aciduria and a marked deficiency of aspartoacylase activity confirmed the diagnosis.     

Krabbe's disease (globoid cell leukodystrophy). Apropos of 5 cases]

A clinical study on five cases of Krabbe's disease (globoid cell leukodystrophy) was performed. A final diagnosis was done either with post-mortem study (two cases) or by enzymatic assays carried on cultured fibroblasts (two cases). Peripheral nerve biopsy for electron microscopy was performed in all cases, and the ultrastructural alterations characteristics of Krabbe's disease were always found. The authors emphasize the suggestive clinical and laboratory data which enable the diagnosis of Krabbe's disease in the absence of the ultrastructural exam of peripheral nerve, or the enzymatic assays not performed in this country.     

Pitfalls in the diagnosis of multiple sulfatase deficiency

Multiple sulfatase deficiency (MSD, OMIM 272200) is an autosomal recessive leukodystrophy associated with the deficiency of several, in total seven, sulfatases. The disorder is clinically and biochemically variable. The clinical picture combines features of mucopolysaccharidosis and metachromatic leukodystrophy (MLD, OMIM 250100) in a variable spectrum. Here we report a 3-year old Iranian girl with an MLD-like presentation of MSD. Arylsulfatase A deficiency and sulfatide excretion were found. Differently from what was previously reported in Multiple sulfatase deficiency (MSD, OMIM 272200) is an autosomal recessive leukodystrophy associated with the deficiency of several, in total seven, sulfatases. The disorder is clinically and biochemically variable. The clinical picture combines features of mucopolysaccharidosis and metachromatic leukodystrophy (MLD, OMIM 250100) in a variable spectrum. Here we report a 3-year old Iranian girl with an MLD-like presentation of MSD. Arylsulfatase A deficiency and sulfatide excretion the literature, this girl never showed abnormal mucopolysaccharide excretion in the urine. There were no additional visceral or skeletal signs. She was originally diagnosed as having MLD. Only when she developed ichthyosis were seven additional sulfatases measured. In leukocytes, arylsulfatase A, steroid sulfatase and N-acetylglucosamine-6 sulfatase were profoundly deficient, while iduronate-2 sulfatase and arylsulfatase B were moderately reduced. In fibroblasts, N-acetylglucosamine-6 sulfatase was deficient, while arylsulfatase A was moderately reduced. This case illustrates the possible pitfalls in the clinical and laboratory diagnosis of MSD.     

Early thalamic and cortical hypometabolism in adult-onset dementia due to metachromatic leukodystrophy.

A case of early-onset adult dementia with family history of dementia is reported, characterised by neuropsychological deficits, suggesting frontal involvement, with mild non specific white matter abnormalities on CT scan. Familial Alzheimer's disease was suspected but the neuropathological diagnosis on brain biopsy was metachromatic leukodystrophy. 18FDG-PET revealed a very peculiar pattern of metabolic impairment in thalamic areas, in medial and frontopolar regions, and in occipital lobes. Neuropsychological follow-up showed relatively stable difficulties of long-term memory and signs of frontal lobe dysfunction, similar to those observed in subcortical dementias. MRI subsequently showed periventricular leukoencephalopathy. The brain metabolic pattern observed in that case of metachromatic leukodystrophy was quite different from that reported in other types of dementia.     

Metachromatic leukodystrophy. Results of laboratory chemical, neurophysiologic, histologic and imaging procedures within the scope of a family study

Examining the members of a family the validity of chemical analysis, neurophysiology and neuroimaging for the diagnosis of metachromatic leukodystrophy (MLD) is discussed. As the arylsulfatase A is not decreased in all cases, the neuroimaging (cranial computerized tomography--at a less extend magnetic resonance imaging) gains a particular diagnostic significance. But neither for neuroimaging nor for neurophysiological findings the results are specific. The histological findings have to back up the diagnosis.