Sea-blue histiocytes, lymphocytic cytosomes, movement disorder and 59Fe-uptake in basal ganglia: Hallervorden-Spatz disease or ceroid storage disease with abnormal isotope scan?

SCN8A Epilepsy, Developmental Encephalopathy, and Related Disorders

Understanding the precise genetic -basis of disease is one of the critical developments in medicine in the twenty-first century. Genetic testing has revolutionized the diagnosis and treatment of neurological diseases in children. Whole-genome and whole-exome sequencing have particularly been useful in understanding the genetic basis of childhood epileptic encephalopathies characterized by early-onset seizures with significant developmental impairment and regression. In this review we describe the identification of a new epileptic encephalopathy caused by a de novo mutation in the SCN8A gene, which encodes for Na_V1.6, a vital sodium channel in the central nervous system. SCN8A variants in patients with epilepsy result primarily in gain-of-function in Na_v1.6 and hyperexcitability of neurons in the central nervous system. Following the original discovery in 2012 of a de novo mutation in a child with developmental and epileptic encephalopathy (DEE), more than 400 individuals with SCN8A-related disorders have been identified. Clinical manifestations range from movement disorders or intellectual disability only to severe DEE, which includes epileptic encephalopathy with intractable multivariate seizure types, developmental impairment and regression, intellectual disability, and other neurological manifestations. Gain-of-function of the Na_v1.6 channel predicts effectiveness of sodium channel-blocking agents in the treatment of seizures, which has been corroborated by clinical experience. Nevertheless, treatment options remain limited and adverse effects are common. However, with the availability of a growing database of genetic and clinical data along with transfected cell lines and mouse models, more efficacious, targeted, and selective treatments may soon be feasible.

Precision medicine in pantothenate kinase-associated neurodegeneration

Neurodegeneration with brain iron accumulation is a broad term that describes a heterogeneous group of progressive and invalidating neurologic disorders in which iron deposits in certain brain areas, mainly the basal ganglia. The predominant clinical symptoms include spasticity, progressive dystonia, Parkinson’s disease-like symptoms, neuropsychiatric alterations, and retinal degeneration. Among the neurodegeneration with brain iron accumulation disorders, the most frequent subtype is pantothenate kinase-associated neurodegeneration (PKAN) caused by defects in the gene encoding the enzyme pantothenate kinase 2 (PANK2) which catalyzed the first reaction of the coenzyme A biosynthesis pathway. Currently there is no effective treatment to prevent the inexorable course of these disorders. The aim of this review is to open up a discussion on the utility of using cellular models derived from patients as a valuable tool for the development of precision medicine in PKAN. Recently, we have described that dermal fibroblasts obtained from PKAN patients can manifest the main pathological changes of the disease such as intracellular iron accumulation accompanied by large amounts of lipofuscin granules, mitochondrial dysfunction and a pronounced increase of markers of oxidative stress. In addition, PKAN fibroblasts showed a morphological senescence-like phenotype. Interestingly, pantothenate supplementation, the substrate of the PANK2 enzyme, corrected all pathophysiological alterations in responder PKAN fibroblasts with low/residual PANK2 enzyme expression. However, pantothenate treatment had no favourable effect on PKAN fibroblasts harbouring mutations associated with the expression of a truncated/incomplete protein. The correction of pathological alterations by pantothenate in individual mutations was also verified in induced neurons obtained by direct reprograming of PKAN fibroblasts. Our observations indicate that pantothenate supplementation can increase/stabilize the expression levels of PANK2 in specific mutations. Fibroblasts and induced neurons derived from patients can provide a useful tool for recognizing PKAN patients who can respond to pantothenate treatment. The presence of low but significant PANK2 expression which can be increased in particular mutations gives valuable information which can support the treatment with high dose of pantothenate. The evaluation of personalized treatments in vitro of fibroblasts and neuronal cells derived from PKAN patients with a wide range of pharmacological options currently available, and monitoring its effect on the pathophysiological changes, can help for a better therapeutic strategy. In addition, these cell models will be also useful for testing the efficacy of new therapeutic options developed in the future.

Pantothenate Rescues Iron Accumulation in Pantothenate Kinase-Associated Neurodegeneration Depending on the Type of Mutation

Neurodegeneration with brain iron accumulation (NBIA) is a group of inherited neurologic disorders in which iron accumulates in the basal ganglia resulting in progressive dystonia, spasticity, parkinsonism, neuropsychiatric abnormalities, and optic atrophy or retinal degeneration. The most prevalent form of NBIA is pantothenate kinase-associated neurodegeneration (PKAN) associated with mutations in the gene of pantothenate kinase 2 (PANK2), which is essential for coenzyme A (CoA) synthesis. There is no cure for NBIA nor is there a standard course of treatment. In the current work, we describe that fibroblasts derived from patients harbouring PANK2 mutations can reproduce many of the cellular pathological alterations found in the disease, such as intracellular iron and lipofuscin accumulation, increased oxidative stress, and mitochondrial dysfunction. Furthermore, mutant fibroblasts showed a characteristic senescent morphology. Treatment with pantothenate, the PANK2 enzyme substrate, was able to correct all pathological alterations in responder mutant fibroblasts with residual PANK2 enzyme expression. However, pantothenate had no effect on mutant fibroblasts with truncated/incomplete protein expression. The positive effect of pantothenate in particular mutations was also confirmed in induced neurons obtained by direct reprograming of mutant fibroblasts. Our results suggest that pantothenate treatment can stabilize the expression levels of PANK2 in selected mutations. These results encourage us to propose our screening model as a quick and easy way to detect pantothenate-responder patients with PANK2 mutations. The existence of residual enzyme expression in some affected individuals raises the possibility of treatment using high dose of pantothenate.

The Dystonias

Dystonia is a difficult problem for both the clinician and the scientist. It is sufficiently common to be seen by almost all physicians, yet uncommon enough to prevent any physician from gaining broad experience in its diagnosis and treatment. Each case represents a difficult challenge even to the specialist. The basic scientist is faced with investigating a disorder that is without relevant animal models and which is so rare that obtaining suitable tissue for study is a major obstacle. Dystonia may be idiopathic, or associated with lesions from many sources, including a variety of rare diseases. If idiopathic, it may be genetically transmitted or sporadic. If genetically transmitted, it may be generalized or focal, with symptoms varying in different members of the same family. It may be refractory to treatment, or it may respond to any one of a number of individual drugs that have very different mechanisms of action. For idiopathic dystonias, no clear method of genetic transmission has been established and no consistent pathology identified.

Hallervorden-Spatz disease

Hallervorden-Spatz disease (HSD) is a rare disorder characterized by progressive extrapyramidal dysfunction and dementia. Hallervorden and Spatz first described the disease, in 1922 as a form of familial brain degeneration characterized by iron deposition in the brain. Here we present four HSD cases with different clinical pictures.

Neurodegeneration with brain iron accumulation - clinical syndromes and neuroimaging

Iron participates in a wide array of cellular functions and is essential for normal neural development and physiology. However, if inappropriately managed, the transition metal is capable of generating neurotoxic reactive oxygen species. A number of hereditary conditions perturb body iron homeostasis and some, collectively referred to as neurodegeneration with brain iron accumulation (NBIA), promote pathological deposition of the metal predominantly or exclusively within the central nervous system (CNS). In this article, we discuss seven NBIA disorders with emphasis on the clinical syndromes and neuroimaging. The latter primarily entails magnetic resonance scanning using iron-sensitive sequences. The conditions considered are Friedreich ataxia (FA), pantothenate kinase 2-associated neurodegeneration (PKAN), PLA2G6-associated neurodegeneration (PLAN), FA2H-associated neurodegeneration (FAHN), Kufor-Rakeb disease (KRD), aceruloplasminemia, and neuroferritinopathy. An approach to differential diagnosis and the status of iron chelation therapy for several of these entities are presented. This article is part of a Special Issue entitled: Imaging Brain Aging and Neurodegenerative disease.

Defective FA2H leads to a novel form of neurodegeneration with brain iron accumulation (NBIA)

OBJECTIVE

Neurodegeneration with brain iron accumulation (NBIA) represents a distinctive phenotype of neurodegenerative disease for which several causative genes have been identified. The spectrum of neurologic disease associated with mutations in NBIA genes is broad, with phenotypes that range from infantile neurodegeneration and death in childhood to adult-onset parkinsonism-dystonia. Here we report the discovery of a novel gene that leads to a distinct form of NBIA.

METHODS

Using autozygosity mapping and candidate gene sequencing, we identified mutations in the fatty acid hydroxylase gene FA2H, newly implicating abnormalities of ceramide metabolism in the pathogenesis of NBIA.

RESULTS

Neuroimaging demonstrated T2 hypointensity in the globus pallidus, confluent T2 white matter hyperintensities, and profound pontocerebellar atrophy in affected members of two families. Phenotypically, affected family members exhibited spastic quadriparesis, ataxia, and dystonia with onset in childhood and episodic neurological decline. Analogous to what has been reported previously for PLA2G6, the phenotypic spectrum of FA2H mutations is diverse based on our findings and those of prior investigators, because FA2H mutations have been identified in both a form of hereditary spastic paraplegia (SPG35) and a progressive familial leukodystrophy.

INTERPRETATION

These findings link white matter degeneration and NBIA for the first time and implicate new signaling pathways in the genesis of NBIA.

Relaxation and susceptibility MRI characteristics in Hallervorden-Spatz syndrome

PURPOSE

To evaluate the imaging characteristics of the brain with respect to relaxation and susceptibility in Hallervorden-Spatz syndrome (HSS), a rare inherited neurodegenerative disorder (also referred to as neurodegeneration with brain iron accumulation).

MATERIALS AND METHODS

We reviewed 13 affected individuals who satisfied the inclusion criteria for HSS. Clinically, the patients were divided into two groups: early-childhood onset (age of onset before 10 years) and late-childhood onset (age of onset after 10 years). MRI was performed on 1.5T MR equipment. The imaging protocol included spin-echo (SE) T1-weighted (T1W), turbo spin-echo (TSE) T2W, and fluid attenuated inversion recovery (FLAIR) sequences in all patients. Susceptibility-weighted imaging (SWI) included a fast low-angle shot (FLASH) sequence in 10 patients and a blood oxygen level-dependent (BOLD) sequence in two patients.

RESULTS

All of the patients showed hyperintensity on T1WI and hypointensity on T2WI in the globus pallidi (GPs) bilaterally. Central or anteromedial hyperintensity was found in all but one patient. FLASH showed augmented hypointensity in 10 patients, and BOLD showed bilateral striatonigral abnormal pigmentation in two patients. MR spectroscopy (MRS) showed normal spectra in four patients, and a reduced NAA/Cho ratio in two.

CONCLUSION

MRI showed prominent signal abnormalities in the GP bilaterally in HSS. T1WI showed hyperintensity in all cases of HSS in addition to the "eye-of-the-tiger" sign on T2WI. SWI, FLASH, and BOLD demonstrated mineral deposition in the GP better than conventional imaging. Involvement of the striatonigral pathways was demonstrated for the first time on BOLD SWI.

Iron metabolism in Parkinsonian syndromes

Growing evidence suggests an involvement of iron in the pathophysiology of neurodegenerative diseases. Several of the diseases are associated with parkinsonian syndromes, induced by degeneration of basal ganglia regions that contain the highest amount of iron within the brain. The group of neurodegenerative disorders associated with parkinsonian syndromes with increased brain iron content can be devided into two groups: (1) parkinsonian syndromes associated with brain iron accumulation, including Parkinson's disease, diffuse Lewy body disease, parkinsonian type of multiple system atrophy, progressive supranuclear palsy, corticobasal ganglionic degeneration, and Westphal variant of Huntington's disease; and (2) monogenetically caused disturbances of brain iron metabolism associated with parkinsonian syndromes, including aceruloplasminemia, hereditary ferritinopathies affecting the basal ganglia, and panthotenate kinase associated neurodegeneration type 2. Although it is still a matter of debate whether iron accumulation is a primary cause or secondary event in the first group, there is no doubt that iron-induced oxidative stress contributes to neurodegeneration. Parallels concerning pathophysiological as well as clinical aspects can be drawn between disorders of both groups. Results from animal models and reduction of iron overload combined with at least partial relief of symptoms by application of iron chelators in patients of the second group give hope that targeting the iron overload might be one possibility to slow down the neurodegenerative cascade also in the first group of inevitably progressive neurodegenerative disorders.

Role of iron in neurodegenerative disorders

Although the pathophysiology underlying a number of neurodegenerative diseases is complex and, in many aspects, only partly understood, increased iron levels in pathologically relevant brain areas and iron-mediated oxidative stress seem to play a central role in many of them. Much has been learned from monogenetically caused disturbances of brain iron metabolism including pantothenate kinase-associated neurodegeneration type 2, hereditary ferritinopathies affecting the basal ganglia, and aceruloplasminemia that may well be applied to the most common neurodegenerative disorders associated with brain iron accumulation including Parkinson disease and Alzheimer disease. Iron-mediated oxidative stress in neurodegenerative diseases caused by other genetic pathways like Huntington disease and Friedreich ataxia underscore the complex interaction of this trace metal and genetic variations. Therapeutical strategies derived from application of iron chelators in monogenetically caused disturbances of brain iron metabolism and new iron and oxidative stress diminishing substances in animal models of Parkinson disease are promising and warrant further investigational effort.

Iron in neurodegenerative disorders

Increasing evidence implicates a role of iron in the pathogenesis of numerous neurodegenerative diseases due to its capacity to enhance production of toxic reactive radicals and to induce protein aggregation. The underlying mechanism of iron accumulation in areas of the brain specific for the respective disease, however, is still unknown. Recent molecular and biochemical studies provide new insights into the consequences of impairment of brain iron metabolism. This review summarizes our understanding of the regulation of iron in the brain and defines the current knowledge on the involvement of iron metabolism in neurodegenerative diseases with genetically determined iron accumulation in the brain.

Late-onset neurodegeneration with brain iron accumulation type 1: expanding the clinical spectrum

We report on two patients with pathologically proven neurodegeneration with brain iron accumulation type 1 (NBIA-1) with late onset and atypical presentations. One patient experienced gradual onset of shuffling gait, rigidity, bradykinesia, and increasing postural instability at age 85 years. He died a few weeks after developing acute hemiballismus at age 90 years. Histopathology revealed marked neuronal loss in the internal segment of the globus pallidum, astrocytosis, axonal spheroids, and extensive iron deposition consistent with NBIA-1. No additional lesions were found to explain the hemiballismus. The second patient experienced fulminant dementia evolving to total disability and death within 2 months. Autopsy showed typical NBIA-1 pathology. We conclude that NBIA-1 pathology can develop at any age, and that the phenotype should be expanded to include late-onset parkinsonism. The relationship to hemiballismus and adult-onset dementia is less clear.

Hallervorden-Spatz syndrome

The historic and current status of Hallervorden-Spatz syndrome diagnosis, classification, and therapies are discussed. A number of symptomatic therapies are available and should be used optimally for each patient. Although one gene locus has been identified, many patients do not manifest linkage to the NBIA1 locus (neurodegeneration with brain iron accumulation). Further investigation is necessary. The lack of understanding of the basic mechanisms that underlie the syndrome have hindered the development of more meaningful classification and definitive therapies. The recent report of a defect in a novel pantothenate kinase gene (PANK2) in Hallervorden-Spatz syndrome will undoubtedly lead the way to future advances in the diagnosis and management of the syndrome. The clarification of the role of oxidative distress in the pathophysiology of the syndrome will fill a large void in the understanding of the condition.

Intrafamilial phenotypic variability of Hallervorden-Spätz syndrome in a Tunisian family

We report clinical features, CT-scan and MRI findings of three siblings with Hallervorden-Spätz disease, one of them followed for more than 20years. Patient 1 presented at age 10 with progressive generalized dystonia. Five years later she had violent dystonic spasms with opisthotonos and marked oro-mandibular involvement. Later, dystonia stabilized and examination showed dysarthria, multiple deformities related to dystonic posturing, retinal degeneration and no cognitive impairment. Cerebral CT-scan showed bilateral pallidal lucencies and T2 cerebral MRI showed the "eye of the tiger" sign.Patient 2 developed delusions and hallucinations at age 18 with acute phases of hetero-aggressivity diagnosed as "schizophrenic" in a psychiatric hospital. At age 20, he developed oromandibular dystonia, severe dysarthria and epilepsy. Cerebral MRI showed the same "eye of the tiger" sign.Patient 3 presented at age 37 with isolated psychiatric features similar to those of patient 2, also diagnosed "schizophrenic" in a psychiatric hospital. Neurological examination showed mild postural tremor of the hands and intermittent cervical dystonia. He was stabilized with neuroleptic treatment.This family shows marked intrafamilial variability of age at onset, symptom at onset (with "schizophrenic" features unusually described and leading to misdiagnosis), clinical presentation (almost entirely dystonic in one patient and almost entirely psychiatric in two others) and course of the disease (slowly progressive in one sibling, rapidly deteriorating in the second and stabilization in the third). Classification and nosology of subtypes of HSD are discussed.

Antioxidant properties of clozapine and related neuroleptics

The antioxidant properties of clozapine and other related molecules were evaluated with the crocin bleaching test both in aqueous and non-aqueous environment. The tests of microsomal lipid peroxidation and carbonyl formation were also used. In aqueous solution, chlorpromazine and trifluoperazine appear particularly effective in the bleaching of crocin, while serotonin has an efficacy intermediate between those of phenothiazines and clozapine. The latter drug, on the other hand, in a non-aqueous medium shows an antioxidant power comparable to that of butylated hydroxytoluene, indicating that its antioxidant properties are better expressed in a hydrophobic environment of the type present in a biological membrane. In fact, in lipid peroxidation induced in microsomal membranes, clozapine, chlorpromazine, trifluoperazine and serotonin act as very good antioxidants; at low concentrations, clozapine appears to be the most efficient after butylated hydroxytoluene. Similarly, all these compounds markedly inhibit protein carbonyl formation, clozapine being one of the most efficient. Thus, under different in vitro experimental conditions, the neuroleptic drugs chlorpromazine and trifluoperazine and the antipsychotic substance clozapine act as very effective antioxidants; this property might, at least in part, be responsible for the physiological and clinical effects observed in vivo.

The pathophysiology of reactive oxygen intermediates in the central nervous system

Current evidence for the participation of free radicals in diseases of the central nervous system is reviewed. We conclude that the pathogenesis is based on a uniform mechanism: free radicals preferentially attack myelin, which contains easily peroxidizable phospholipids. The basal ganglia seem to be a brain area that is especially susceptible to radical damage which is possibly related to the synthesis of neurotransmitters. The clinical picture of the resulting cell death is dominated by convulsions and retardation in childhood and by psychomotoric disability and dementia in adulthood.

Clinical features of neuroleptic malignant syndrome in basal ganglia disease. Spontaneous presentation in a patient with Hallervorden-Spatz disease in the absence of neuroleptic drugs

Hallervorden-Spatz disease is a rare autosomal recessive disorder in which dopaminergic deficiency in the substantia nigra and its nigrostriatal projection has been identified. It is characterised by a slow but progressive course culminating in death. This case report describes a 13-year-old male, with a clinical diagnosis of Hallervorden-Spatz disease, who developed recurrent episodes of an acute illness, the features of which closely resembled those of the neuroleptic malignant syndrome. However, in this patient there had been no exposure to neuroleptic medication. The clinical events in this case suggest that dopaminergic hypoactivity, which is characteristic of Hallervorden-Spatz disease, can trigger episodes of neuroleptic malignant syndrome.

Doença de Hallervorden-Spatz: descrição de um caso

É relatado o caso de paciente do sexo masculino de 19 anos de idade, com quadro progressivo de distúrbio de comportamento e de postura distônica, com início nas extremidades do hemicorpo direito há 5 anos. Ao exame apresenta síndrome extrapiramidal e piramidal, sendo o diagnóstico de doença de Hallervorden-Spatz confirmado pela ressonância nuclear magnética do crânio (RM). O objetivo deste registro é ressaltar a importância da RM no estudo de doenças degenerativas do sistema nervoso.

Hallervorden-Spatz disease: clinical and MRI study of 11 cases diagnosed in life

The diagnosis of Hallervorden-Spatz disease (HSD) has usually been made post mortem, although the recent description of characteristic abnormalities in the globus pallidus has suggested the possibility of an in vivo diagnosis. We present the clinical histories, neurological features and MRI findings of 11 patients, diagnosed as having HSD. Generalized dystonia with predominance of oromandibular involvement, behavioural changes followed by dementia and retinal degeneration were present in all the patients. MRI pallidal abnormalities consisted of decreased signal intensity in T2-weighted images, compatible with iron deposits, and of a small area of hyperintensity in its internal segment ("eye of the tiger" sign). We propose that the combination of these neurological signs with these MRI findings could be considered as highly suggestive of a diagnosis of HSD in living patients.

Rapidly progressive autosomal dominant parkinsonism and dementia with pallido-ponto-nigral degeneration

We describe a family with nearly 300 members over 8 generations with 32 affected individuals who have an autosomal dominant neurodegenerative disease characterized by progressive parkinsonism with dystonia unrelated to medications, dementia, ocular motility abnormalities, pyramidal tract dysfunction, frontal lobe release signs, perseverative vocalizations, and urinary incontinence. The course is exceptionally aggressive; symptom onset and death consistently occur in the fifth decade. Positron emission tomographic studies with [18F]6-fluoro-L-dopa (6FD) were performed in 4 patients and 7 individuals at risk for development of the disease. All affected subjects had markedly reduced striatal uptake of 6FD (p less than 0.001). All individuals at risk had normal striatal uptake, but high 6FD uptake rate constants were noted in 3 of the 7 studied. Autopsy findings revealed severe neuronal loss with gliosis in substantia nigra, pontine tegmentum, and globus pallidus, with less involvement of the caudate and the putamen. There were no plaques, tangles, Lewy bodies, or amyloid bodies. This kindred appears to represent a neurodegenerative disease not heretofore described. We propose the following name for this new genetic disease: autosomal dominant parkinsonism and dementia with pallido-ponto-nigral degeneration.

Brain iron homeostasis

The anatomical and cellular distribution of non-haem iron, ferritin, transferrin, and the transferrin receptor have been studied in postmortem human brain and these studies, together with data on the uptake and transport of labeled iron, by the rat brain, have been used to elucidate the role of iron and other metal ions in certain neurological disorders. High levels of non-haem iron, mainly in the form of ferritin, are found in the extrapyramidal system, associated predominantly with glial cells. In contrast to non-haem iron, the density of transferrin receptors is highest in cortical and brainstem structures and appears to relate to the iron requirement of neurones for mitochondrial respiratory activity. Transferrin is synthesized within the brain by oligodendrocytes and the choroid plexus, and is present in neurones, consistent with receptor mediated uptake. The uptake of iron into the brain appears to be by a two-stage process involving initial deposition of iron in the brain capillary endothelium by serum transferrin, and subsequent transfer of iron to brain-derived transferrin and transport within the brain to sites with a high transferrin receptor density. A second, as yet unidentified mechanism, may be involved in the transfer of iron from neurones possessing transferrin receptors to sites of storage in glial cells in the extrapyramidal system. The distribution of iron and the transferrin receptor may be of relevance to iron-induced free radical formation and selective neuronal vulnerability in neurodegenerative disorders.

Globus pallidus calcification in Down syndrome with progressive neurologic deficits

We report a 10-year-old Down syndrome patient who developed dystonia, choreoathetosis, dysarthria, and dysphagia beginning with hemiparesis. Cranial computed tomography disclosed bilateral calcification in the globus pallidus which resembled a sign of premature aging. Conversely, the clinical course and magnetic resonance imaging findings resembled those of Hallervorden-Spatz syndrome.

Follow-up magnetic resonance imaging in Hallervorden-Spatz disease

Bilateral high signal emitting areas in the globus pallidus surrounded by low signal emitting areas have been described as a typical MRI finding in Hallervorden-Spatz disease (HSD). We made a diagnosis of HSD in an 11-year-old girl with progressive dystonia of 4 years duration who showed these typical MRI abnormalities. An initial MRI at the age of 9 was normal. Pathological confirmation of these typical MRI findings has not yet been described, but earlier reports as well as our case suggest that MRI may be helpful in making a clinical diagnosis of HSD. This case further shows that MRI may be normal in an early stage of the disease.

Effect of ferric nitrilotriacetate on rostral mesencephalic cells

After murine fetal cells from the rostral mesencephalic tegmentum were isolated, prepared, and cultured; neuronal and glial cells in primary mixed cell cultures were exposed to ferric nitrilotriacetate (Fe-NTA) at varying concentrations. Studies were performed at 23 days in culture after 14 day exposure to Fe-NTA. In addition to morphologic studies, biochemical assays including specific [3H]flunitrazepam (FLU) binding, clonazepam (CLO)-displaceable [3H]-FLU binding, Ro5-4864-displaceable [3H]-FLU binding, [3H]-FLU binding, [3H]dopamine (DA) uptake, [3H]haloperidol (HAL) binding, [3H]spiperone (SP) binding, glutamine synthetase activity (GS), and protein determinations were performed. The data demonstrate that chelated ferric iron has an adverse effect on these cells. The data also demonstrate that increasing concentrations of Fe-NTA resulted in massive neuronal dropout leaving the culture population virtually all glial; however, the specific binding of [3H]HAL and [3H]SP increased. There was a concomitant decrease in both glutamine synthetase activity and overall protein content. The mechanism of enhancement in the presence of Fe-NTA of [3H]HAL and [3H]SP binding is unknown and may be unique, but may be related to the known increase in D2 receptor ligand affinity in the presence of other multivalent cations (Ca2+ and Mg2+).

Osmiophilic deposits in cytosomes in Hallervorden-Spatz syndrome

A young child with Hallervorden-Spatz syndrome is presented. She was well until 8 years of age when she lost interest in activities and her school performance declined. At age 11 years, she began having episodes of blepharospasm, accompanied by bilateral ptosis and occasional episodes of oculogyric crisis. By age 12 years, her motor coordination had declined and she began to exhibit evidence of dementia, dystonia, dysarthria, and tremor. Motor incoordination, dystonia, and tremor progressed until the patient was wheel-chair-bound. Multiple tests were performed, including metabolic studies, magnetic resonance imaging, bone marrow biopsy, and electron microscopy of the buffy coat. Both bone marrow and buffy coat revealed inclusions in the cytosomes which were granular and osmiophilic. To our knowledge, this is the third case report of inclusion bodies found in patients with manifestations of Hallervorden-Spatz syndrome. These findings suggest that obtaining a buffy coat and bone marrow biopsy may aid in the diagnosis of Hallervorden-Spatz syndrome and ultimately provide information regarding etiology.

Effect of ferric nitrilotriacetate on predominantly cortical glial cell cultures

Cultured glial cells were exposed to ferric nitrilotriacetate (Fe-NTA) at varying concentrations. Studies of the exposed glial cells were performed at days 29 and 36 post-conceptional age (culture days 8 and 15). In addition to morphologic studies, biochemical assays including [3H]-flunitrazepam (FLU) specific binding, Ro5-4864-displaceable 3H-FLU binding, and protein determinations were performed. At day 29 post-conceptional age, significant decreases in 3H-FLU specific binding, Ro5-4864-displaceable 3H-FLU binding, and protein determinations were discernible only in the presence of 100 microM Fe-NTA. At day 36 post-conceptional age 3H-FLU specific binding was significantly decreased at 20, 60, and 100 microM Fe-NTA concentrations, while Ro5-4864-displaceable 3H-FLU binding and protein determinations were significantly reduced at 60 and 100 microM Fe-NTA concentrations. The effects of Fe-NTA exposure appear to be both concentration and duration-of-exposure related. When compared to previously reported neuronal cell culture studies utilizing 3H-FLU specific binding, Ro5-4864-displaceable 3H-FLU binding, and protein determinations, glial cells appear to be significantly more resistant to chelated iron exposure.

Effect of ferric nitrilotriacetate on predominantly cortical neuronal cell cultures

Predominately neuronal cell cultures were produced as described in previous communications. Neuronal cells were exposed to ferric nitrilotriacetate (Fe-NTA) at varying concentrations. Studies of the neuronal cells were performed at 13 and 20 days in culture. In addition to morphologic studies, biochemical assays including choline acetyltransferase (ChAT) activity, specific [3H]flunitrazepam (FLU) binding, clonazepam (CLO)-displaceable [3H]FLU binding, Ro5-4864-displaceable [3H]FLU binding, high-affinity [3H]GABA uptake, and protein determinations were performed. The data demonstrate that chelated ferric iron has an adverse effect on predominately neuronal cultures after 7 days of exposure as measured by choline acetyltransferase activity, while other measures remained unaffected; however, after 14 days of exposure all measures were significantly decreased. The effects of Fe-NTA exposure appear to be both concentration and duration-of-exposure related.

Late onset parkinsonian syndrome in Hallervorden-Spatz disease

Two siblings, from consanguineous parents, developed in their twenties a Parkinsonian syndrome. In the elder, the disease evolved for 13 years and the necropsic study was diagnostic of Hallervorden-Spatz disease. The younger sibling is severely affected after 12 years of the disorder. Several CT and one MR studies done in this patient during the last 4 years have been normal. Ultrastructural studies of the bone marrow histiocytes and blood lymphocytes disclosed peculiar inclusions. Bromocriptine in low doses proved to be a beneficial therapy for this patient.

CT appearance of low attenuation areas in basal ganglia in childhood: report of 23 cases

Low attenuation areas were seen at CT in the basal ganglia of 23 patients aged less than 15 years. The relationship between CT images and pathological findings is investigated and the differential diagnosis is made.

Transferrin binding by mammalian cortical cells

Predominantly neuronal (neuronal) or non-neuronal (glial) cerebral cortical cell cultures were employed to study the kinetics and changes with maturation of 125I-diferric-transferrin uptake. The diferric-transferrin association curve of neuronal cultures at 37 degrees C was nonphasic and indicated equilibrium at 90 minutes. Dissociation was completed by 70 minutes. Diferric-transferrin specific uptake (80% of total) in neuronal cells (evaluated at days 6, 9, 13, 16, and 23 in culture) increased with maturation. Scatchard transformation of the data revealed increasing Bmax from day 6 to day 16 in culture (1626 to 2740 fmoles/mg protein). However, the K uptake was statistically unchanged over time and equaled 48.7 +/- 13.9 nM (mean +/- SD). In contrast, association studies of glial cultures documented equilibrium by 45 minutes and dissociation by 40 minutes. The concentration curves for diferric-transferrin uptake in glial cells, evaluated at days 11, 15, and 18 in culture, revealed virtually identical uptake at the three ages studied, but the percent specific uptake (58%) was less than for neurons (88%). Scatchard transformation of the data revealed no statistical alteration of Bmax or K uptake from days 11 to 18 in culture. Bmax ranged from 595 to 751 fmol/mg protein; overall K uptake was 48.3 +/- 13.2 nM (mean +/- SD).

Lymphocyte autofluorescence: a screening procedure for neurodegenerative diseases

We examined the buffy coats from 12 consecutive patients with neurodegenerative diseases to determine the value of autofluorescence study by fluorescence microscopy in parallel with electron microscopy, as a rapid and inexpensive screening procedure for lymphocyte inclusions characteristic of neuronal ceroidlipofuscinoses. Four patients (3 with neuronal ceroidlipofuscinoses and 1 with Hallervorden-Spatz syndrome) had discrete, yellow-orange, 1-2 microns autofluorescent granules in the cytoplasm of some lymphocytes. These granules corresponded to characteristic inclusions of neuronal ceroidlipofuscinoses demonstrated by electron microscopy. Five patients (4 undiagnosed or nonspecific disease, and 1 with Leber congenital amaurosis) had hazy green cytoplasmic autofluorescence which correlated with parallel tubular arrays in lymphocytes. The 3 patients with no autofluorescence had no ultrastructural lymphocytic inclusions. We conclude that buffy coat autofluorescence is a rapid and inexpensive method of identifying specimens that require electron microscopic confirmation, and the absence of autofluorescence of lymphocytes in a buffy coat specimen eliminates the necessity for electron microscopic examination. However, characteristic ultrastructural inclusions associated with neurodegenerative diseases may occur in other tissues, such as skin and conjunctiva.

Chloroquine reduces neuronal and glial iron uptake

The effect of chloroquine, a lysosomotropic agent, on iron uptake into neuronal and glial cell cultures is reported. Chloroquine significantly inhibited iron uptake in both neuronal and glial cells. These findings suggest that iron transport into both neuronal and glial cells is mediated by the transferrin-iron complex.

Iron uptake by glial cells

Dynamic studies of iron metabolism in brain are generally unavailable despite the fact that a number of neurologic conditions are associated with excessive accumulation of iron in central nervous tissue. Cortical non-neuronal (glial) cultures were prepared from fetal mouse brain. After 13 days the cultures were exposed to radiolabeled iron. Brisk and linear total iron uptake and ferritin iron uptake occurred over 4 hours. When methylamine or ammonium chloride was added, (both known inhibitors of transferrin iron release because of their lysosomotropic properties), total iron uptake was diminished. Further studies indicated that methylamine inhibits glial cell ferritin iron incorporation. Glial cell iron transport is similar to previously reported neuronal cell iron transport (1) but glial cell iron uptake proceeds at a faster rate and is more susceptible to the inhibition of certain lysosomotropic agents. The data reinforces the likelihood that iron uptake by nervous tissues is transferrin-mediated.

The effect of iron on mammalian cortical neurons in culture

We added iron in the ferric form to predominantly neuronal, cortical cell cultures, and determined clonazepam-displaceable [3H]diazepam binding, choline acetyltransferase activity, high-affinity [3H]GABA uptake, and glutamic acid decarboxylase activity. Chronic exposure (14 days) to low concentrations (0.01, 0.04, and 0.1 micrograms/ml) of added ferric iron resulted in a significant decrease in each of the measures studied.

Hemidystonia: a report of 22 patients and a review of the literature

Hemidystonia defined as involuntary, sustained posturing of the unilateral arm, leg, and face was studied in 12 male and 10 female patients. Hemidystonia was caused by cerebrovascular disease in eight patients, perinatal trauma or childhood injury in four, head trauma and its sequelae in three, neuronal storage disorders in two, neurodegenerative disease in two, lesions after thalamotomy in two, and presumed encephalitis in one. Sixteen patients (73%) had CT evidence of contralateral basal ganglia damage, history of hemiparesis, or both. Brain damage before 7 years of age produced contralateral hemidystonia with a mean delay of 9-7 years. In older patients hemidystonia appeared within 6 months after injury. Hemidystonia may result from a disconnection between the striatum and the thalamus with relative preservation of the corticospinal pathways.

A new form of sea-blue histiocytosis associated with progressive anterior horn cell and axonal degeneration

A 15-year-old girl evidenced a slowly progressive central nervous system degenerative disorder. The illness had begun and progressed between ages 1 and 12 years, with ataxia, spasticity, choreoathetosis, early-onset seizures (which later ceased), and mild retardation. At age 13 she had developed rapidly progressive generalized weakness and atrophy, indicating peripheral nervous system involvement. Laboratory investigation revealed the presence of sea-blue histiocytes in the bone marrow without evidence of a disorder of sphingolipid metabolism or neuronal ceroid lipofuscinosis. Muscle biopsy showed large- and small-group atrophy, and sural nerve biopsy demonstrated axonal degeneration. This patient's illness appears to be a hitherto undescribed form of "sea-blue histiocytosis" associated with neurological dysfunction in children.

Iron uptake by mammalian cortical neurons

Although iron accumulates in the brain in a number of pathological conditions, including Hallervorden-Spatz syndrome, Parkinson's disease, and neurosyphilis, studies of brain iron metabolism have been performed only rarely. Neuronal-enriched cultures were prepared from fetal mouse brain. After 18 days the cells were exposed to radiolabeled iron. Total iron uptake and incorporation into ferritin were rapid and linear over four hours. The addition of either methylamine or ammonium chloride, both known blockers of transferrin-iron release through their lysosomotropic properties, inhibited total iron uptake. Methylamine also inhibited the rate of ferritin-iron incorporation, most likely by interfering with transferrin-iron release. The data suggest that neuronal iron transport, much like that in other mammalian tissues, is transferrin mediated and that blockers of transferrin-iron release may be of value in conditions in which there is brain iron overload.

Idiopathic torsion dystonia associated with lesions of the basal ganglia

We report two siblings who are suffering from a dystonic syndrome, clinically indistinguishable from idiopathic torsion dystonia (dystonia musculorum deformans) but with cranial computerized tomographic scan findings of basal ganglia lesions, similar to that reported in Wilson's disease. The occurrence of the disorder in the same sibship suggests an autosomal recessive mode of inheritance and may represent another variety of the syndrome of idiopathic torsion dystonia.