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Results for “Multiple System Atrophy”

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At least 1,639 records · Page 91Linked to original sources
PubMed1997

Positron emission tomography in parkinsonism.

Positron emission tomography provides researchers and clinicians with information on cerebral blood flow, metabolic pathways or neurotransmission systems, which may help to understand the physiopathology of movement disorders. Studies of the nigrostriatal dopaminergic pathway and data on cerebral glucose metabolism contribute to discriminate between parkinsonian syndromes. New techniques for image processing and statistical analysis, and brain activation studies better emphasize dysfunction of cortico-subcortical neuronal networks responsible for movement disorders, or functional modification after therapeutic action.

Basal Ganglia↗
PubMed1998

[Reduction of apomorphine-induced rotation in rats with additional destruction of the pedunculopontine nucleus contralateral to the unilateral nigrostriatal lesion].

Pedunculopontine nucleus (PPN) has been proposed to be one of the responsible sites for dopamine agonist induced contraversive rotation in rats with unilateral dopaminergic denervation. However, previous experiments have not confirmed possible participation of PPN in this rotational behavior. To determine whether contralateral side of the PPN plays a vital role in this rotation, we investigated apomorphine induced rotation in rats with further destruction of unilateral PPN contralateral to the nigrostriatal lesion. First, rats with unilateral PPN lesioned with N-methyl-D aspartic acid (NMDA) showed contralateral rotation when they were injected with apomorphine 0.5 mg/kg s.c. Second, rats with right substantia nigra previously lesioned with 6-hydroxydopamine were microinjected with NMDA (PPN lesion group) or vehicle (sham lesion group) into the contralateral (left)side of the PPN. Contraversive rotation induced by apomorphine 0.05 mg/kg s.c. did not show any significant change in PPN lesion group as compared with sham lesion group. Whereas such rotation induced by apomorphine 0.5 mg/kg s.c. significantly reduced to 61% in PPN lesion group as compared with that in sham lesion group. These results could be interpreted as a partial cancellation of rotational activity to the contralateral side (left) by the potential rotational activity toward the opposite side (right) in rats with additional contralateral PPN lesion. Although PPN might not serve as an output route for the dopaminergic neurotransmission in the basal ganglia, PPN itself could rather induce some movement affecting the basal ganglia.

Animals↗
PubMedDate not supplied

Familial multiple system degeneration associated with iron deposition: determination of subcellular localization of elementary iron by energy-dispersive X-ray analysis.

We report an autopsy case characterized by iron deposition associated with multiple system degeneration. Although iron deposition was distributed as in Hallervorden Spatz syndrome, no spheroid was detectable. On the other hand, multiple system degeneration was observed mainly in the pallido-nigral and dentato-rubral systems which resembled pallido-nigro-luysian degeneration. However, the clinical course and manifestations, and the neuropathology of this case were not completely consistent with any previous report. Differential diagnosis and classification of the case are discussed, and the genetic diagnostic procedures are presented. We also investigated the subcellular localization of elemental iron in glial cells using energy-dispersive X-ray spectral analysis. A small amount of elementary iron was clearly demonstrated in some regions of membrane-bound electron-dense material presumably derived from lysosomes. Further accumulation of clinical and neuropathological data in such cases will provide some clues to discover the etiology and classification of multiple system degeneration that occurs in association with iron deposition.

Cytoplasm↗
PubMed1998

[Tremor as a symptom of organic brain damage in individuals of young age].

Cases of young patients with different diseases of nervous system in which tremor was the main symptom, clinical peculiarities of trembling hyperkinesis in essential tremor, in olivopontocerebellar degeneration, in strionigral atrophia, in residual phenomena of organic brain damages as well as their differences from functional hyperkinesia are characterized. The data are presented on comparative efficiency of different methods of examination.

Adolescent↗
PubMed1997

Correlative studies of MR findings with neuropathology in Shy-Drager syndrome and striatonigral degeneration.

OBJECTIVE: To determine the pathologic bases of the abnormal signal intensities detected on magnetic resonance imaging (MRI) in Shy-Drager syndrome (SDS) and striatonigral degeneration (SND). METHODS: The correlation of MRI and pathological findings was prospectively evaluated by postmortem scanning of the brain in a case of SDS and another of SND. MRI was performed by using a 1.0 T superconductive magnetic unit, with spin echo (SE) pulse sequences. The brain sections were prepared parallel to the MRI planes. The gross and microscopic pathological studies were conducted according to the corresponding abnormal signal intensities on MRI. RESULTS: In SDS, abnormal hypointense signals on T2 weighted MR images were symmetrically demonstrated in bilateral putamen, where a remarkable positive Prussian blue stain reaction was revealed on pathological examinations. In SND, MRI showed isointense signals on T1 weighted images and hyperintense signals on T2 weighted images in bilateral putamen, and the microscopic findings included necrosis, abundant reactive fibrillary astrocytes and prominence of capillary vascular networks, as well as marked lipofuscin. The number of neurons decreased in both cases. CONCLUSIONS: The demonstration of the abnormal signals in the putamen on MRI is of important value in establishing an antemortem diagnosis of SDS and SND.

Female↗
PubMed1998

Loss of dopamine-D2 receptor binding sites in Parkinsonian plus syndromes.

UNLABELLED: This study analyzed temporal changes of striatal dopamine-D2 receptor binding during the course of different extrapyramidal movement disorders using 123I-iodobenzamide (IBZM) SPECT. METHODS: Eighteen patients (9 with Parkinson's disease, 9 with parkinsonian plus syndrome) were followed for 11-53 mo. Dopamine-D2 receptor binding was assessed using 123I-IBZM SPECT at the beginning and at the end of the follow-up period. SPECT data were acquired 120 min postinjection of 3-5 mCi 123I-IBZM. A semiautomated algorithm was applied to the raw data for semiquantitative evaluation of regional cerebral receptor binding. RESULTS: Intraobserver (r = 0.992) and interobserver (r = 0.930) variance was low for the semiautomated interpretation of the SPECT examination of the dopaminergic D2 receptor binding, reflecting a highly reproducible SPECT algorithm. Mean specific dopamine-D2 receptor binding was lower in patients with parkinsonian plus syndrome compared to patients with Parkinson's disease on the initial (p < 0.001) as well as the follow-up study (p < 0.001). In patients with Parkinson's disease, we observed an unaffected receptor binding compared to a reduced binding of radiotracer in patients with parkinsonian plus syndrome during the course of the disease (p < 0.001). CONCLUSION: During the follow-up, patients with Parkinson's disease showed a constant dopamine-D2 receptor binding. In contrast, patients with parkinsonian plus syndrome revealed a decline of the binding of dopamine-D2 receptor. These findings are in agreement with histopathological data that demonstrated a preserved dopamine-D2 receptor status in patients with Parkinson's disease and a decline of the dopamine-D2 receptors in patients with parkinsonian plus syndrome. SPECT examinations using 123I-IBZM are useful for assessing dynamic changes of dopamine-D2 receptors in extrapyramidal movement disorders. Semiquantitative SPECT evaluations may provide valuable information for clinical management and prognosis of the patient with extrapyramidal movement disorders.

Adult↗
PubMed2006

Accurate quantification methods to evaluate cervical cord atrophy in multiple sclerosis patients.

OBJECT: Automatic accurate measurement techniques are needed to increase reproducibility in the quantification of cervical cord area (CCA) with magnetic resonance (MR) imaging in the assessment of central nervous system (CNS) atrophy in multiple sclerosis (MS) patients. MATERIALS AND METHODS: Two segmentation methods were implemented: (1) spatial mean brightness level estimation (SMBLE), and (2) partial-volume modeling (PVM). These were evaluated with the inclusion of spinal cord inclination and/or partial-volume-effect corrections. An averaged manually segmented set was considered as reference. Thirty MR studies were used to compare the different methods. A set of 15 MS patients and 15 control subjects within a two-year longitudinal study were used to evaluate cord atrophy with the best method. Statistical evaluation was made by using an intraclass correlation coefficient and Bland-Altman comparisons. RESULTS: Partial-volume modeling with spinal cord inclination correction and partial-volume spinal-cord contour contribution estimation was the most accurate method. The longitudinal test showed a 4% decrease in CCA in MS patients with no significant reduction in control subjects. CONCLUSION: The automatic PVM cord-segmentation approach, taking into consideration the spinal-cord inclination and partial-volume treatment, provides reproducibility and increased accuracy in the evaluation of cord atrophy, allowing the monitoring of changes in MS patients.

Adolescent↗
PubMed2004

Pathogenesis of brain and spinal cord atrophy in multiple sclerosis.

For more than a century, multiple sclerosis was viewed as a disease process characterized by oligodendrocyte and myelin loss, and research into the pathogenesis of multiple sclerosis was mainly focused on the mechanisms of inflammation. However, with development of more sophisticated neuroimaging and molecular biology techniques, attention has shifted to new aspects of pathogenesis of multiple sclerosis: axonal loss and neurodegeneration. Evidence is increasing that tissue destruction, primarily axonal loss and neurodegeneration, is a key element in the pathogenesis of multiple sclerosis. In addition, it is now known that brain and spinal cord atrophy begins early in the disease process of multiple sclerosis and advances relentlessly throughout the course of the disease. Cumulative data suggest that axonal loss is the major determinant of progressive neurologic disability in patients with multiple sclerosis. Magnetic resonance imaging and magnetic resonance spectroscopy in patients with multiple sclerosis for < 5 years indicate brain atrophy and loss of axonal integrity. Neurodegeneration and axonal loss in patients with multiple sclerosis are initially accompanied by a local response from oligodendrocyte progenitor cells and some remyelination. However, these repair mechanisms eventually fail, and patients typically develop generalized brain atrophy, cognitive decline, and permanent disability. Although the exact mechanisms underlying central nervous system atrophy in patients with multiple sclerosis are largely unknown, evidence exists that atrophy may represent an epiphenomenon related to the effects of dynamic inflammation within the central nervous system, including demyelination, axonal injury, neuronal loss, Wallerian degeneration, and possibly iron deposition. This article summarizes the potential mechanisms involved in central nervous system atrophy in patients with multiple sclerosis.

Apoptosis↗
PubMed2004

Urodynamic findings in primary progressive multiple sclerosis are associated with increased volumes of plaques and atrophy in the central nervous system.

OBJECTIVE: Voiding dysfunction is more frequent in primary progressive multiple sclerosis (PPMS) than in other subtypes of MS. We investigated whether lower urinary tract disorders are reflected in the extent of changes in brain and spinal cord detected by magnetic resonance imaging (MRI). METHODS: Micturition symptoms and specific urodynamic findings in 24 patients with PPMS were related to MRI abnormalities as analysed by segmentation and volumetric analysis. RESULTS: Urgency and urge incontinence were the most frequent urinary symptoms (83 and 75 %), while detrusor sphincter dyssynergia (DSD) (71%), detrusor hyperreflexia (58%) and obstruction (58%) were the most common micturition dysfunctions. Comparison between patients with detrusor hyperreflexia and those with normal bladder function revealed higher volumes of T2-weighted plaques in the brains of former (P = 0.01). In patients with hypotonic bladder the total brain volume was smaller (P = 0.02) and the number of thoracic plaques in T2-weighted images higher (P = 0.02) compared to patients with normal bladder function. Furthermore, DSD was associated with a higher volume of T2-weighted plaques in the brain (P = 0.02). CONCLUSIONS: Voiding dysfunction in PPMS is associated with increasing brain and spinal cord abnormalities. Urodynamic investigation is, however, needed for specific definition of micturition disturbances and should be made before therapeutic decisions.

Atrophy↗
PubMed2002

Selective chronic stress-induced in vivo ERK1/2 hyperphosphorylation in medial prefrontocortical dendrites: implications for stress-related cortical pathology?

Stress has been shown to affect brain structural plasticity, promote long-term changes in multiple neurotransmitter systems and cause neuronal atrophy. However, the mechanisms involved in these stress-related neural alterations are still poorly understood. Mitogen-activated protein kinase (MAPK) cascades play a crucial role in the transduction of neurotrophic signal from the cell surface to the nucleus and are implicated in the modulation of synaptic plasticity and neuronal survival. An intriguing possibility is that stress might influence brain plasticity through its effects on selective members of such intracellular signalling cascades responsible for the transduction of neurotrophin signals. Here, we have investigated the effects of stress on the expression of three members of the MAPK/extracellular-regulated kinase (ERK) pathway such as phospho-ERK1, phospho-ERK2 and phospho-cAMP/calcium-responsive element-binding protein (CREB) in the adult rat brain. Male rats were subjected to mild footshocks and the patterns of protein expression were analysed after 21 consecutive days of stress. We found that chronic stress induced a pronounced and persistent ERK1/2 hyperphosphorylation in dendrites of the higher prefrontocortical layers (II and III) and a reduction of phospho-CREB expression in several cortical and subcortical regions. We hypothesized that defects in ERK signalling regulation combined with a reduced phospho-CREB activity may be a crucial mechanism by which sustained stress may induce atrophy of selective subpopulations of vulnerable cortical neurons and/or distal dendrites. Thus, ERK-mediated cortical abnormalities may represent a specific path by which chronic stress affects the functioning of cortical structures and causes selective neural network defects.

Animals↗
PubMed1994

The Haw River syndrome: dentatorubropallidoluysian atrophy (DRPLA) in an African-American family.

Haw River Syndrome (HRS) is a dominant neurodegenerative disease that has affected five generations of an African-American family in rural North Carolina. The disorder represents a unique spectrum of multiple system degenerations resembling Huntington's disease, spinocerebellar atrophy and dentatorubropallidoluysian atrophy (DRPLA), a neurodegenerative disease that has been primarily reported in Japan. Recently, DRPLA has been shown to be due to an expanded trinucleotide repeat located on chromosome 12pter-p12. We have genotyped this family and found HRS to be tightly linked to the DRPLA region. Further examination demonstrates that, despite their distinct cultural origins and clinical and pathological differences, HRS is caused by the same expanded CTG-B37 repeat as DRPLA.

Atrophy↗
PubMed1986

Mitochondrial dysfunction and spinocerebellar degenerations.

A simplified classification of the spinocerebellar degenerations is proposed. Axonal ataxias include Friedreich's ataxia and other conditions involving, primarily, neurons with very long axons. Multiple system degenerations include the various olivopontocerebellar atrophies and related disorders. Ataxic encephalopathies are diffuse diseases of the nervous system in which ataxia is a prominent clinical feature. Several lines of data suggest that mitochondrial damage is a common mechanism in the spinocerebellar degenerations. Reasonable pathophysiological mechanisms can be invoked, linking mitochondrial damage to the observed pathologies (including the many cases of intermediate on variant forms).

Ataxia↗