bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modulation of postural wrist tremors by magnetic stimulation of the motor cortex in patients with Parkinson's disease or essential tremor and in normal subjects mimicking tremor
Authors: Britton T. C. , Thompson P. D. , Day B. L. , Rothwell J. C. , Findley L. J. , Marsden C. D. 
Published: January 2005

AbstractThe effect of magnetic brain stimulation on postural wrist tremor was studied in 10 patients with Parkinson's disease, 12 with hereditary essential tremor, and 10 normal subjects who mimicked tremor by making rapid alternating wrist movements. In all patients and normal subjects, magnetic brain stimulation over the contralateral motor cortex at an intensity approximately 10% above threshold produced the following sequence of events: (1) a small direct electromyographic (EMG) response, followed by (2) suppression of the rhythmic EMG activity responsible for the tremor, before (3) reappearance of the tremor time‐locked to the stimulus. It is concluded that magnetic brain stimulation over the motor cortex can modulate the oscillatory mechanisms responsible for the generation of postural tremors. Group analysis revealed that the time to reappearance of rhythmic EMG activity varied significantly with the period of parkinsonian postural tremors, but not with the period of essential or mimicked tremors. Magnetic stimulation also significantly shortened the period of parkinsonian postural tremors, but did not influence the period of essential or mimicked tremors. These behavioral differences indicate differences in the pathophysiological mechanisms underlying parkinsonian postural tremor and essential tremor.
Amygdaloid sclerosis in temporal lobe epilepsy
Authors: Hudson Lawrence P. , Munoz David G. , Miller Laurie , McLachlan Richard S. , Girvin John P. , Blume Warren T. 
Published: January 2005

AbstractHippocampal sclerosis is the sole abnormality found in approximately 65% of all temporal lobe specimens resected for intractable temporal lobe epilepsy. Up to 27% of en bloc temporal lobectomy specimens, howevery, show no definitive pathological changes. The lateral amygdaloid nucleus from 8 consecutive patients who underwent temporal lobectomy in whom no definitive hippocampal pathology was present and corresponding tissue from 8 consecutive patients with hippocampal sclerosis were subjected to quantitative estimation of neuronal density and astrogliosis. As compared to amygdaloid tissue from autopsy control subjects with no history of neurological disease, both the patient group with and that without hippocampal sclerosis consistently exhibited severe neuronal loss and gliosis with no quantitative differences between the two groups. Bliaded clinical review of both groups of patients revealed that the development of hippocampal sclerosis was associated with a history of early brain insult; this history was absent in patients with isolated amygdaloid sclerosis, Neuropsychological resting prior to surgery demonstrated that patients with hippocampal sclerosis displayed a greater degree of momory impairment than did those without hippocampal sclerosis. We conclude that amygdaloid sclerosis occurs in the absence of hippocampal sclerosis, and that these patients from a distinct group with no history of early brain insult and milder memory impairment than that seen in patients afficted with hippocampal sclerosis.
The effects of X monosomy on brain development: Monozygotic twins discorcant for Turner's syndrome
Authors: Reiss Allan L. , Freund Lisa , Plotnick Leslie , Baumgardner Thomas , Green Kathleen , Sozer Amanda C. , Reader Mark , Boehm Corinne , Denckla Martha B. 
Published: January 2005

AbstractMonosomy for the X chromosome is the most frequent cause of Turner's syndrome, a common clinical syndrome associated with particular physical and neurobehavioral features. The results from comprehensive assessment of prepubertal monozygotic female twins discordant for X monosomy are presented. Zygosity was established with DNA Fingerprinting and no evidence of chromosomal mosaicism was seen in either child. Physical features in the affected twin were relatively mild with respect to the full spectrum of physical malformations and disabilities associated with Turner's syndrome. The neurobehavioral phenotypes of the twins were compared. Although both sisters scored in the superior range of intelligence, the affected twin's Performance IQ was 18 points less than her sister, whereas Verbal IQ showed only a 3‐point difference between the sisters. Other relative differences were noted within the executive, visuospatial, and visuomotor domains of function. Behavioral evaluation indicated greater problems with attention, hyperactivity, and anxiety in the affected twin. Quantitative analysis of brain anatomy revealed evidence of both general and regional effects of X monosomy on neurodevelopment. Cerebrospinal fluid volume was increased by 25% in the affected twin compared with her sister with a corresponding decrease in gray matter volume. The right frontal, right parietal–occipital, and left parietal‐perisylvian regions showed the greatest discrepancy between the sisters with respect to increased cerebrospinal fluid and decreased gray matter volumes in the twin with X monosomy. Differences in the posterior fossa were also noted with a 50% relative increase in the volumes of the fourth ventricle and cisterna magna and a 10 to 15% relative reduction in size of the cerebellar vermis, pons, and medulla in the affected twin. The association between the neurobehavioral and neuroanatomical findings in the affected twin is discussed. The unique nature of the naturally occurring genetic phenomenon seen in this twin pair provides an opportunity to more fully elucidate the neurobehavioral phenotype associated with X monosomy and Turner's syndrome.
Cerebral white matter changes in acquired immunodeficiency syndrome dementia: Alterations of the blood‐brain barrier
Authors: Power Christopher , Kong Pei‐Ann , Crawford Thomas O. , Wesselingh Steven , Glass Jonathan D. , McArthur Justin C. , Trapp Bruce D. 
Published: January 2005

AbstractThe cause of acquired immunodeficiency syndrome (AIDS) dementia, which is a frequent late manifestation of human immunodeficiency virus (HIV) infection, is unknown but radiological and pathological studies have implicated alterations in subcortical white matter. To investigate the pathological basis of these white matter abnormalities, we performed an immunocytochemical and histological analysis of subcortical white matter from AIDS patients with and without dementia, from pre‐AIDS patients (asymptomatic HIV‐seropositive patients), and from HIV‐seronegative control subjects. Reduced intensity of Luxol fast blue staining, designated “diffuse myelin pallor,” was detected in 8 of 15 AIDS dementia patients, 3 of 13 AIDS nondemented patients, and none of the pre‐AIDS patients (n = 2) or control subjects (n = 9). In contrast to Luxol fast blue staining, sections stained immunocytochemically for myelin proteins did not show decreased staining intensities in regions of diffuse myelin pallor. In addition, neither demyelinated axons nor active demyelination were detected in light and electron micrographs of subcortical white matter from brains of patients with AIDS dementia. An increase in the number of perivascular macrophages and hypertrophy of astrocytes and microglia occurred in brain sections from HIV‐infected patients. These changes were not specific to dementia or regions of diffuse myelin pallor and they occurred in both gray and white matter. In contrast to the lack of myelin pathology in AIDS dementia brains, significant accumulations of serum proteins in white matter glia were detected in the brains of 12 of 12 patients with AIDS dementia and 6 of 12 AIDS patients without dementia. Serum protein‐immunopositive cortical neurons were detected in the frontal cortex of 11 of 12 patients with AIDS dementia and 3 of 12 nondemented AIDS patients. Seronegative control subjects showed minimal serum protein immunoreactivity in both cortex and white matter. We conclude therefore that alterations in the blood‐brain barrier and not demyelination contribute to the development of AIDS dementia.
Cytochrome c oxidase reaction improves histopathological assessment of zidovudine myopathy
Authors: Chariot Patrick , Monnet Isabelle , Gherardi Romain 
Published: January 2005

AbstractZidovudine can induce a mitochondrial myopathy with ragged‐red fibers and partial cytochrome c oxidase deficency. In an attempt to improve histological assessment of zidovudine myopathy, we evaluated cytochorme c oxidase histochemical reaction in the muscle of 10 patients with biopsy‐proven zidovudine myopathy (Group 1), 10 myopathic immunodeficiency virus (HIV)‐infected patients not treated by zidovudine who had an immunohistological profile of HIV‐associated myopathy or other neuromuscular disorders (Group 3). Among zidovudine receivers, cytochrome c oxidase deficiency was found in 10 of 10 patients from Group 1 and 7 of 10 from Group 2. No cytochrome c oxidase deficiency was observed in patients not treated by zidovudine. When present, cytochrome c oxidase‐negative fibers accounted for 2 to 28% of fibers, and there was no difference for the number of cytchrome c oxidase‐negative fibers between Group 1 and Group 2. Most patients with cytochrome c oxidase deficiency that could be evaluated clinically after muscle biopsy improved after withdrawal of zidovudine (5 of 7 in Group 1,5 of 5 in Group 2). Patients who did not improve had an HIV‐associated myopathy concurrently with zidovudine myopathy. We conclude that cytochrome c oxidase reaction may be used as a reliable marker of zidovudine mitochondrial toxicity in HIV‐infected patients with muscular symptoms.
Side of onset of motor symptoms influences cognition in Parkinson's disease
Authors: Tomer Rachel , Levin Bonnie E. , Weiner William J. 
Published: January 2005

AbstractStudies attempting to relate cognitive impairment to asymmetry of motor symptoms in Parkinson's disease (PD) have found contradictory results. We examined 88 patients with unilateral onset of idiopathic PD who underwent a comprehensive neuropsychological assessment, including language, visuosptial abilities, abstraction and reasoning, attention and mental tracking, set shifting, and memory. Patients whose motor signs began on the left side of the body consistently performed more poorly on the battery of cognitive measures than did patients with right‐side onset. Significant differences were found on immediate and delayed verbal recall, word retrieval, semantic verbal fluency, visuospatial analysis, abstract reasoning, attention span, and mental tracking. These differences could not be attributed to differences in the overall severity of motor symptoms at the time of cognitive assessment, or the current pattern of motor asymmetry. This finding suggests that damage to right‐hemisphere dopamine systems plays a disproportionately greater role in PD‐related cognitive decline than a presumably comparable left‐hemisphere dopamine depletion.
Chronic levodopa administration alters cerebral mitochondrial respiratory chain activity
Authors: Przedborski Serge , Jackson‐Lewis Vernice , Muthane Uday , Jiang Hong , Ferreira Mayra , Naini Ali B. , Fahn Stanley 
Published: January 2005

AbstractParkinson's disease (PD) is characterized mainly by a loss of nigrostriatal dopamine neurons. Thus far, the actual physiopathology of PD remains uncertain, although recent studies have found decreased activity of complex I, one of the enzymatic units of the mitochondrial respiratory chain, in various tissues of PD patients. Because most, if not all, of PD patients are treated chronically with levodopa, the precursor of dopamine, and because we have shown previously that catecholamines may alter mitochondrial respiration, we assessed the effects of chronic administration of levodopa on complex I activity in rat brain. We found that chronic administration of levodopa, at a dose used in PD patients, caused a significant reduction in complex I activity while it did not affect the activities of complex II, complex IV, and citrate synthase. Reduction in complex I activity correlated well with catecholamine innervation as the reduction was observed mainly in the striatum and substantia nigra and to a lesser extent in the frontal cortex but not in the cerebellum. Moreover, the levodopa‐induced decrease of complex I activity was reversible since activities at 1, 3, and 7 days after the last injection showed a progressive return to control values. Incubation of whole brain mitochondria in vitro showed that both levodopa and dopamine inhibit complex I activity in a dose‐ and time‐ dependent manner. In contrast, other compounds such as homovanillic acid, 3,4‐dihydroxyphenylacetic acid, and 3‐O‐methyl‐dopa were minimally effective. Reduced glutathione, ascorbate, superoxide dismutase, and catalase prevented the effect of levodopa and dopamine on complex I. Various inhibitors of monoamine oxidase also prevented the effect of dopamine. In agreement with a critical role of monoamine oxidase in this effect in vitro, we observed that noncatecholamine substrates of this enzyme such as serotonin and β‐phenylethylamine were potent inhibitors of complex I. However, autoxidation may also be involved in this process because the effect of levodopa, 6‐hydroxydopa, and 6‐hydroxydopamine on complex I activity was only partially suppressed by monoamine oxidase inhibitors. These observations demonstrate that the chronic administration of levodopa can cause alterations in mitochondrial respiratory chain activity in rats that are most likely related to an oxidative stress provoked by the increase in dopamine turnover. We suggest that this mechanism may exaggerate a mitochondrial defect already present in the brains of PD patients and thus may play a role in the progression of PD.
The mutation at nt 8993 of mitochondrial DNA is a common cause of Leigh's syndrome
Authors: Santorelli Filippo M. , Shanske Sara , Macaya Alfons , DeVivo Darryl C. , DiMauro Salvatore 
Published: January 2005

AbstractTwelve patients with Leigh's syndrome from 10 families harbored a T > G point mutation at nt 8993 of mtDNA. This mutation, initially associated with neurogenic weakness, ataxia, and retinitis pigmentosa, was later found to result in the Leigh phenotype when present in a high percentage. In our patients, the mutation was heteroplasmic, maternally inherited, and appeared to segregate rapidly within the pedigrees. Quantitative analysis revealed a good correlation between percentage of mutant mitochondrial genomes and severity of the clinical phenotype. The mutation was not found in > 200 patients with other mitochondrial encephalomyopathies or in controls. Mitochondrial enzyme activities were normal in all but 1 patient, and there were no ragged‐red fibers in the muscle biopsy. Lactic acidosis was present in 92% of patients. Our findings suggest that the mtDNA nt 8993 mutation is a relatively common cause of Leigh's syndrome.
Acute lumbosacral polyradiculopathy in acquired immunodeficiency syndrome: Experience in 23 patients
Authors: So Yuen T. , Olney Richard K. 
Published: January 2005

AbstractWe reviewed our experience in 23 patients with acquired immunodeficiency syndrome (AIDS) who had acute lumbosacral polyradiculopathy. The patients developed a distinctive syndrome of rapidly progressive flaccid paraparesis and areflexia that was frequently associated with sphincter disturbances. Persuasive laboratory evidence of a cytomegalovirus polyradiculopathy (polymorphonuclear pleocytosis or confirmatory cerebrospinal fluid culture) was found in 15 of the 23 patients. Treatment with ganciclovir in these patients led to clinical stabilization, although worsening during the first 2 weeks of treatment was common. Most patients with cytomegalovirus polyradiculopathy had severe residual deficits. Metastasis from systemic lymphoma accounted for the polyradiculopathy in 2 other patients. A more benign syndrome was identified in the remaining 6 patients. They generally had slower clinical progression and less severe neurological deficits at their nadir than did patients with cytomegalovirus polyradiculopathy. Unlike patients with cytomegalovirus infection, their cerebrospinal fluid showed a predominantly mononuclear pleocytosis. Moreover, spontaneous improvement without treatment was common. Our experience together with the published experience of others suggests that the acute lumbosacral polyradiculopathy in AIDS is a clinical syndrome with different etiologies and variable clinical outcome. Recognition of this heterogeneity is necessary for the management of individual patients, as well as the interpretation of treatment results.
Congenital Horner's syndrome does not alter Lisch nodule formation
Authors: Mindel Joel S. , Rubenstein Allan E. , Wallace Sibylle , Aron Alan M. , Halperin Jane 
Published: January 2005

AbstractA 21‐year‐old woman with neurofibromatosis type 1 (NF‐1) had a unilateral congenital Horner's syndrome with resultant hypopigmentation of the affected iris. Lisch nodules, which are melanocytic hamartomas, were similar in number, size, and pigmentation in both eyes. The present findings suggest that the formation of Lisch nodules is not influenced by the presence or absence of sympathetic innervation of the iris.
Organ‐specific autoantigens induce transforming growth factor‐β mRNA expression in mononuclear cells in multiple sclerosis and myasthenia gravis
Authors: Link Joanne , Fredrikson Sten , Söderström Mats , Olsson Tomas , Höjeberg Bo , Ljungdahl Åke , Link Hans 
Published: January 2005

AbstractMultiple sclerosis (MS) is characterized by patchy accumulations of inflammatory cells combined with demyelination. There are mononuclear cells in blood and cerebrospinal fluid of patients with MS that produce interferon‐γ and interleukin‐4 in response to myelin basic protein (MBP) and proteolipid protein (PLP). Here we describe autoantigen‐induced production of transforming growth factor‐β (TGF‐β). This multifunctional cytokine has inhibitory effects on the growth, differentiation, and effector functions of activated T cells. Blood and cerebrospinal fluid cells were exposed in short‐term cultures to MBP and PLP and, after hybridization with complementary DNA oligonucleotide probes, they were evaluated for TGF‐β mRNA expression. Patients with MS had higher numbers of MBP‐ and PLP‐responsive TGF‐β mRNA expressing cells in blood compared with control patients with other neurological diseases or myasthenia gravis and a five‐ and threefold further increment in their cerebrospinal fluid. In blood of patients with myasthenia gravis, where the acetylcholine receptor (AChR) is a target for autoaggressive immunity, there were increased levels of AChR‐responsive TGF‐β mRNA expressing cells. Thymectomized myasthenia gravis patients showed higher levels of TGF‐β mRNA expressing cells compared with patients not thymectomized. Numbers of cells responding to AChR in MS and MBP in myasthenia gravis did not differ from numbers found in absence of antigen. Patients with other neurological diseases showed infrequent and low responses to MBP, PLP, and AChR. Diseases with presumed autoimmune pathogenesis are associated with organ‐specific autoantigen‐induced TGF‐β production, which is increased after thymectomy.
Botulinum toxin‐A improves the rigidity of progressive supranuclear palsy
Authors: Polo Kathleen B. , Jabbari Bahman 
Published: January 2005

AbstractBotulinum toxin‐A (botox) can improve spasticity and decrease painful spasms in the affected limbs of patients with multiple sclerosis. We report significant improvement of muscle rigidity in the upper limbs after focal administration of botulinum toxin A to 2 patients with progressive supranuclear palsy.
Biochemical and fluorodopa positron emission tomographic findings in an asymptomatic carrier of the gene for dopa‐responsive dystonia
Authors: Takahashi Hirohide , Levine Robert A. , Galloway Matthew P. , Snow Barry J. , Calne Donald B. , Nygaard Torbjoern G. 
Published: January 2005

AbstractWe report cerebrospinal fluid monoamine metabolite analyses and 6‐[18F]fluoro‐1‐dopa positron emission tomography (FD‐PET) from an asymptomatic carrier of the gene for dopa‐responsive dystonia. Cerebrospinal fluid homovanillic acid, tetrahydrobiopterin, and neuropeterin concentrations were reduced in this man and in his affected children. His FD‐PET was normal, as we have previously found in dopa‐responsive dystonia. Neurological function and FD‐PET may be normal despite marked abnormality in dopamine metabolism.
Dopa‐responsive dystonia: Pathological and biochemical observations in a case
Authors: Rajput A. H. , Gibb W. R. G. , Zhong X. H. , Shannak K. S. , Kish S. , Chang L. G. , Hornykiewicz O. 
Published: January 2005

AbstractWe report the first neuropathological and neurochemical study of a patient with dopa‐responsive dystonia. She had onset of foot dystonia at age 5 years and by age 8 years it was generalized with prominent right leg and arm involvement. On levodopa 750 mg daily she had complete symptomatic improvement that was sustained for 11 years until death. Pathological studies revealed normal numbers of hypopigmented substantia nigra neurons, normal tyrosine hydroxylase (TH) immunoreactivity and TH protein in the SN, no inclusion bodies or gliosis, and no evidence of a degenerative process in the striatum. Biochemical studies revealed reduced dopamine in the substantia nigra and striatum (8% in the putamen and 18% of control in the caudate) with a similar but not identical subregional distribution as in idiopathic Parkinson's disease. In the striatum, TH protein and TH activity was reduced, with the loss more pronounced in the putamen than the caudate. The GBR 12935 binding to DA transporter was normal in the caudate and at the lower end of the range of control values in the putamen. We conclude that disturbed dopamine synthetic capacity or a reduced arborization of striatal dopamine terminals may be the major disturbance in dopa‐responsive dystonia.
Eye movements in parkinsonian syndromes
Authors: Vidailhet Marie , Rivaud Sophie , Gouider‐Khouja Neziha , Pillon Bernard , Bonnet Anne‐Marie , Gaymard Bertrand , Agid Yves , Pierrot‐Deseilligny Charles 
Published: January 2005

AbstractEye movements were recorded in 14 patients with Parkinson's disease (PD) in the “off” condition, 14 patients with striatonigral degeneration (SND), 10 patients with corticobasal degeneration (CBD), and 10 patients with progressive supranuclear palsy (PSP), with comparison with 12 control subjects. Vertical saccade paralysis was not observed in the PD, SND, and CBD groups but was present in 9 patients of 10 in the PSP group. In the PD and SND groups, horizontal reflexive visually guided saccade latency and accuracy were similar, and differed only slightly from those of controls. In the CBD group, saccade latency was significantly increased and correlated to an “apraxia score”; whereas, in the PSP group, saccade amplitude was significantly decreased. Thus, the abnormalities of both horizontal saccade parameters in the PSP group contrasted with those observed in the CBD group. The percentage of errors in the antisaccade task, an index of prefrontal dysfunction, was markedly increased only in the PSP group. The smooth pursuit gain was decreased in all groups but more severely in the PSP group. It may be concluded that saccade abnormalities are clearly different in SND, CBD, and PSP, and might help in early differential diagnosis in individual patients, but that SND cannot be differentiated from PD on the simple basis of eye movement abnormalities.