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1.
J Neurol Neurosurg Psychiatry ; 94(1): 57-61, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36319190

RESUMO

BACKGROUND: Obesity reportedly increases the risk for developing multiple sclerosis (MS), but little is known about its association with disability accumulation. METHODS: This nationwide longitudinal cohort study included 1066 individuals with newly diagnosed MS from the German National MS cohort. Expanded Disability Status Scale (EDSS) scores, relapse rates, MRI findings and choice of immunotherapy were compared at baseline and at years 2, 4 and 6 between obese (body mass index, BMI ≥30 kg/m2) and non-obese (BMI <30 kg/m2) patients and correlated with individual BMI values. RESULTS: Presence of obesity at disease onset was associated with higher disability at baseline and at 2, 4 and 6 years of follow-up (p<0.001). Median time to reach EDSS 3 was 0.99 years for patients with BMI ≥30 kg/m2 and 1.46 years for non-obese patients. Risk to reach EDSS 3 over 6 years was significantly increased in patients with BMI ≥30 kg/m2 compared with patients with BMI <30 kg/m2 after adjustment for sex, age, smoking (HR 1.87; 95% CI 1.3 to 2.6; log-rank test p<0.001) and independent of disease-modifying therapies. Obesity was not significantly associated with higher relapse rates, increased number of contrast-enhancing MRI lesions or higher MRI T2 lesion burden over 6 years of follow-up. CONCLUSIONS: Obesity in newly diagnosed patients with MS is associated with higher disease severity and poorer outcome. Obesity management could improve clinical outcome of MS.


Assuntos
Esclerose Múltipla Recidivante-Remitente , Esclerose Múltipla , Humanos , Esclerose Múltipla/complicações , Esclerose Múltipla/epidemiologia , Esclerose Múltipla/terapia , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Estudos Longitudinais , Imageamento por Ressonância Magnética , Obesidade/complicações , Obesidade/epidemiologia , Recidiva , Progressão da Doença
2.
J Neurol Neurosurg Psychiatry ; 92(9): 1007-1013, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33712515

RESUMO

OBJECTIVES: Alemtuzumab is effective in patients with active multiple sclerosis but has a complex safety profile, including the development of secondary autoimmunity. Most of patients enrolled in randomised clinical trials with alemtuzumab were either treatment naïve or pretreated with injectable substances. Other previous disease-modifying treatments (DMTs) were not used in the study cohorts, and therefore, associated risks might yet remain unidentified. METHODS: We retrospectively evaluated a prospective dual-centre alemtuzumab cohort of 170 patients. We examined the baseline characteristics as well as safety and effectiveness outcomes, including the time to first relapse, the time to 3 months confirmed disability worsening and the time to secondary autoimmunity. RESULTS: The regression analysis showed that, among all previously used DMTs, the pretreatment with fingolimod (n=33 HRs for the time to first relapse (HR 5.420, 95% CI 2.520 to 11.660; p<0.001)) and for the time to worsening of disability (HR 7.676, 95% CI 2.870 to 20.534; p<0.001). Additionally, patients pretreated with fingolimod were more likely to experience spinal relapses (55% vs 10% among previously naïve patients; p<0.001) and had an increased risk of secondary autoimmunity (HR 5.875, 95% CI 2.126 to 16.27; p<0.001). CONCLUSION: In the real-world setting, we demonstrated suboptimal disease control and increased risk of secondary autoimmunity following alemtuzumab, among patients previously treated with fingolimod. These data can provide guidance for improving MS therapeutic management.


Assuntos
Alemtuzumab/uso terapêutico , Imunossupressores/uso terapêutico , Esclerose Múltipla/tratamento farmacológico , Adulto , Alemtuzumab/efeitos adversos , Feminino , Humanos , Imunossupressores/efeitos adversos , Masculino , Estudos Prospectivos , Retratamento , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
3.
Ann Neurol ; 80(6): 946-951, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27774643

RESUMO

Animal models have implicated an integral role for coagulation factors in neuroinflammatory diseases such as multiple sclerosis (MS) beyond their role in hemostasis. However, their relevance in humans requires further elucidation. This study aimed to determine whether levels of coagulation factors differ between patients with neuroimmunological disorders and respective controls. Individuals suffering from relapsing-remitting and secondary progressive MS had significantly higher prothrombin and factor X levels than healthy donors, whereas levels were unchanged in primary progressive MS and neuromyelitis optica patients. Our study demonstrates that coagulation factors may be key mediators in neuroinflammation and may therefore provide future targets for therapeutic strategies. Ann Neurol 2016;80:946-951.


Assuntos
Fator X/metabolismo , Esclerose Múltipla Crônica Progressiva/sangue , Esclerose Múltipla Recidivante-Remitente/sangue , Protrombina/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Fatores de Coagulação Sanguínea/metabolismo , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neuromielite Óptica/sangue , Adulto Jovem
4.
Mult Scler ; 23(7): 1025-1030, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27481205

RESUMO

BACKGROUND: Distinct lesion topography in relapsing-remitting multiple sclerosis (RRMS) might be due to different antigen presentation and/or trafficking routes of immune cells into the central nervous system (CNS). OBJECTIVE: To investigate whether distinct lesion patterns in multiple sclerosis (MS) might be associated with a predominance of distinct circulating T-helper cell subset as well as their innate counterparts. METHODS: Flow cytometric analysis of lymphocytes derived from the peripheral blood of patients with exclusively cerebral (n = 20) or predominantly spinal (n = 12) disease manifestation. RESULTS: Patients with exclusively cerebral or preferential spinal lesion manifestation were associated with increased proportions of circulating granulocyte-macrophage colony-stimulating factor (GM-CSF) producing TH1 cells or interleukin (IL)-17-producing TH17 cells, respectively. In contrast, proportions of peripheral IL-17/IL-22-producing lymphoid tissue inducer (LTi), the innate counterpart of TH17 cells, were enhanced in RRMS patients with exclusively cerebral lesion topography. CONCLUSIONS: Distinct T-helper and T-helper-like innate lymphoid cell (ILC) subsets are associated with different lesion topography in RRMS.


Assuntos
Encéfalo/imunologia , Imunidade Inata , Linfócitos/imunologia , Esclerose Múltipla Recidivante-Remitente/imunologia , Medula Espinal/imunologia , Células Th1/imunologia , Células Th17/imunologia , Adulto , Idoso , Biomarcadores/sangue , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Estudos de Casos e Controles , Avaliação da Deficiência , Feminino , Citometria de Fluxo , Fator Estimulador de Colônias de Granulócitos e Macrófagos/sangue , Humanos , Imunofenotipagem/métodos , Interleucina-17/sangue , Interleucinas/sangue , Linfócitos/metabolismo , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla Recidivante-Remitente/sangue , Esclerose Múltipla Recidivante-Remitente/diagnóstico por imagem , Fenótipo , Medula Espinal/diagnóstico por imagem , Medula Espinal/metabolismo , Células Th1/metabolismo , Células Th17/metabolismo , Adulto Jovem , Interleucina 22
5.
Cerebrovasc Dis ; 39(5-6): 269-77, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25871403

RESUMO

BACKGROUND: An increasing number of stroke patients have to be supported by mechanical ventilation in intensive care units (ICU), with a relevant proportion of them requiring gradual withdrawal from a respirator. To date, weaning studies have focused merely on mixed patient groups, COPD patients or patients after cardiac surgery. Therefore, the best weaning strategy for stroke patients remains to be determined. METHODS: Here, we designed a prospective randomized controlled study comparing adaptive support ventilation (ASV), a continuous weaning strategy, with biphasic positive airway pressure (BIPAP) in combination with spontaneous breathing trials, a discontinuous technique, in the treatment of stroke patients. The primary endpoint was the duration of the weaning process. RESULTS: Only the 40 (out of 54) patients failing in an initial spontaneous breathing trial (T-piece test) were included into the study; the failure proportion is considerably larger compared to previous studies. Eligible patients were pseudo-randomly assigned to one of the two weaning groups. Both groups did not differ regarding age, gender, and severity of stroke. The results showed that the median weaning duration was 10.7 days (±SD 7.0) in the discontinuous weaning group, and 8 days (±SD 4.5) in the continuous weaning group (p < 0.05). CONCLUSIONS: To the best of our knowledge, this is the first clinical study to show that continuous weaning is significantly more effective compared to discontinuous weaning in mechanically ventilated stroke patients. We suppose that the reason for the superiority of continuous weaning using ASV as well as the bad performance of our patients in the 2 h T-piece test is caused by the patients' compliance. Compared to patients on surgical and medical ICUs, neurological patients more often suffer from reduced vigilance, lack of adverse-effects reflexes, dysphagia, and cerebral dysfunction. Therefore, stroke patients may profit from a more gradual withdrawal of weaning.


Assuntos
Respiração Artificial , Acidente Vascular Cerebral/terapia , Desmame do Respirador , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Unidades de Terapia Intensiva , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Tempo , Resultado do Tratamento , Desmame do Respirador/métodos
6.
Europace ; 16(3): 341-6, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24072443

RESUMO

AIMS: Phased radiofrequency (RF) ablation for atrial fibrillation is associated with an increased number of silent cerebral lesions on magnetic resonance imaging and cerebral microembolic signals (MESs) on transcranial Doppler ultrasound imaging compared with irrigated RF. The increased rate of embolic events may be due to a specific electrical interference of ablation electrodes attributed to the catheter design. The purpose of this study was to elucidate the effect of deactivating the culprit electrodes on cerebral MESs. METHODS AND RESULTS: Twenty-nine consecutive patients (60 ± 11 years, 10 female) underwent their first pulmonary vein isolation using phased RF energy. Electrode pairs 1 or 5 were deactivated to avoid electrical interference between electrodes 1 and 10 ('modified'). Detection of MESs by transcranial Doppler ultrasound was performed throughout the procedure to assess cerebral microembolism. Results were compared with the numbers of MESs in 31 patients ablated using all available electrodes ('conventional') and to 30 patients undergoing irrigated RF ablation of a previous randomized study. Ablation with 'modified' phased RF was associated with a marked decrease in MESs when compared with 'conventional' phased RF (566 ± 332 vs. 1530 ± 980; P < 0.001). This difference was mainly triggered by the reduction of MES during delivery of phased RF energy, resulting in MES numbers comparable to irrigated RF ablation (646 ± 449; P = 0.7). Total procedure duration as well as time of RF delivery was comparable between phased RF groups. Both times, however, were significantly shorter compared with the irrigated RF group (123 ± 28 vs. 195 ± 38; 15 ± 4 vs. 30 ± 9; P < 0.001, respectively). CONCLUSION: Pulmonary vein isolation with 'modified' phased RF is associated with a decreased number of cerebral microembolism especially during the delivery of ablation impulses, supporting the significance of electrical interference between ablation electrodes 1 and 10. Deactivation of electrode pairs 1 or 5 might increase the safety of this approach without an increase in procedure duration or RF delivery time.


Assuntos
Fibrilação Atrial/complicações , Fibrilação Atrial/cirurgia , Ablação por Cateter/efeitos adversos , Ablação por Cateter/métodos , Embolia Intracraniana/etiologia , Embolia Intracraniana/prevenção & controle , Veias Pulmonares/cirurgia , Fibrilação Atrial/diagnóstico , Feminino , Humanos , Embolia Intracraniana/diagnóstico , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
7.
Sci Transl Med ; 16(740): eade8560, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38536936

RESUMO

One of the biggest challenges in managing multiple sclerosis is the heterogeneity of clinical manifestations and progression trajectories. It still remains to be elucidated whether this heterogeneity is reflected by discrete immune signatures in the blood as a surrogate of disease pathophysiology. Accordingly, individualized treatment selection based on immunobiological principles is still not feasible. Using two independent multicentric longitudinal cohorts of patients with early multiple sclerosis (n = 309 discovery and n = 232 validation), we were able to identify three distinct peripheral blood immunological endophenotypes by a combination of high-dimensional flow cytometry and serum proteomics, followed by unsupervised clustering. Longitudinal clinical and paraclinical follow-up data collected for the cohorts revealed that these endophenotypes were associated with disease trajectories of inflammation versus early structural damage. Investigating the capacity of immunotherapies to normalize endophenotype-specific immune signatures revealed discrete effect sizes as illustrated by the limited effect of interferon-ß on endophenotype 3-related immune signatures. Accordingly, patients who fell into endophenotype 3 subsequently treated with interferon-ß exhibited higher disease progression and MRI activity over a 4-year follow-up compared with treatment with other therapies. We therefore propose that ascertaining a patient's blood immune signature before immunomodulatory treatment initiation may facilitate prediction of clinical disease trajectories and enable personalized treatment decisions based on pathobiological principles.


Assuntos
Esclerose Múltipla , Humanos , Esclerose Múltipla/genética , Esclerose Múltipla/tratamento farmacológico , Endofenótipos , Interferon beta/uso terapêutico
8.
Hum Brain Mapp ; 34(12): 3333-46, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22815223

RESUMO

Individual differences in executive functioning and brain morphology are considerable. In this study, we investigated their interrelation in a large sample of healthy older individuals. Digit span, trail-making, and Stroop tasks were used to assess different executive subfunctions in 367 nondemented community-dwelling individuals (50-81 years). Task performance was analyzed relative to brain structure using voxel-based morphometry, corrected for age and sex. Improved task performance was associated with increased local gray matter volume in task-specific patterns that showed partial, but not complete overlap with known task-specific functional imaging patterns. While all three tasks showed associations with prefrontal gray matter volume as expected for executive functioning, the strongest overlap between the three tasks was found in insular cortex, suggesting that it has a previously underestimated role for executive functions. The association between the insular cortex and executive functioning was corroborated using stereological region-of-interest measurement of insular volume in a subgroup of 93 subjects. Quantitatively, the volume of the single most strongly related region explained 2.4 ± 1.1% of the variance in executive performance over and above the variance explained by age, which amounted to 7.4 ± 4.1%. The age-independent peak associations between executive performance and gray matter described here occurred in regions that were also strongly affected by age-related gray matter atrophy, consistent with the hypothesis that age-related regional brain volume loss and age-related cognitive changes are linked.


Assuntos
Envelhecimento , Mapeamento Encefálico , Encéfalo/anatomia & histologia , Encéfalo/fisiologia , Função Executiva/fisiologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Alemanha , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Testes Neuropsicológicos , Fatores Sexuais , Técnicas Estereotáxicas
9.
Cortex ; 151: 15-29, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35378419

RESUMO

Apraxia of speech is a motor speech disorder that occurs after lesions to the left cerebral hemisphere, most often concomitant with aphasia. It requires specific approaches in the study of its physiological and neuroanatomical basis and special expertise in clinical care. Knowing its prevalence in patients with aphasia after stroke is therefore relevant for planning specific resources in clinical research and in health care provision. Systematic studies of the frequency of this condition are lacking. We examined the frequency of apraxia of speech in a representative sample of 156 patients with chronic post-stroke aphasia. Three experts classified the patients' speech by best-practice auditory-perceptual methods. Bayesian hierarchical models were fitted to obtain probability distributions for prevalence estimates. A prior distribution was calculated in two steps, including Bayesian models for published frequency data (step 1) and prevalence estimates from experienced clinicians (step 2). Separate models were fitted for different severity ranges. Overall, a prevalence rate of .44 [.30, .58] was obtained. When only moderate and severe cases were taken into account, the rate was .35 [.23, .49]. After a further restriction to only severe impairment, prevalence dropped to .22 [.12, .34]. Patients identified with apraxia of speech had suffered more severe strokes according to clinical criteria and had more severe aphasias. The presence of apraxia of speech was predicted by the articulation/prosody and syntax rating scales of the Aachen Aphasia Test. Lower prevalence estimates published earlier are probably biased by low sensitivity of assessment instruments for mild speech impairment.


Assuntos
Afasia , Apraxias , Acidente Vascular Cerebral , Afasia/complicações , Afasia/etiologia , Apraxias/epidemiologia , Teorema de Bayes , Humanos , Prevalência , Fala , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/epidemiologia
10.
Mult Scler ; 17(9): 1060-6, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21561958

RESUMO

BACKGROUND: The objective of this study was to address the differences in onset and disease progression between familial and sporadic multiple sclerosis (MS) and the association within sibling pairs. METHODS: Ninety-eight siblings and their controls were included from a database of 763 sporadic MS-patients, randomly pair-matched for age, gender, clinical course, disease duration and treatment. Sixty-eight available siblings completed a prospective six-year follow-up. Outcome parameters included baseline Expanded Disability Status Scale (EDSS), age at onset, mono- or multifocal onset, disease progression and conversion to secondary progression of initially relapsing-remitting MS. For statistical analyses Wilcoxon's signed-rank statistics for categorical differences, t-statistics for continuous variables, McNemar's test for relative frequencies of categories, intra-class correlations for within sibling-pair associations, or Kaplan-Meier analysis for survival analyses were used; all two-sided at the 5% level. RESULTS: Disease onset was slightly earlier (29.01 vs. 29.44 years, p = 0.0492) and multifocal onset significantly more often (p = 0.0052) in familial than in sporadic MS. Notably, a substantial within sibling-pair correlation for disease progression (rho = 0.40; p = 0.0062) as well as a higher risk for siblings than for controls to convert into secondary progression (0.545 vs. 0.227; p = 0.018) could be observed. CONCLUSIONS: Familial MS differs from sporadic cases with respect to age at onset, multifocal involvement as first clinical event, and conversion into secondary progression. The progression rate of one out of two affected siblings may act as a predictor for the other sib.


Assuntos
Progressão da Doença , Esclerose Múltipla/genética , Risco , Irmãos , Adulto , Idade de Início , Bases de Dados Factuais , Avaliação da Deficiência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
11.
Nat Rev Neurol ; 16(9): 493-505, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32641860

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic is concerning for patients with neuroimmunological diseases who are receiving immunotherapy. Uncertainty remains about whether immunotherapies increase the risk of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or increase the risk of severe disease and death upon infection. National and international societies have developed guidelines and statements, but consensus does not exist in several areas. In this Review, we attempt to clarify where consensus exists and where uncertainty remains to inform management approaches based on the first principles of neuroimmunology. We identified key questions that have been addressed in the literature and collated the recommendations to generate a consensus calculation in a Delphi-like approach to summarize the information. We summarize the international recommendations, discuss them in light of the first available data from patients with COVID-19 receiving immunotherapy and provide an overview of management approaches in the COVID-19 era. We stress the principles of medicine in general and neuroimmunology in particular because, although the risk of viral infection has become more relevant, most of the considerations apply to the general management of neurological immunotherapy. We also give special consideration to immunosuppressive treatment and cell-depleting therapies that might increase susceptibility to SARS-CoV-2 infection but reduce the risk of severe COVID-19.


Assuntos
Betacoronavirus , Consenso , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/terapia , Imunoterapia/normas , Neuroimunomodulação/imunologia , Pneumonia Viral/imunologia , Pneumonia Viral/terapia , COVID-19 , Humanos , Fatores Imunológicos/farmacologia , Fatores Imunológicos/uso terapêutico , Imunossupressores/farmacologia , Imunossupressores/uso terapêutico , Imunoterapia/métodos , Neuroimunomodulação/efeitos dos fármacos , Pandemias , SARS-CoV-2
12.
Front Neurol ; 10: 591, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31244756

RESUMO

Besides being affected by the rare and severe primary angiitis of the central nervous system (PACNS) the nervous system is also affected by primary systemic vasculitides (PSV). In contrast to PACNS, PSV affect not only the central but also the peripheral nervous system, resulting in a large array of potential symptoms. Given the high burden of disease, difficulties in distinguishing between differential diagnoses, and incomplete pathophysiological insights, there is an urgent need for additional precise diagnostic tools to enable an earlier diagnosis and initiation of effective treatments. Methods available to date, such as inflammatory markers, antibodies, cerebrospinal fluid (CSF) analysis, imaging, and biopsy, turn out to be insufficient to meet all current challenges. We highlight the use of biomarkers as an approach to extend current knowledge and, ultimately, improve patient management. Biomarkers are considered to be useful for disease diagnosis and monitoring, for predicting response to treatment, and for prognosis in clinical practice, as well as for establishing outcome parameters in clinical trials. In this article, we review the recent literature on biomarkers which have been applied in the context of different types of nervous system vasculitides including PACNS, giant-cell arteritis, Takayasu's arteritis, polyarteritis nodosa, ANCA (anti-neutrophil cytoplasm antibody)-associated vasculitides, cryoglobulinemic vasculitis, IgA vasculitis, and Behçet's disease. Overall, the majority of biomarkers is not specific for vasculitides of the nervous system.

13.
Ann Clin Transl Neurol ; 6(12): 2586-2594, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31682087

RESUMO

Allelic variants of genes encoding for the Fc gamma receptors IIIA and IIA have been associated with the clinical response to cell-depleting antibodies in lymphoma patients. Here, we tested the hypothesis that FCGR3A and FCGR2A high-affinity polymorphisms predict clinical outcomes to alemtuzumab therapy in 85 patients with relapsing-remitting multiple sclerosis. No differences in clinical and MRI-based efficacy parameters, the development of severe infusion-associated reactions and secondary autoimmune diseases during a 2 year follow-up was observed based on FCGR3A or FCGR2A polymorphisms. This study does not support the use of FCGR genetic variants to predict clinical outcomes to alemtuzumab.


Assuntos
Alemtuzumab/farmacologia , Fatores Imunológicos/farmacologia , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Esclerose Múltipla Recidivante-Remitente/genética , Avaliação de Resultados em Cuidados de Saúde , Receptores de IgG/genética , Adolescente , Adulto , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
14.
Neuropsychopharmacology ; 31(11): 2552-64, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16880771

RESUMO

Endogenous dopamine plays a central role in salience coding during associative learning. Administration of the dopamine precursor levodopa enhances learning in healthy subjects and stroke patients. Because levodopa increases both phasic and tonic dopaminergic neurotransmission, the critical mechanism mediating the enhancement of learning is unresolved. We here probed how selective tonic dopaminergic stimulation affects associative learning. Forty healthy subjects were trained in a novel vocabulary of 45 concrete nouns over the course of 5 consecutive training days in a prospective, randomized, double-blind, placebo-controlled design. Subjects received the tonically stimulating dopamine-receptor agonist pergolide (0.1 mg) vs placebo 120 min before training on each training day. The dopamine agonist significantly impaired novel word learning compared to placebo. This learning decrement persisted up to the last follow-up 4 weeks post-training. Subjects treated with pergolide also showed restricted emotional responses compared to the PLACEBO group. The extent of 'flattened' affect with pergolide was related to the degree of learning inhibition. These findings suggest that tonic occupation of dopamine receptors impairs learning by competition with phasic dopamine signals. Thus, phasic signaling seems to be the critical mechanism by which dopamine enhances associative learning in healthy subjects and stroke patients.


Assuntos
Aprendizagem por Associação/efeitos dos fármacos , Agonistas de Dopamina/efeitos adversos , Deficiências da Aprendizagem/induzido quimicamente , Pergolida/efeitos adversos , Adulto , Afeto/efeitos dos fármacos , Análise de Variância , Pressão Sanguínea/efeitos dos fármacos , Método Duplo-Cego , Feminino , Humanos , Deficiências da Aprendizagem/fisiopatologia , Masculino , Testes Neuropsicológicos , Estudos Prospectivos , Escalas de Graduação Psiquiátrica/estatística & dados numéricos , Tempo de Reação/efeitos dos fármacos , Fatores de Tempo , Aprendizagem Verbal/efeitos dos fármacos
15.
J Neurol Sci ; 248(1-2): 42-7, 2006 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-16815467

RESUMO

d-Amphetamine coupled with behavioral training has been effective for improving functional recovery after stroke. d-amphetamine acts on multiple brain transmitter systems, but the recovery enhancing effect has been attributed to its noradrenergic actions. Another potent modulator of learning is dopamine, which may also enhance stroke recovery in humans. Based on data from previous studies of our group, we compared the learning enhancing effects of d-amphetamine with a more selective dopaminergic substance (levodopa) in identical protocols. Using a prospective, randomized, double-blind, placebo-controlled design, we had taught 60 male healthy subjects a miniature lexicon of 50 concrete nouns over the course of five consecutive training days using an associative learning principle. Subjects had received either d-amphetamine (0.25 mg/kg), levodopa/carbidopa (fixed dose of 100/25 mg), or placebo 90 min prior to training on each of the 5 days. Novel word learning was significantly enhanced in both the d-amphetamine and levodopa groups as compared to the placebo group. The learning superiority was maintained at the two re-assessments (1 week and 1 month post training). Both d-amphetamine and levodopa are thus potent drugs in enhancing learning in humans. We here discuss why the efficiency of both d-amphetamine and levodopa may be related to dopaminergic rather than noradrenergic actions.


Assuntos
Dopamina/fisiologia , Aprendizagem/fisiologia , Norepinefrina/fisiologia , Adrenérgicos/farmacologia , Adulto , Análise de Variância , Dextroanfetamina/farmacologia , Dopaminérgicos/farmacologia , Método Duplo-Cego , Humanos , Aprendizagem/efeitos dos fármacos , Levodopa/farmacologia , Masculino , Testes Neuropsicológicos , Fatores de Tempo
17.
PLoS One ; 11(10): e0163375, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27711139

RESUMO

Optic neuritis (ON) has detrimental effects on the transmission of neuronal signals generated at the earliest stages of visual information processing. The amount, as well as the speed of transmitted visual signals is impaired. Measurements of visual evoked potentials (VEP) are often implemented in clinical routine. However, the specificity of VEPs is limited because multiple cortical areas are involved in the generation of P1 potentials, including feedback signals from higher cortical areas. Here, we show that dichoptic metacontrast masking can be used to estimate the temporal delay caused by ON. A group of 15 patients with unilateral ON, nine of which had sufficient visual acuity and volunteered to participate, and a group of healthy control subjects (N = 8) were presented with flashes of gray disks to one eye and flashes of gray annuli to the corresponding retinal location of the other eye. By asking subjects to report the subjective visibility of the target (i.e. the disk) while varying the stimulus onset asynchrony (SOA) between disk and annulus, we obtained typical U-shaped masking functions. From these functions we inferred the critical SOAmax at which the mask (i.e. the annulus) optimally suppressed the visibility of the target. ON-associated transmission delay was estimated by comparing the SOAmax between conditions in which the disk had been presented to the affected and the mask to the other eye, and vice versa. SOAmax differed on average by 28 ms, suggesting a reduction in transmission speed in the affected eye. Compared to previously reported methods assessing perceptual consequences of altered neuronal transmission speed the presented method is more accurate as it is not limited by the observers' ability to judge subtle variations in perceived synchrony.


Assuntos
Potenciais Evocados Visuais , Neurite Óptica/fisiopatologia , Transmissão Sináptica , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Estimulação Luminosa , Acuidade Visual
18.
PLoS One ; 11(6): e0157886, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27327662

RESUMO

OBJECTIVE: We had the objective to determine the impact of clinical parameters and anticoagulation status on cerebral microembolic signals (MES) during pulmonary vein isolation (PVI) for atrial fibrillation (AF). BACKGROUND: Thromboembolism and stroke are the most feared complications of PVI. MES can help to evaluate embolic burden. It is unknown whether clinical parameters have an impact on embolic risk during PVI. METHODS: In this retrospective analysis we investigated the impact of clinical parameters, including the CHADS2- and CHA2DS2-VASc-score, pulmonary vein variants and echocardiographic parameters on MES rates in patients that underwent PVI using three different ablation approaches (radiofrequency ablation (iRF), pulmonary vein ablation catheter (PVAC) with deactivated electrode pair 1 or 5 (PVAC-red) or PVAC without deactivation (PVAC-all). RESULTS: 118 AF patients (61±12 years) were included between 2011 and 2013 (Median: 489 MES during PVI). Patients were more likely to have more MES (within 4th quartile) with the PVAC-all approach (60.7% vs. 25.0% (iRF) vs. 14.3% (PVAC-red) respectively (p<0.001). Patients with oral anticoagulation (OAC) pre-ablation were more likely to have lower MES-counts (1st-3rd quartile); (65.6% vs. 35.7%; p = 0.005). Additionally, patients with lower MES counts (1st-3rd quartile) had significantly higher INR values than those in the 4th quartile (1.78 vs. 1.09; p = 0.029). 2 patients developed a potentially thromboembolic event during the procedure. CONCLUSION: Clinical predictors of cerebral emboli and stroke do not correlate with cerebral embolic burden during PVI. Pre-ablation OAC and increased INR values correlate with decreased MES-rates. Therefore, it might be beneficial to perform PVI with pre-ablation anticoagulation even in low risk patients.


Assuntos
Anticoagulantes/uso terapêutico , Embolia Intracraniana/tratamento farmacológico , Embolia Intracraniana/cirurgia , Veias Pulmonares/cirurgia , Feminino , Humanos , Coeficiente Internacional Normatizado , Masculino , Pessoa de Meia-Idade , Prognóstico
19.
Restor Neurol Neurosci ; 33(2): 115-20, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25588456

RESUMO

PURPOSE: L-dopa has been shown to improve outcome of moderate-intensity language training after stroke in acute aphasia. Given the critical role of training intensity we probed the effect of l-dopa in combination with high-intensity language training in chronic post-stroke aphasia. METHODS: In this prospective, randomized, placebo-controlled, double-blind study, aphasia patients (>1 year post stroke) were administered 100/25 mg of l-dopa/carbidopa or placebo daily prior to four hours of language training for two weeks. Conditions were crossed-over after a wash-out period of 4 weeks. RESULTS: An a-priori planned interim analysis (n = 10) showed that naming performance and verbal communication improved significantly and persistently for at least 6 months in every patient, but l-dopa had no incremental effect to intensive training. CONCLUSION: High-intensity language training in chronic aphasia may take learning to a ceiling that precludes additive benefits from l-dopa. Effects of l-dopa on post-stroke recovery during less intense treatment in chronic aphasia remain to be evaluated.


Assuntos
Afasia/terapia , Terapia da Linguagem/métodos , Levodopa/uso terapêutico , Nootrópicos/uso terapêutico , Adulto , Idoso , Afasia/etiologia , Doença Crônica , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Testes de Linguagem , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Acidente Vascular Cerebral/complicações , Reabilitação do Acidente Vascular Cerebral , Resultado do Tratamento
20.
J Neurol Sci ; 357(1-2): 115-8, 2015 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-26187298

RESUMO

OBJECTIVE: Behr syndrome, first described in 1909 by the ophthalmologist Carl Behr, is a clinical entity characterised by a progressive optic atrophy, ataxia, pyramidal signs and mental retardation. Some reported cases have been found to carry mutations in the OPA1, OPA3 or C12ORF65 genes which are known causes of pure optic atrophy or optic atrophy complicated by movement disorder. METHODS: We present the long-term observation of two Turkish sisters with Behr syndrome. We performed neurophysiological, imaging and molecular genetic studies to identify the underlying genetic cause in our patients. RESULTS: Magnetic resonance imaging of the brain showed bilateral hypointense signals in the basal ganglia which prompted us to consider neurodegeneration with brain iron accumulation (NBIA) as a differential diagnosis. Molecular genetic studies revealed a homozygous mutation in the C19ORF12 gene which has been previously reported in patients with a subtype of NBIA, mitochondrial membrane protein-associated neurodegeneration (MPAN). CONCLUSION: We expand the spectrum of genetic causes of Behr syndrome. Genetic testing of patients presenting with Behr syndrome should include C19ORF12 mutation screening.


Assuntos
Ataxia/genética , Perda Auditiva/genética , Deficiência Intelectual/genética , Proteínas Mitocondriais/genética , Mutação , Atrofia Óptica/congênito , Espasmo/genética , Adulto , Ataxia/patologia , Gânglios da Base/patologia , Feminino , Perda Auditiva/patologia , Homozigoto , Humanos , Deficiência Intelectual/patologia , Imageamento por Ressonância Magnética , Neuroimagem , Atrofia Óptica/genética , Atrofia Óptica/patologia , Espasmo/patologia , Adulto Jovem
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