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1.
Stroke ; 55(4): 1086-1089, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38362812

RESUMO

BACKGROUND: Spreading depolarization describes a near-complete electrical discharge with altered local cerebral blood flow. It is described in association with acute and chronic diseases like hemorrhagic stroke or migraine. Moyamoya vasculopathy is a chronic, progressive cerebrovascular disorder leading to cerebral hypoperfusion, hemodynamically insufficient basal collateralization, and increased cortical microvascularization. METHODS: In a prospective case series, we monitored for spontaneous spreading depolarization activity by using intraoperative laser speckle imaging for real-time visualization and measurement of cortical perfusion and cerebrovascular reserve capacity during cerebral revascularization in 4 consecutive patients with moyamoya. RESULTS: Spontaneous spreading depolarization occurrence was documented in a patient with moyamoya before bypass grafting. Interestingly, this patient also exhibited a marked preoperative increase in angiographic collateral vessel formation. CONCLUSIONS: The spontaneous occurrence of SDs in moyamoya vasculopathy could potentially provide an explanation for localized cortical infarction and increased cortical microvascular density in these patients.


Assuntos
Revascularização Cerebral , Transtornos Cerebrovasculares , Doença de Moyamoya , Humanos , Doença de Moyamoya/diagnóstico por imagem , Doença de Moyamoya/cirurgia , Angiografia Cerebral , Circulação Cerebrovascular/fisiologia , Revascularização Cerebral/métodos , Doença Crônica
2.
Cereb Cortex ; 33(5): 2162-2173, 2023 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-35584784

RESUMO

Speech production relies on the interplay of different brain regions. Healthy aging leads to complex changes in speech processing and production. Here, we investigated how the whole-brain functional connectivity of healthy elderly individuals differs from that of young individuals. In total, 23 young (aged 24.6 ± 2.2 years) and 23 elderly (aged 64.1 ± 6.5 years) individuals performed a picture naming task during functional magnetic resonance imaging. We determined whole-brain functional connectivity matrices and used them to compute group averaged speech production networks. By including an emotionally neutral and an emotionally charged condition in the task, we characterized the speech production network during normal and emotionally challenged processing. Our data suggest that the speech production network of elderly healthy individuals is as efficient as that of young participants, but that it is more functionally segregated and more modularized. By determining key network regions, we showed that although complex network changes take place during healthy aging, the most important network regions remain stable. Furthermore, emotional distraction had a larger influence on the young group's network than on the elderly's. We demonstrated that, from the neural network perspective, elderly individuals have a higher capacity for emotion regulation based on their age-related network re-organization.


Assuntos
Envelhecimento , Fala , Idoso , Humanos , Fala/fisiologia , Envelhecimento/fisiologia , Encéfalo/fisiologia , Mapeamento Encefálico , Imageamento por Ressonância Magnética , Vias Neurais/fisiologia
3.
BMC Med ; 21(1): 496, 2023 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-38093292

RESUMO

BACKGROUND: Fetal alcohol syndrome (FAS) can result in cognitive dysfunction. Cognitive functions affected are subserved by few functional brain networks. Functional connectivity (FC) in these networks can be assessed with resting-state functional MRI (rs-fMRI). Alterations of FC have been reported in children and adolescents prenatally exposed to alcohol. Previous reports varied substantially regarding the exact nature of findings. The purpose of this study was to assess FC of cognition-related networks in young adults with FAS. METHODS: Cross-sectional rs-fMRI study in participants with FAS (n = 39, age: 20.9 ± 3.4 years) and healthy participants without prenatal alcohol exposure (n = 44, age: 22.2 ± 3.4 years). FC was calculated as correlation between cortical regions in ten cognition-related sub-networks. Subsequent modelling of overall FC was based on linear models comparing FC between FAS and controls. Results were subjected to a hierarchical statistical testing approach, first determining whether there is any alteration of FC in FAS in the full cognitive connectome, subsequently resolving these findings to the level of either FC within each network or between networks based on the Higher Criticism (HC) approach for detecting rare and weak effects in high-dimensional data. Finally, group differences in single connections were assessed using conventional multiple-comparison correction. In an additional exploratory analysis, dynamic FC states were assessed. RESULTS: Comparing FAS participants with controls, we observed altered FC of cognition-related brain regions globally, within 7 out of 10 networks, and between networks employing the HC statistic. This was most obvious in attention-related network components. Findings also spanned across subcomponents of the fronto-parietal control and default mode networks. None of the single FC alterations within these networks yielded statistical significance in the conventional high-resolution analysis. The exploratory time-resolved FC analysis did not show significant group differences of dynamic FC states. CONCLUSIONS: FC in cognition-related networks was altered in adults with FAS. Effects were widely distributed across networks, potentially reflecting the diversity of cognitive deficits in FAS. However, no altered single connections could be determined in the most detailed analysis level. Findings were pronounced in networks in line with attentional deficits previously reported.


Assuntos
Conectoma , Transtornos do Espectro Alcoólico Fetal , Efeitos Tardios da Exposição Pré-Natal , Gravidez , Adolescente , Adulto Jovem , Criança , Humanos , Feminino , Adulto , Transtornos do Espectro Alcoólico Fetal/diagnóstico por imagem , Estudos Transversais , Encéfalo/diagnóstico por imagem , Cognição , Imageamento por Ressonância Magnética/métodos
4.
Neuroimage ; 235: 118006, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-33819611

RESUMO

A wide homology between human and macaque striatum is often assumed as in both the striatum is involved in cognition, emotion and executive functions. However, differences in functional and structural organization between human and macaque striatum may reveal evolutionary divergence and shed light on human vulnerability to neuropsychiatric diseases. For instance, dopaminergic dysfunction of the human striatum is considered to be a pathophysiological underpinning of different disorders, such as Parkinson's disease (PD) and schizophrenia (SCZ). Previous investigations have found a wide similarity in structural connectivity of the striatum between human and macaque, leaving the cross-species comparison of its functional organization unknown. In this study, resting-state functional connectivity (RSFC) derived striatal parcels were compared based on their homologous cortico-striatal connectivity. The goal here was to identify striatal parcels whose connectivity is human-specific compared to macaque parcels. Functional parcellation revealed that the human striatum was split into dorsal, dorsomedial, and rostral caudate and ventral, central, and caudal putamen, while the macaque striatum was divided into dorsal, and rostral caudate and rostral, and caudal putamen. Cross-species comparison indicated dissimilar cortico-striatal RSFC of the topographically similar dorsal caudate. We probed clinical relevance of the striatal clusters by examining differences in their cortico-striatal RSFC and gray matter (GM) volume between patients (with PD and SCZ) and healthy controls. We found abnormal RSFC not only between dorsal caudate, but also between rostral caudate, ventral, central and caudal putamen and widespread cortical regions for both PD and SCZ patients. Also, we observed significant structural atrophy in rostral caudate, ventral and central putamen for both PD and SCZ while atrophy in the dorsal caudate was specific to PD. Taken together, our cross-species comparative results revealed shared and human-specific RSFC of different striatal clusters reinforcing the complex organization and function of the striatum. In addition, we provided a testable hypothesis that abnormalities in a region with human-specific connectivity, i.e., dorsal caudate, might be associated with neuropsychiatric disorders.


Assuntos
Núcleo Caudado/fisiologia , Córtex Cerebral/fisiologia , Conectoma , Rede Nervosa/fisiologia , Doença de Parkinson , Putamen/fisiologia , Esquizofrenia , Adulto , Idoso , Animais , Núcleo Caudado/diagnóstico por imagem , Córtex Cerebral/diagnóstico por imagem , Conectoma/métodos , Conjuntos de Dados como Assunto , Feminino , Humanos , Macaca , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Rede Nervosa/diagnóstico por imagem , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/patologia , Doença de Parkinson/fisiopatologia , Putamen/diagnóstico por imagem , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/patologia , Esquizofrenia/fisiopatologia , Especificidade da Espécie , Adulto Jovem
5.
Neuroradiology ; 63(12): 2073-2085, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34019112

RESUMO

PURPOSE: Parkinson's disease (PD) is primarily defined by motor symptoms and is associated with alterations of sensorimotor areas. Evidence for network changes of the sensorimotor network (SMN) in PD is inconsistent and a systematic evaluation of SMN in PD yet missing. We investigate functional connectivity changes of the SMN in PD, both, within the network, and to other large-scale connectivity networks. METHODS: Resting-state fMRI was assessed in 38 PD patients under long-term dopaminergic treatment and 43 matched healthy controls (HC). Independent component analysis (ICA) into 20 components was conducted and the SMN was identified within the resulting networks. Functional connectivity within the SMN was analyzed using a dual regression approach. Connectivity between the SMN and the other networks from group ICA was investigated with FSLNets. We investigated for functional connectivity changes between patients and controls as well as between medication states (OFF vs. ON) in PD and for correlations with clinical parameters. RESULTS: There was decreased functional connectivity within the SMN in left inferior parietal and primary somatosensory cortex in PD OFF. Across networks, connectivity between SMN and two motor networks as well as two visual networks was diminished in PD OFF. All connectivity decreases partially normalized in PD ON. CONCLUSION: PD is accompanied by functional connectivity losses of the SMN, both, within the network and in interaction to other networks. The connectivity changes in short- and long-range connections are probably related to impaired sensory integration for motor function in PD. SMN decoupling can be partially compensated by dopaminergic therapy.


Assuntos
Doença de Parkinson , Córtex Sensório-Motor , Mapeamento Encefálico , Humanos , Imageamento por Ressonância Magnética , Vias Neurais/diagnóstico por imagem , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/tratamento farmacológico , Córtex Sensório-Motor/diagnóstico por imagem
6.
Neural Plast ; 2021: 8840452, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34188676

RESUMO

Age-related hearing loss has been associated with increased recruitment of frontal brain areas during speech perception to compensate for the decline in auditory input. This additional recruitment may bind resources otherwise needed for understanding speech. However, it is unknown how increased demands on listening interact with increasing cognitive demands when processing speech in age-related hearing loss. The current study used a full-sentence working memory task manipulating demands on working memory and listening and studied untreated mild to moderate hard of hearing (n = 20) and normal-hearing age-matched participants (n = 19) with functional MRI. On the behavioral level, we found a significant interaction of memory load and listening condition; this was, however, similar for both groups. Under low, but not high memory load, listening condition significantly influenced task performance. Similarly, under easy but not difficult listening conditions, memory load had a significant effect on task performance. On the neural level, as measured by the BOLD response, we found increased responses under high compared to low memory load conditions in the left supramarginal gyrus, left middle frontal gyrus, and left supplementary motor cortex regardless of hearing ability. Furthermore, we found increased responses in the bilateral superior temporal gyri under easy compared to difficult listening conditions. We found no group differences nor interactions of group with memory load or listening condition. This suggests that memory load and listening condition interacted on a behavioral level, however, only the increased memory load was reflected in increased BOLD responses in frontal and parietal brain regions. Hence, when evaluating listening abilities in elderly participants, memory load should be considered as it might interfere with the assessed performance. We could not find any further evidence that BOLD responses for the different memory and listening conditions are affected by mild to moderate age-related hearing loss.


Assuntos
Esforço de Escuta/fisiologia , Memória de Curto Prazo/fisiologia , Presbiacusia/psicologia , Aprendizagem Verbal/fisiologia , Idoso , Mapeamento Encefálico , Cognição , Feminino , Lobo Frontal/fisiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Testes de Estado Mental e Demência , Pessoa de Meia-Idade , Testes Neuropsicológicos , Lobo Parietal/fisiologia
7.
Cereb Cortex ; 29(1): 383-396, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30418548

RESUMO

Akinesia, a cardinal symptom of Parkinson's disease, has been linked to abnormal activation in putamen and posterior medial frontal cortex (pMFC). However, little is known whether clinical severity of akinesia is linked to dysfunctional connectivity of these regions. Using a seed-based approach, we here investigated resting-state functional connectivity (RSFC) of putamen, pMFC and primary motor cortex (M1) in 60 patients with Parkinson's disease on regular medication and 72 healthy controls. We found that in patients putamen featured decreases of connectivity for a number of cortical and subcortical areas engaged in sensorimotor and cognitive processing. In contrast, the pMFC showed reduced connectivity with a more focal cortical network involved in higher-level motor-cognition. Finally, M1 featured a selective disruption of connectivity in a network specifically connected with M1. Correlating clinical impairment with connectivity changes revealed a relationship between akinesia and reduced RSFC between pMFC and left intraparietal lobule (IPL). Together, the present study demonstrated RSFC decreases in networks for motor initiation and execution in Parkinson's disease. Moreover, results suggest a relationship between pMFC-IPL decoupling and the manifestation of akinetic symptoms.


Assuntos
Imageamento por Ressonância Magnética/métodos , Córtex Motor/diagnóstico por imagem , Movimento/fisiologia , Rede Nervosa/diagnóstico por imagem , Doença de Parkinson/diagnóstico por imagem , Análise de Componente Principal/métodos , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Córtex Motor/fisiopatologia , Rede Nervosa/fisiopatologia , Doença de Parkinson/fisiopatologia
8.
Eur Radiol ; 28(12): 4949-4958, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29948072

RESUMO

OBJECTIVES: The pathogenesis leading to poor functional outcome after aneurysmal subarachnoid haemorrhage (aSAH) is multifactorial and not fully understood. We evaluated a machine learning approach based on easily determinable clinical and CT perfusion (CTP) features in the course of patient admission to predict the functional outcome 6 months after ictus. METHODS: Out of 630 consecutive subarachnoid haemorrhage patients (2008-2015), 147 (mean age 54.3, 66.7% women) were retrospectively included (Inclusion: aSAH, admission within 24 h of ictus, CTP within 24 h of admission, documented modified Rankin scale (mRS) grades after 6 months. Exclusion: occlusive therapy before first CTP, previous aSAH, CTP not evaluable). A random forests model with conditional inference trees was optimised and trained on sex, age, World Federation of Neurosurgical Societies (WFNS) and modified Fisher grades, aneurysm in anterior vs. posterior circulation, early external ventricular drainage (EVD), as well as MTT and Tmax maximum, mean, standard deviation (SD), range, 75th quartile and interquartile range to predict dichotomised mRS (≤ 2; > 2). Performance was assessed using the balanced accuracy over the training and validation folds using 20 repeats of 10-fold cross-validation. RESULTS: In the final model, using 200 trees and the synthetic minority oversampling technique, median balanced accuracy was 84.4% (SD 0.7) over the training folds and 70.9% (SD 1.2) over the validation folds. The five most important features were the modified Fisher grade, age, MTT range, WFNS and early EVD. CONCLUSIONS: A random forests model trained on easily determinable features in the course of patient admission can predict the functional outcome 6 months after aSAH with considerable accuracy. KEY POINTS: • Features determinable in the course of admission of a patient with aneurysmal subarachnoid haemorrhage (aSAH) can predict the functional outcome 6 months after the occurrence of aSAH. • The top five predictive features were the modified Fisher grade, age, the mean transit time (MTT) range from computed tomography perfusion (CTP), the WFNS grade and the early necessity for an external ventricular drainage (EVD). • The range between the minimum and the maximum MTT may prove to be a valuable biomarker for detrimental functional outcome.


Assuntos
Aneurisma Intracraniano , Hemorragia Subaracnóidea , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/fisiopatologia , Aprendizado de Máquina , Masculino , Pessoa de Meia-Idade , Admissão do Paciente/estatística & dados numéricos , Valor Preditivo dos Testes , Estudos Retrospectivos , Hemorragia Subaracnóidea/diagnóstico por imagem , Hemorragia Subaracnóidea/fisiopatologia
10.
Hum Brain Mapp ; 38(12): 5845-5858, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28876500

RESUMO

Previous whole-brain functional connectivity studies achieved successful classifications of patients and healthy controls but only offered limited specificity as to affected brain systems. Here, we examined whether the connectivity patterns of functional systems affected in schizophrenia (SCZ), Parkinson's disease (PD), or normal aging equally translate into high classification accuracies for these conditions. We compared classification performance between pre-defined networks for each group and, for any given network, between groups. Separate support vector machine classifications of 86 SCZ patients, 80 PD patients, and 95 older adults relative to their matched healthy/young controls, respectively, were performed on functional connectivity in 12 task-based, meta-analytically defined networks using 25 replications of a nested 10-fold cross-validation scheme. Classification performance of the various networks clearly differed between conditions, as those networks that best classified one disease were usually non-informative for the other. For SCZ, but not PD, emotion-processing, empathy, and cognitive action control networks distinguished patients most accurately from controls. For PD, but not SCZ, networks subserving autobiographical or semantic memory, motor execution, and theory-of-mind cognition yielded the best classifications. In contrast, young-old classification was excellent based on all networks and outperformed both clinical classifications. Our pattern-classification approach captured associations between clinical and developmental conditions and functional network integrity with a higher level of specificity than did previous whole-brain analyses. Taken together, our results support resting-state connectivity as a marker of functional dysregulation in specific networks known to be affected by SCZ and PD, while suggesting that aging affects network integrity in a more global way. Hum Brain Mapp 38:5845-5858, 2017. © 2017 Wiley Periodicals, Inc.


Assuntos
Envelhecimento/fisiologia , Encéfalo/fisiopatologia , Doença de Parkinson/fisiopatologia , Esquizofrenia/fisiopatologia , Adulto , Idoso , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Humanos , Imageamento por Ressonância Magnética , Processos Mentais/fisiologia , Metanálise como Assunto , Pessoa de Meia-Idade , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiopatologia , Testes Neuropsicológicos , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/tratamento farmacológico , Descanso , Esquizofrenia/diagnóstico por imagem , Esquizofrenia/tratamento farmacológico , Máquina de Vetores de Suporte , Adulto Jovem
11.
Cerebrovasc Dis ; 43(5-6): 272-282, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28319953

RESUMO

BACKGROUND: The invasiveness and risk of thromboembolic complications of catheter angiography underline the need for alternative imaging modalities in patients following intracranial aneurysm (IA) repair. However, the overall image quality of existing noninvasive imaging modalities, such as single-energy CT angiography (SE-CTA), compromises its value in this respect. OBJECTIVE: We prospectively investigated the value of a novel dual-energy CTA (DE-CTA) scanner and algorithm for assessing the degree of occlusion and parent vessel patency in patients following IA repair. METHODS: A prospective cohort of 17 patients underwent DE-CTA imaging following surgical or endovascular IA repair. This dataset was matched with an identical historical cohort of 17 patients, who underwent IA repair and SE-CTA imaging. Beam-hardening artifacts, as a measure for objective imaging quality were analyzed based on the volume of a prolate ellipsoid, whereas subjective imaging quality at the IA site and corresponding parent vessels was rated by 2 independent neuroradiologists on a scale from 4 (excellent, no artifacts) to 1 (poor, severe artifacts). RESULTS: Objective DE-CTA image quality was markedly higher, compared to SE-CTA in patients undergoing surgical (0.77 ± 0.23 vs. 10.91 ± 1.88 mL, respectively; p < 0.001) or endovascular (32.36 ± 10.62 vs. 107.63 ± 24.51 mL, respectively; p = 0.026) IA repair. Subjective image quality for DE-CTA was significantly improved compared to SE-CTA in the surgical group but not in the endovascular group. The calculated dose values for DE-CTA in our study remain markedly below the legally required radiation dose limits. CONCLUSION: The imaging quality of DE-CTA, especially for patients undergoing surgical IA repair, is distinctly superior, compared to SE-CTA imaging. Therefore, DE-CTA may serve as a noninvasive alternative for assessing the IA occlusion rate and parent vessel patency.


Assuntos
Angiografia Cerebral/métodos , Angiografia por Tomografia Computadorizada/métodos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/cirurgia , Tomografia Computadorizada Multidetectores/métodos , Adulto , Idoso , Algoritmos , Artefatos , Angiografia Cerebral/instrumentação , Circulação Cerebrovascular , Angiografia por Tomografia Computadorizada/instrumentação , Feminino , Humanos , Aneurisma Intracraniano/fisiopatologia , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada Multidetectores/instrumentação , Variações Dependentes do Observador , Valor Preditivo dos Testes , Estudos Prospectivos , Doses de Radiação , Exposição à Radiação , Interpretação de Imagem Radiográfica Assistida por Computador , Sistema de Registros , Reprodutibilidade dos Testes , Estudos Retrospectivos , Tomógrafos Computadorizados , Grau de Desobstrução Vascular
12.
Hum Brain Mapp ; 37(3): 1235-53, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26700444

RESUMO

A typical feature of Parkinson's disease (PD) is pathological activity in the subthalamic nucleus (STN). Here, we tested whether in patients with PD under dopaminergic treatment functional connectivity of the STN differs from healthy controls (HC) and whether some brain regions show (anti-) correlations between functional connectivity with STN and motor symptoms. We used functional magnetic resonance imaging to investigate whole-brain resting-state functional connectivity with STN in 54 patients with PD and 55 HC matched for age, gender, and within-scanner motion. Compared to HC, we found attenuated negative STN-coupling with Crus I of the right cerebellum and with right ventromedial prefrontal regions in patients with PD. Furthermore, we observed enhanced negative STN-coupling with bilateral intraparietal sulcus/superior parietal cortex, right sensorimotor, right premotor, and left visual cortex compared to HC. Finally, we found a decline in positive STN-coupling with the left insula related to severity of motor symptoms and a decline of inter-hemispheric functional connectivity between left and right STN with progression of PD-related motor symptoms. Motor symptom related uncoupling of the insula, a key region in the saliency network and for executive function, from the STN might be associated with well-known executive dysfunction in PD. Moreover, uncoupling between insula and STN might also induce an insufficient setting of thresholds for the discrimination between relevant and irrelevant salient environmental stimuli, explaining observations of disturbed response control in PD. In sum, motor symptoms in PD are associated with a reduced coupling between STN and a key region for executive function.


Assuntos
Doença de Parkinson/fisiopatologia , Núcleo Subtalâmico/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Mapeamento Encefálico , Cerebelo/fisiopatologia , Feminino , Movimentos da Cabeça , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Vias Neurais/fisiopatologia , Córtex Pré-Frontal/fisiopatologia , Descanso , Índice de Gravidade de Doença
13.
Hum Brain Mapp ; 36(5): 1951-62, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25627959

RESUMO

Over 90 percent of patients with Parkinson's disease experience speech-motor impairment, namely, hypokinetic dysarthria characterized by reduced pitch and loudness. Resting-state functional connectivity analysis of blood oxygen level-dependent functional magnetic resonance imaging is a useful measure of intrinsic neural functioning. We utilized resting-state functional connectivity modeling to analyze the intrinsic connectivity in patients with Parkinson's disease within a vocalization network defined by a previous meta-analysis of speech (Brown et al., 2009). Functional connectivity of this network was assessed in 56 patients with Parkinson's disease and 56 gender-, age-, and movement-matched healthy controls. We also had item 5 and 18 of the UPDRS, and the PDQ-39 Communication subscale available for correlation with the voice network connectivity strength in patients. The within-group analyses of connectivity patterns demonstrated a lack of subcortical-cortical connectivity in patients with Parkinson's disease. At the cortical level, we found robust (homotopic) interhemispheric connectivity but only inconsistent evidence for many intrahemispheric connections. When directly contrasted to the control group, we found a significant reduction of connections between the left thalamus and putamen, and cortical motor areas, as well as reduced right superior temporal gyrus connectivity. Furthermore, most symptom measures correlated with right putamen, left cerebellum, left superior temporal gyrus, right premotor, and left Rolandic operculum connectivity in the voice network. The results reflect the importance of (right) subcortical nodes and the superior temporal gyrus in Parkinson's disease, enhancing our understanding of the neurobiological underpinnings of vocalization impairment in Parkinson's disease.


Assuntos
Encéfalo/fisiopatologia , Doença de Parkinson/fisiopatologia , Voz , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Atividade Motora/fisiologia , Vias Neurais/fisiopatologia , Descanso , Índice de Gravidade de Doença , Voz/fisiologia
14.
Eur Arch Otorhinolaryngol ; 272(4): 829-833, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24414527

RESUMO

The objective of the study was to determine the temporal occurrence of cochlear obliteration following translabyrinthine vestibular schwannoma resection. A retrospective chart review, cross-sectional study, and sequential analysis of the time series were performed. The retrospective study included patients undergoing translabyrinthine resection for stage T1-T2 vestibular schwannoma from 2007 to 2010 without prior therapy and postoperative follow-up including MRI of the brain and the cerebellopontine angle. Already 3 months after surgery a radiographic labyrinthine change was observed in 66.7 %, a partial obstruction in 50 %, and an obstruction limited to the saccule in 16.7 %. Only 33.3 % of the patients showed an unchanged inner ear. In consideration of early cochlear obstruction after translabyrinthine vestibular schwannoma resection, temporary follow-up is necessary. Since the indications for cochlear implantation (CI) have been extended, especially concerning patients with single-side deafness, a simultaneous or early second-stage CI after tumour removal should be discussed.


Assuntos
Doenças Cocleares , Implante Coclear/métodos , Dissecação/efeitos adversos , Neuroma Acústico , Complicações Pós-Operatórias , Adulto , Idoso , Ângulo Cerebelopontino/patologia , Cóclea/diagnóstico por imagem , Doenças Cocleares/diagnóstico , Doenças Cocleares/etiologia , Doenças Cocleares/cirurgia , Estudos Transversais , Dissecação/métodos , Orelha Interna/diagnóstico por imagem , Orelha Interna/cirurgia , Feminino , Perda Auditiva/etiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neuroma Acústico/patologia , Neuroma Acústico/cirurgia , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/cirurgia , Radiografia , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento
15.
BMC Neurol ; 14: 247, 2014 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-25516429

RESUMO

BACKGROUND: Neuromyelitis optica (NMO) is a severely disabling inflammatory disorder of the central nervous system and is often misdiagnosed as multiple sclerosis (MS). There is increasing evidence that treatment options shown to be beneficial in MS, including interferon-ß (IFN-ß), are detrimental in NMO. CASE PRESENTATION: We here report the first Caucasian patient with aquaporin 4 (AQP4) antibody (NMO-IgG)-seropositive NMO presenting with a tumefactive brain lesion on treatment with IFN-ß. Disease started with relapsing optic neuritis and an episode of longitudinally extensive transverse myelitis (LETM) in the absence of any brain MRI lesions or cerebrospinal fluid-restricted oligoclonal bands. After initial misdiagnosis of multiple sclerosis (MS) the patient received subcutaneous IFN-ß1b and, subsequently, subcutaneous IFN-ß1a therapy for several years. Under this treatment, the patient showed persisting relapse activity and finally presented with a severe episode of subacute aphasia and right-sided hemiparesis due to a large T2 hyperintensive tumefactive lesion of the left brain hemisphere and a smaller T2 lesion on the right side. Despite rituximab therapy two further LETM episodes occurred, resulting in severe neurological deficits. Therapeutic blockade of the interleukin (IL)-6 signalling pathway by tocilizumab was initiated, followed by clinical and radiological stabilization. CONCLUSION: Our case (i) illustrates the relevance of correctly distinguishing NMO and MS since these disorders differ markedly in their responsiveness to immunomodulatory and -suppressive therapies; (ii) confirms and extends a previous report describing the development of tumefactive brain lesions under IFN-ß therapy in two Asian NMO patients; and (iii) suggests tocilizumab as a promising therapeutic alternative in highly active NMO disease courses.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Encéfalo/patologia , Interferon beta/efeitos adversos , Neuromielite Óptica/diagnóstico , Aquaporina 4/imunologia , Autoanticorpos/imunologia , Feminino , Humanos , Interferon beta/uso terapêutico , Interleucina-6/metabolismo , Imageamento por Ressonância Magnética/métodos , Pessoa de Meia-Idade , Esclerose Múltipla/diagnóstico , Mielite Transversa/diagnóstico , Neuromielite Óptica/tratamento farmacológico
16.
Clin Neuroradiol ; 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38842737

RESUMO

Many functional magnetic resonance imaging (fMRI) studies and presurgical mapping applications rely on mass-univariate inference with subsequent multiple comparison correction. Statistical results are frequently visualized as thresholded statistical maps. This approach has inherent limitations including the risk of drawing overly-selective conclusions based only on selective results passing such thresholds. This article gives an overview of both established and newly emerging scientific approaches to supplement such conventional analyses by incorporating information about subthreshold effects with the aim to improve interpretation of findings or leverage a wider array of information. Topics covered include neuroimaging data visualization, p-value histogram analysis and the related Higher Criticism approach for detecting rare and weak effects. Further examples from multivariate analyses and dedicated Bayesian approaches are provided.

18.
Muscle Nerve ; 48(6): 889-96, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23532987

RESUMO

INTRODUCTION: We investigated the utility of diffusion tensor imaging (DTI) for detecting neuropathic changes in proximal nerve segments in patients with peripheral neuropathy. METHODS: Twenty-one individuals with (n = 11) and without (n = 10) peripheral neuropathy underwent DTI of a defined sciatic nerve segment. Patients and controls were evaluated by clinical examination and nerve conduction studies at baseline and 6 months after the initial DTI scan. RESULTS: The mean fractional anisotropy (FA) value was significantly lower in sciatic nerves from patients with peripheral neuropathy as compared with controls. Sciatic nerve FA values correlated with clinical disability scores and electrophysiological parameters of axonal damage at baseline and 6 months after MRI scan. CONCLUSIONS: DTI-derived FA values are a sensitive measure to discriminate healthy from functionally impaired human sciatic nerve segments. DTI of proximal nerve segments may be useful for estimating the proximal axonal degeneration burden in patients with peripheral neuropathies.


Assuntos
Imagem de Tensor de Difusão , Doenças do Sistema Nervoso Periférico/diagnóstico , Doenças do Sistema Nervoso Periférico/fisiopatologia , Adulto , Idoso , Anisotropia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Condução Nervosa/fisiologia , Exame Neurológico , Curva ROC , Nervo Isquiático/patologia , Nervo Isquiático/fisiopatologia , Estatísticas não Paramétricas
19.
Neuroradiology ; 55(11): 1323-31, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24026709

RESUMO

INTRODUCTION: Dynamic perfusion computed tomography (PCT) has been established as a diagnostic instrument for the detection of vasospasm after subarachnoid hemorrhage (SAH). The purpose of this study was to assess the prognostic impact of PCT parameters after SAH on the long-term outcome of patients. METHODS: Three hundred twelve patients were retrospectively interrogated with a questionnaire 23.06 ± 14.33 months after spontaneous subarachnoid hemorrhage. The modified Rankin scale (mRS) was determined, respectively. Scheduled PCT data sets from the first days after ictus were available for all patients. RESULTS: The maximum mean transit time over several examinations per hemisphere (MTTPEAK) values were significantly correlated (p ≤ 0.001, r = 0.422) with the clinical long-term outcome (mRS). Corresponding to our linear regression analysis, MTTPEAK is the second most important regressor (behind clinical severity of the initial hemorrhage) for the prediction of long-term mRS. An MTTPEAK threshold of 3.98 s (identified by receiver operating characteristic analysis, area under the curve = 0.75) predicted an unfavorable long-term outcome (mRS ≥ 2) with a sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of 67.3, 74.3, 84.5, 52.1, and 69.6 %, respectively. CONCLUSION: The presented data corroborate the relevance of PCT data for the clinical long-term outcome of SAH patients. By identification of patients who are at risk for a bad outcome and may need escalation of therapy, risk-benefit analysis is supported.


Assuntos
Imagem de Perfusão/métodos , Imagem de Perfusão/estatística & dados numéricos , Hemorragia Subaracnóidea/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Feminino , Alemanha , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Prevalência , Reprodutibilidade dos Testes , Estudos Retrospectivos , Medição de Risco , Sensibilidade e Especificidade , Hemorragia Subaracnóidea/terapia , Resultado do Tratamento
20.
Neurosurg Rev ; 36(3): 487-91, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23568696

RESUMO

Approaches to ventrally located intramedullary lesions of the upper cervical spine can be extremely challenging. We present a custom-tailored, minimally invasive anterior approach to a ventrally located, intramedullary cavernous hemangioma with partial lateral corpectomy of C2, complete resection of the lesion and subsequent reconstruction. A 20-year-old woman presented with the history of progressive numbness of the left upper and lower extremities and some episodes of severe headaches was referred to magnetic resonance imaging: Here, an intramedullary lesion with typical radiological features for a cavernous malformation at the ventral surface of the spinal cord at the C2 level was detected. The surgical procedure was performed under general anesthesia and electrophysiological monitoring (somatosensory-evoked potentials (SEP), muscle motor-evoked potentials (MEP), and D-wave recording). Complete resection of the cavernous malformation was achieved and reconstruction of the cervical spine was performed using a custom-tailored cage. Intraoperative neuromonitoring during resection, revealed a transient MEP loss, but unchanged D-wave and SEP recordings indicated unchanged neurological outcome. Early clinical follow-up of the patient revealed no new neurological deficits. At 3-month follow-up, there was some improvement of the sensory function. This custom-tailored minimally invasive anterior approach to a ventrally located intramedullary cavernous malformation with partial C2-corpectomy describes a possible and successful approach to ventrally located intramedullary lesions of the upper cervical spinal cord. Additionally, the hereby-described approach is not related to cervical instability.


Assuntos
Hemangioma Cavernoso do Sistema Nervoso Central/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Procedimentos Neurocirúrgicos/métodos , Potencial Evocado Motor/fisiologia , Potenciais Somatossensoriais Evocados/fisiologia , Feminino , Hemangioma Cavernoso do Sistema Nervoso Central/patologia , Hematoma Epidural Espinal/etiologia , Hematoma Epidural Espinal/patologia , Humanos , Ligamentos Longitudinais/cirurgia , Imageamento por Ressonância Magnética , Monitorização Fisiológica , Coluna Vertebral/patologia , Coluna Vertebral/cirurgia , Resultado do Tratamento , Adulto Jovem
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