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Objectives: To assess white matter abnormalities in Parkinson's disease (PD). Methods: A hundred and thirty-two patients with PD (mean age 60.93 years; average disease duration 7.8 years) and 137 healthy controls (HC; mean age 57.8 years) underwent the same MRI protocol. Patients were assessed by clinical scales and a complete neurological evaluation. We performed a TBSS analysis to compare patients and controls, and we divided patients into early PD, moderate PD, and severe PD and performed an ROI analysis using tractography. Results: With TBSS we found lower FA in patients in corpus callosum, internal and external capsule, corona radiata, thalamic radiation, sagittal stratum, cingulum and superior longitudinal fasciculus. Increased AD was found in the corpus callosum, fornix, corticospinal tract, superior cerebellar peduncle, cerebral peduncle, internal and external capsules, corona radiata, thalamic radiation and sagittal stratum and increased RD were seen in the corpus callosum, internal and external capsules, corona radiata, sagittal stratum, fornix, and cingulum. Regarding the ROIs, a GLM analysis showed abnormalities in all tracts, mainly in the severe group, when compared to HC, mild PD and moderate PD. Conclusions: Since major abnormalities were found in the severe PD group, we believe DTI analysis might not be the best tool to assess early alterations in PD, and probably, functional and other structural analysis might suit this purpose better. However it can be used to differentiate disease stages, and as a surrogate marker to assess disease progression, being an important measure that could be used in clinical trials. HIGHLIGHTS DTI is not the best tool to identify early PDDTI can differentiate disease stagesDTI analysis may be a useful marker for disease progression.
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INTRODUCTION: Our goal was to investigate the cortical thickness and subcortical volume in subjects with craniocervical dystonia and its subgroups. METHODS: We studied 49 subjects, 17 with cervical dystonia, 18 with blepharospasm or oromandibular dystonia, and 79 healthy controls. We performed a whole group analysis, followed by a subgroup analysis. We used Freesurfer software to measure cortical thickness, subcortical volume and to perform a primary exploratory analysis in the craniocervical dystonia group, complemented by a region of interest analysis. We also performed a secondary analysis, with data generated from Freesurfer for subgroups, corrected by false discovery rate. We then performed an exploratory generalized linear model with significant areas for the previous steps using clinical features as independent variables. RESULTS: The primary exploratory analysis demonstrated atrophy in visual processing regions in craniocervical dystonia. The secondary analysis demonstrated atrophy in motor, sensory, and visual regions in blepharospasm or oromandibular dystonia, as well as in limbic regions in cervical dystonia. Cervical dystonia patients also had greater cortical thickness than blepharospasm or oromandibular dystonia patients in frontal pole and medial orbitofrontal regions. Finally, we observed an association between precuneus, age of onset of dystonia and age at the MRI exam, in craniocervical dystonia; between motor and limbic regions and age at the exam, clinical score and time on botulinum toxin in cervical dystonia and sensory regions and age of onset and time on botulinum toxin in blepharospasm or oromandibular dystonia. CONCLUSIONS: We detected involvement of visual processing regions in craniocervical dystonia, and a pattern of involvement in cervical dystonia and blepharospasm or oromandibular dystonia, including motor, sensory and limbic areas. We also showed an association of cortical thickness atrophy and younger onset age, older age at the MRI exam, higher clinical score and an uncertain association with longer time on botulinum toxin.
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Torcicolo/patologia , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Neuropathological and neuroimaging studies in Huntington disease (HD) have suggested a role for the cerebellum. Our goal was to perform a detailed evaluation of cerebellar morphology. We performed the Unified HD rating scale (UHDRS) and Montreal cognitive assessment (MOCA) in 26 HD patients and 26 healthy controls. We created a two-sample test to analyze cerebellar gray matter (GM) differences between groups and another to correlate GM alterations with UHDRS and MOCA, corrected for age, expanded cytosine-adenine-guanine repeats, and disease duration using the spatially unbiased atlas template (SUIT)-SPM-toolbox which preserves anatomical detailing. We found increased GM density in the anterior cerebellum compared to controls. Higher GM density in the postero-superior lobe correlated with mood symptoms. Worse motor function and better cognitive function correlated with GM changes in the posterior cerebellum (false discovery rate (FDR) correction p < 0.05 and k > 100 voxels). In this detailed study of the in vivo cerebellar morphology in HD, we observed GM changes in regions involved in sensorimotor integration, motor planning, and emotional processing, supporting cerebellar involvement in the neuropathological process of HD.
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Cerebelo/diagnóstico por imagem , Substância Cinzenta/diagnóstico por imagem , Doença de Huntington/diagnóstico por imagem , Imageamento por Ressonância Magnética , Envelhecimento/patologia , Cerebelo/patologia , Progressão da Doença , Feminino , Substância Cinzenta/patologia , Humanos , Doença de Huntington/patologia , Doença de Huntington/fisiopatologia , Doença de Huntington/psicologia , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de DoençaRESUMO
BACKGROUND: Imaging studies have revealed widespread neurodegeneration in Parkinson's disease (PD), but only a few considered the issue of asymmetrical clinical presentations. OBJECTIVE: To investigate if the side of onset influences the pattern of gray matter (GM) atrophy in PD. METHODS: Sixty patients (57.87 ± 10.27 years) diagnosed with idiopathic PD according to the U.K. Brain Bank criteria, 26 with right-sided disease onset (RDO) and 34 with left-sided disease onset (LDO), were compared to 80 healthy controls (HC) (57.1 ± 9.47 years). We acquired T1-weighted images on a 3 T scanner. Images were processed and analyzed with VBM8 (SPM8/Dartel) on Matlab R2012b platform. Statistic assessments included a two-sample test (family-wise error p < 0.05) with extent threshold of 20 voxels. RESULTS: Compared to HC, LDO patients had GM atrophy in the insula, putamen, anterior cingulate, frontotemporal cortex, and right caudate, while the RDO group showed atrophy at the anterior cingulate, insula, frontotemporal, and occipital cortex. CONCLUSION: This study revealed widespread GM atrophy in PD, predominantly in the left hemisphere, regardless of the side of onset. Future investigations should also consider handedness and side of onset to better characterize cerebral involvement and its progression in PD.
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BACKGROUND: Dystonias are hyperkinetic movement disorders characterized by involuntary muscle contractions resulting in abnormal torsional movements and postures. Recent neuroimaging studies in idiopathic craniocervical dystonia (CCD) have uncovered the involvement of multiple areas, including cortical ones. Our goal was to evaluate white matter (WM) microstructure in subjects with CCD using diffusion tensor imaging (DTI) analysis. METHODS: We compared 40 patients with 40 healthy controls. Patients were then divided into subgroups: cervical dystonia, blepharospasm, blepharospasm + oromandibular dystonia, blepharospasm + oromandibular dystonia + cervical dystonia, using tract-based spatial statistics. We performed a region of interest-based analysis and tractography as confirmatory tests. RESULTS: There was no significant difference in the mean fractional anisotropy (FA) and mean diffusivity (MD) between the groups in any analysis. DISCUSSION: The lack of DTI changes in CCD suggests that the WM tracts are not primarily affected.
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This study aims to provide a brief anatomical review of the temporal stem and its white matter fiber tracts related to temporal lobe epilepsy (TLE) surgery, and review the tractography strategies to access these white matter fiber tracts using Diffusion Tensor Image (DTI) techniques. The pertinent literature about the temporal stem anatomy and function was reviewed. DTI techniques used at our neuroimaging facility were presented, as well as the tractography strategies to find the main white matter tracts coursing through the temporal stem. The knowledge of the temporal stem anatomy and the DTI techniques are important tools to analyze the white matter fiber tracts involved in TLE surgery. Such analysis is considered to be important for further evaluating the clinical role of TS and its preservation as well as to propose more selective approaches to TLE.
Este estudo tem por objetivo proporcionar uma breve revisão anatômica do tronco temporal e dos tratos de fibras de substância branca relacionados com a cirurgia da epilepsia do lobo temporal (ELT) e revisar as estratégias de tractografia para ter acesso a esses tratos de fibras de substância branca usando técnicas de imagem de tensor de difusão (ITD). A literatura pertinente sobre a anatomia do tronco temporal e sua função foi analisada. As técnicas de ITD usadas em nossas instalações de neuroimagem foram apresentadas, assim como as estratégias de tractografia para encontrar os principais tratos de substância branca que fazem trajeto através do tronco temporal. O conhecimento da anatomia do tronco temporal e as técnicas de ITD são ferramentas importantes para analisar os tratos de fibras de substância branca envol- vidos na cirurgia da ELT. Essa análise é considerada importante para melhor avaliar o papel clínico do tronco temporal e sua preservação, bem como para propor abordagens mais seletivas para a ELT.
Este estudio tiene por objetivo proporcionar una breve revisión anatómica del tronco temporal y de los tractos de fibras de sustancia blanca relacionados con la cirugía de la epilepsia del lóbulo temporal (ELT) y revisar las estrategias de tractografía para tener acceso a esos tractos de fibras de sustancia blanca usando técnicas de imagen de tensor de difusión (ITD). Fue analizada la literatura pertinente sobre la anatomía del tronco temporal y su función. Fueron presentadas las técnicas de ITD usadas en nuestras instalaciones de neuroimagen, así como las estrategias de tractografía para encontrar los principales tractos de sustancia blanca que hacen el trayecto a través del tronco temporal. El conocimiento de la anatomía del tronco temporal y las técnicas de ITD son herramientas importantes para analizar los tractos de fibras de sustancia blanca involucrados en la cirugía de ELT. Ese análisis es considerado importante para evaluar mejor el papel clínico del tronco temporal y su preservación, bien como para proponer abordajes más selectivos para la ELT.
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Humanos , Tonsila do Cerebelo , Anatomia , Epilepsia , Imageamento por Ressonância MagnéticaRESUMO
BACKGROUND: Recent studies have addressed the role of structures other than the basal ganglia in the pathophysiology of craniocervical dystonia (CCD). Neuroimaging studies have attempted to identify structural abnormalities in CCD but a clear pattern of alteration has not been established. We performed whole-brain evaluation using voxel-based morphometry (VBM) to identify patterns of gray matter (GM) changes in CCD. METHODS: We compared 27 patients with CCD matched in age and gender to 54 healthy controls. VBM was used to compare GM volumes. We created a two-sample t-test corrected for subjects' age, and we tested with a level of significance of p < 0.001 and false discovery rate (FDR) correction (p < 0.05). RESULTS: Voxel-based morphometry demonstrated significant reductions of GM using p < 0.001 in the cerebellar vermis IV/V, bilaterally in the superior frontal gyrus, precuneus, anterior cingulate and paracingulate, insular cortex, lingual gyrus, and calcarine fissure; in the left hemisphere in the supplementary motor area, inferior frontal gyrus, inferior parietal gyrus, temporal pole, supramarginal gyrus, rolandic operculum, hippocampus, middle occipital gyrus, cerebellar lobules IV/V, superior, and middle temporal gyri; in the right hemisphere, the middle cingulate and precentral gyrus. Our study did not report any significant result using the FDR correction. We also detected correlations between GM volume and age, disease duration, duration of botulinum toxin treatment, and the Marsden-Fahn dystonia scale scores. CONCLUSION: We detected large clusters of GM changes chiefly in structures primarily involved in sensorimotor integration, motor planning, visuospatial function, and emotional processing.