Search

Background: Multiple sclerosis (MS) is an important cause of acquired neurological disability in young adults, characterized by multicentric inflammation, demyelination, and axonal damage. Objective: The objective is to investigate white matter (WM) damage progression in a Brazilian MS patient cohort, using diffusion tensor imaging (DTI) post-processed by tract-based spatial statistics (TBSS). Methods: DTI scans were acquired from 76 MS patients and 37 sex-and-age matched controls. Patients were divided into three groups based on disease duration. DTI was performed along 30 non-collinear directions by using a 1.5T imager. For TBSS analysis, the WM skeleton was created, and a 5000 permutation-based inference with a threshold of p <.05 was used, to enable the identification of abnormalities in fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD). Results: Decreased FA and increased RD, MD, and AD were seen in patients compared to controls and a decreased FA and increased MD and RD were seen, predominantly after the first 5 years of disease, when compared between groups. Conclusion: Progressive WM deterioration is seen over time with a more prominent pattern after 5 years of disease onset, providing evidence that the early years might be a window to optimize treatment and prevent disability. [ABSTRACT FROM AUTHOR]

Purpose The objectives of this study were to determine if HIV-infected patients treated with highly active antiretroviral therapy (HAART), without dementia, suffer from longitudinal gray matter (GM) volume loss, changes in white matter (WM) integrity and deterioration in functional connectivity at rest, in an average interval of 30 months. Methods Clinically stable HIV-positive patients (on HAART, CD4 + T lymphocyte > 200 cells/μl, and viral loads <50 copies/μl) were recruited. None of them had HIV-associated dementia. Each patient underwent two scans, performed in a 1.5-T magnetic resonance imaging (MRI) scanner. FreeSurfer was used to perform cortical volumetric reconstruction and segmentation of GM structures. WM integrity was assessed using tract-based spatial statistics to post-process diffusion tensor imaging data, and FMRIB's Software Library tools were used to post-process resting-state functional magnetic resonance imaging (RS-fMRI). Results There were no significant differences in cortical thickness, deep GM volumes, or diffusivity parameters between the scans at the two time points. Five resting-state networks were identified in our patients. In the second MRI, HIV-positive patients presented increased areas of functional connectivity in visual pathways, frontoparietal and cerebellar networks, compared with the first MRI (considering p < 0.05). Conclusions RS-fMRI revealed potentially compensatory longitudinal alterations in the brains of HIV-positive patients, attempting to compensate for brain damage related to the infection. [ABSTRACT FROM AUTHOR]