title: Structural connectivity influences brain activation during PVSAT in Multiple Sclerosis.
abstract: To assess the influence of white matter pathology on cortical reorganization, we probed the fronto-parietal attention network in Multiple Sclerosis (MS) patients by combining the Paced Visual Serial Addition Test (PVSAT) with fMRI-guided fiber tractography (FT). During the PVSAT, the control subjects activated the left inferior parietal lobule, superior temporal gyrus, precuneus, precentral gyrus, and medial and middle frontal gyri; while the precuneus and the inferior parietal lobule gyrus bilaterally, the left precentral and angular gyri and the right superior parietal lobule were activated in the MS group. At fMRI-guided FT, the superior longitudinal fasciculus (SLF) was the main white matter tract connecting areas active during the PVSAT. We then identified two subgroups of MS patients according to the SLF mean Fractional Anisotropy, used as indicator of integrity. The activations of the MS patients with a less damaged tract were in the left hemisphere, similarly to controls; while the patients with a more damaged SLF showed bilateral cortical activations. The MS subgroups, however, did not differ in PVSAT performance. This approach could be useful to investigate the relationship between brain structural and functional plastic changes and to identify different MRI endophenotypes related to the same level of cognitive impairment.
authors.affiliation: Department of Neurosciences, Ophthalmology and Genetics (DINOG), Via De Toni, 5-16132, Genoa, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Bonzano
authors.forename: Matteo
authors.initials: M
authors.lastname: Pardini
authors.forename: Gian Luigi
authors.initials: GL
authors.lastname: Mancardi
authors.forename: Matteo
authors.initials: M
authors.lastname: Pizzorno
authors.forename: Luca
authors.initials: L
authors.lastname: Roccatagliata
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009103:Multiple Sclerosis / Q000503:physiopathology*; D009434:Neural Pathways / Q000503:physiopathology*