title: A multiparametric evaluation of regional brain damage in patients with primary progressive multiple sclerosis.
abstract: The purpose of this study is to define the topographical distribution of gray matter (GM) and white matter (WM) damage in patients with primary progressive multiple sclerosis (PPMS), using a multiparametric MR-based approach. Using a 3 Tesla scanner, dual-echo, 3D fast-field echo (FFE), and diffusion tensor (DT) MRI scans were acquired from 18 PPMS patients and 17 matched healthy volunteers. An optimized voxel-based (VB) analysis was used to investigate the patterns of regional GM density changes and to quantify GM and WM diffusivity alterations of the entire brain. In PPMS patients, GM atrophy was found in the thalami and the right insula, while mean diffusivity (MD) changes involved several cortical-subcortical structures in all cerebral lobes and the cerebellum. An overlap between decreased WM fractional anisotropy (FA) and increased WM MD was found in the corpus callosum, the cingulate gyrus, the left short temporal fibers, the right short frontal fibers, the optic radiations, and the middle cerebellar peduncles. Selective MD increase, not associated with FA decrease, was found in the internal capsules, the corticospinal tracts, the superior longitudinal fasciculi, the fronto-occipital fasciculi, and the right cerebral peduncle. A discrepancy was found between regional WM diffusivity changes and focal lesions because several areas had DT MRI abnormalities but did not harbor T2-visible lesions. Our study allowed to detect tissue damage in brain areas associated with motor and cognitive functions, which are known to be impaired in PPMS patients. Combining regional measures derived from different MR modalities may be a valuable tool to improve our understanding of PPMS pathophysiology.
authors.affiliation: Neuroimaging Research Unit, Scientific Institute and University Ospedale San Raffaele, Milan, Italy.
authors.forename: Antonia
authors.initials: A
authors.lastname: Ceccarelli
authors.forename: Maria A
authors.initials: MA
authors.lastname: Rocca
authors.forename: Paola
authors.initials: P
authors.lastname: Valsasina
authors.forename: Mariaemma
authors.initials: M
authors.lastname: Rodegher
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Pagani
authors.forename: Andrea
authors.initials: A
authors.lastname: Falini
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Comi
authors.forename: Massimo
authors.initials: M
authors.lastname: Filippi
mesh_terms: D000328:Adult; D000368:Aged; D001284:Atrophy / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D001921:Brain / Q000473:pathology* / Q000503:physiopathology; D001925:Brain Damage, Chronic / Q000473:pathology* / Q000503:physiopathology; D001931:Brain Mapping; D003072:Cognition Disorders / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D038524:Diffusion Magnetic Resonance Imaging; D004185:Disability Evaluation; D018450:Disease Progression; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009069:Movement Disorders / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D020528:Multiple Sclerosis, Chronic Progressive / Q000473:pathology* / Q000503:physiopathology; D009413:Nerve Fibers, Myelinated / Q000473:pathology; D009434:Neural Pathways / Q000473:pathology / Q000503:physiopathology; D011237:Predictive Value of Tests; D011379:Prognosis; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index