title: Cognitive impairment in multiple sclerosis is associated to different patterns of gray matter atrophy according to clinical phenotype.
abstract: OBJECTIVE
  To investigate whether cognitive impairment in multiple sclerosis (MS) patients is associated to different patterns of gray matter (GM) atrophy and T2-visible lesion distribution according to the clinical phenotype.
  
  
  METHODS
  Twenty-two relapsing remitting (RR), 29 secondary progressive (SP), and 22 primary progressive (PP) MS patients, and 39 healthy controls underwent high-field structural magnetic resonance imaging and an extensive neuropsychological battery. Voxel-wise distribution of GM damage and T2-lesions was compared between cognitively impaired (CI) and cognitively preserved (CP) patients according to their clinical phenotype.
  
  
  RESULTS
  Thirty-nine MS patients were CI. In all MS groups, regional GM loss was correlated with cognitive impairment. Different patterns of regional distribution of GM atrophy and T2-visible lesions were found between CI vs. CP MS patients, according to their clinical phenotype. No areas were significantly more atrophied in CI SPMS vs. CI RRMS patients. Conversely, compared with CI PPMS, CI SPMS patients had a significant GM loss in several regions of the fronto-temporal lobes, the left hypothalamus and thalami. While in RRMS and SPMS patients there was a correspondence between presence of T2 visible lesions and GM atrophy in several areas, this was not the case in PPMS patients.
  
  
  CONCLUSIONS
  Distinct patterns of regional distribution of GM damage and T2-visible lesions are associated with cognitive impairment in MS patients with different clinical phenotypes. The correspondence between lesion formation and GM atrophy distribution varies in the different forms of MS.
authors.affiliation: Neuroimaging Research Unit, Institute of Experimental Neurology, Scientific Institute and University Ospedale San Raffaele, Milan, Italy.
authors.forename: Gianna
authors.initials: G
authors.lastname: Riccitelli
authors.forename: Maria A
authors.initials: MA
authors.lastname: Rocca
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Pagani
authors.forename: Maria E
authors.initials: ME
authors.lastname: Rodegher
authors.forename: Paolo
authors.initials: P
authors.lastname: Rossi
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 / Q000473:pathology; D001921:Brain / Q000473:pathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000209:etiology* / Q000473:pathology*; D003658:Decision Making, Computer-Assisted; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications*; D009483:Neuropsychological Tests; D010641:Phenotype; D012720:Severity of Illness Index; D013223:Statistics as Topic; D055815:Young Adult