title: Cognitive impairment and memory disorders in relapsing-remitting multiple sclerosis: the role of white matter, gray matter and hippocampus.
abstract: Cognitive disorders occur in up to 65 % of multiple sclerosis (MS) patients; they have been correlated with different MRI measures of brain tissue damage, whole and regional brain atrophy. The hippocampal involvement has been poorly investigated in cognitively impaired (CI) MS patients. The objective of this study is to analyze and compare brain tissue abnormalities, including hippocampal atrophy, in relapsing-remitting MS (RRMS) patients with and without cognitive deficits, and to investigate their role in determining cognitive impairment in MS. Forty-six RRMS patients [20 CI and 26 cognitively preserved (CP)] and 25 age, sex and education-matched healthy controls (HCs) underwent neuropsychological evaluation and 3-Tesla anatomical MRI. T2 lesion load (T2-LL) was computed with a semiautomatic method, gray matter volume and white matter volume were estimated using SIENAX. Hippocampal volume (HV) was obtained by manual segmentation. Brain tissues volumes were compared among groups and correlated with cognitive performances. Compared to HCs, RRMS patients had significant atrophy of WM, GM, left and right Hippocampus (p < 0.001). Compared to CP, CI RRMS patients showed higher T2-LL (p = 0.02) and WM atrophy (p = 0.01). In the whole RRMS group, several cognitive tests correlated with brain tissue abnormalities (T2-LL, WM and GM atrophy); only verbal memory performances correlated with left hippocampal atrophy. Our results emphasize the role of T2-LL and WM atrophy in determining clinically evident cognitive impairment in MS patients and provide evidence that GM and hippocampal atrophy occur in MS patients regardless of cognitive status.
authors.affiliation: Department of Medical, Surgical, Neurological, Metabolic and Aging Sciences, Second University of Naples, Naples, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Sacco
authors.forename: A
authors.initials: A
authors.lastname: Bisecco
authors.forename: D
authors.initials: D
authors.lastname: Corbo
authors.forename: M
authors.initials: M
authors.lastname: Della Corte
authors.forename: A
authors.initials: A
authors.lastname: d'Ambrosio
authors.forename: R
authors.initials: R
authors.lastname: Docimo
authors.forename: A
authors.initials: A
authors.lastname: Gallo
authors.forename: F
authors.initials: F
authors.lastname: Esposito
authors.forename: S
authors.initials: S
authors.lastname: Esposito
authors.forename: M
authors.initials: M
authors.lastname: Cirillo
authors.forename: L
authors.initials: L
authors.lastname: Lavorgna
authors.forename: G
authors.initials: G
authors.lastname: Tedeschi
authors.forename: S
authors.initials: S
authors.lastname: Bonavita
mesh_terms: D000293:Adolescent; D000328:Adult; D001284:Atrophy / Q000473:pathology; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000209:etiology*; D004185:Disability Evaluation; D005260:Female; D066128:Gray Matter / Q000473:pathology*; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000209:etiology*; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000150:complications*; D009483:Neuropsychological Tests; D012720:Severity of Illness Index; D066127:White Matter / Q000473:pathology*; D055815:Young Adult