Accumulation of cortical lesions in MS: relation with cognitive impairment.
BACKGROUND
Gray matter (GM) lesions are frequently found in multiple sclerosis (MS) and their in-vivo detection has been improved using new magnetic resonance imaging sequences, such as double inversion recovery (DIR). However, little is known about progression of GM lesions over time.


OBJECTIVE
To study the longitudinal behavior of GM lesions and to explore their relation to cognitive impairment in MS.


METHODS
DIR images were acquired from 13 MS patients and seven healthy controls at two time points with a median interval of 3 years. At follow-up, all subjects underwent cognitive testing. Lesions were classified as white matter, cortical or hippocampal lesions.


RESULTS
In patients, median cortical lesion number had increased from 18 to 26 at follow-up (P = 0.01), median white matter (WM) lesion number had increased from 56 to 65 (P = 0.02), and no significant increase over time was found for hippocampal lesions. Cortical lesion number at follow-up was significantly higher in secondary progressive (SP) than in relapsing-remitting patients. Significant relations were found between cortical and WM lesion number at follow-up on the one hand and visuospatial memory and processing speed on the other hand. Hippocampal lesion number was related to visuospatial memory.


CONCLUSIONS
Cortical lesions increase significantly over a 3-year time period, are most frequent in SP patients, and are associated with cognitive impairment.
Department of Radiology, MS Center Amsterdam, VU University Medical Center, The Netherlands. s.roosendaal@vumc.nl
S D
SD
Roosendaal
B
B
Moraal
P J W
PJ
Pouwels
H
H
Vrenken
J A
JA
Castelijns
F
F
Barkhof
J J G
JJ
Geurts
D000328:Adult; D002540:Cerebral Cortex / Q000473:pathology*; D003072:Cognition Disorders / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020528:Multiple Sclerosis, Chronic Progressive / Q000473:pathology*; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000473:pathology*; D009483:Neuropsychological Tests