Cognitive deficits in multiple sclerosis: correlations with T2 changes in normal appearing brain tissue

• Published in: Acta neurologica Scandinavica Vol. 125; no. 5; pp. 338 - 344
• Main Authors: Lund, H., Jønsson, A., Andresen, J., Rostrup, E., Paulson, O. B., Sørensen, P. S.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.05.2012; Blackwell
• Subjects: Adult; Biological and medical sciences; Brain; Brain - pathology; Brain - physiopathology; Cognition Disorders - etiology; Cognition Disorders - pathology; Cognition Disorders - physiopathology; Cognitive ability; cognitive impairment; Diffusion Magnetic Resonance Imaging - methods; Female; Humans; Intelligence; Investigative techniques, diagnostic techniques (general aspects); magnetic resonance imaging; Male; Medical sciences; Middle Aged; Multiple sclerosis; Multiple Sclerosis - complications; Multiple Sclerosis - pathology; Multiple Sclerosis - physiopathology; N.M.R; Nerve Fibers, Myelinated - pathology; Nervous system; Neurology; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Problem solving; Retrospective Studies; T2 estimates; Tissue; Nervous system diseases; Multiple sclerosis; magnetic resonance imaging; Cognitive disorder; Central nervous system disease; Central nervous system; cognitive impairment; Nuclear magnetic resonance imaging; T2 estimates; Inflammatory disease; Encephalon
• ISSN: 0001-6314; 1600-0404
• DOI: 10.1111/j.1600-0404.2011.01574.x

Objectives –  Although disease load in multiple sclerosis (MS) often is based on T2 lesion volumes, the changes in T2 of normal appearing brain tissue (NABT) are rarely considered. By means of magnetic resonance, (MR) we retrospectively investigated whether T2 changes in NABT explain part of the cognitive impairment seen in MS and constitute a supplement to traditional measurement of T2 lesion volume. Materials and Methods –  Fifty patients with clinically definite MS were included (38 women, 12 men). Patients were MR scanned, neuropsychologically tested, and evaluated clinically with the Kurtzke Expanded Disability Status Scale (EDSS) and the Multiple Sclerosis Impairment Scale (MSIS). Voxel‐wise T2 estimates and total T2 lesion volume were tested for correlations with eight cognitive domains, a general cognitive dysfunction factor (CDF), and the two clinical scales. Results –  We found distinct clusters of voxels with T2 estimates correlating with CDF, mental processing speed, complex motor speed, verbal fluency, and MSIS. A significant negative correlation was found between total lesion volume and CDF (r = −0.34, P = 0.02), verbal intelligence (r = −0.40, P = 0.005), mental processing speed (r = −0.34, P = 0.03), visual problem solving (r = −0.40, P = 0.01), and complex motor speed (r = −0.39, P = 0.01). No significant correlation was detected between total lesion load and the clinical measures EDSS and MSIS. Conclusion –  Our results suggest that even in the NABT MR detects changes likely to be associated with an underlying pathology and possibly contributes to the cognitive impairment in MS.