Cognitive deficits in multiple sclerosis: correlations with T2 changes in normal appearing brain tissue
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.
Document Type: Research Article
Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital, Hvidovre, Denmark
Danish Multiple Sclerosis Center, Department of Neurology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
Danish Psychological Publishers, Virum, Denmark
Publication date: May 1, 2012