Association of cognitive impairment and lesion volumes in multiple sclerosis--a MRI study

Abstract

Cognitive impairment (CI) can be demonstrated in 40-65% of multiple sclerosis (MS) patients, sometimes starting from the early stages of the disease. The objective of this study was a community-based investigation of FLAIR-hyperintense lesion volumes (LV) and their association with CI in patients with relapsing remitting (RR) MS. The neurocognitive assessment was conducted with the brief cognitive screening instrument, MUSIC. Magnetic resonance imaging (MRI) scans were obtained with a 1.5 Tesla Sigma Magnetom MRI scanner. We conducted a stepwise multiple regression analysis to assess the relative contribution of the main clinical, demographic and MRI-variables in predicting cognitive impairment. We recruited 78 patients with RRMS. The mean MUSIC score was 20.6 ± 5.4. Forty five percent of patients (n = 35, mean score 15.1 ± 3.3) had CI and 55% (n = 43, mean score 24.4 ± 2.5) had no sign of CI. In the correlation analysis of the MUSIC subtests only the interference test correlated negatively with the LV (r = -0.23). Multivariate linear regression analysis using MUSIC as the dependent continuous variable revealed LV and disability severity as independent factors associated with MUSIC (p value of the regression model < 0.001; adjusted R-square = 0.11). The results of the present study suggest an association between white matter damage and CI in MS. We could demonstrate an association between attention difficulties and the LV in MS patients.

Trial registration: ClinicalTrials.gov Identifier: NCT01250665 and NCT01250678.

Keywords: Cognitive impairment; Lesion volume; MRI; Multiple sclerosis.