Author Of 1 Presentation
P0802 - Differences in Regional Cortical Thickness and Subcortical Volumes Among Cognitively Impaired and Unimpaired Multiple Sclerosis Patients (ID 829)
Abstract
Background
The Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) is a well-established neuropsychological battery to evaluate cognitive changes in patients with Multiple Sclerosis (MS). FreeSurfer has been used to assess neuroanatomical features, including cortical thickness and subcortical volume, as correlates of disease activity. The evaluation of cognitive performance, when combined with FreeSurfer analysis, may offer unique cross-sectional insight into the natural history of MS and the ways in which neurodegeneration interacts with cognition across different stages of disease.
Objectives
This study aims to take a cross-sectional view of a large MS patient cohort and study the relationship between cortical/subcortical measurements and cognitive function across various domains. Its objective is to compare the differences in cortical thickness and subcortical volume in subjects who are cognitively impaired and cognitively unimpaired.
Methods
163 patients with MS underwent both T1-weighted magnetic resonance imaging (MRI) and formal BICAMS testing within three months of one another. FreeSurfer was then used to analyze imaging data. BICAMS includes the Symbol Digit Modalities Test (SDMT), the California Verbal Learning Test (CVLT), and the Brief Visuospatial Memory Test (BVMT). Impairment was based upon published age-matched normative data. Patients had a mean disease duration of 10.5 +/- 7.3 years; mean Expanded Disability Status Scale (EDSS) of 1.3 +/- 1.6; mean age of 42.9 +/- 10.5 years. Multivariate regression analysis was used to compare cortical thickness and subcortical volume in impaired vs.unimpaired subjects.
Results
31, 15 and 38 patients were found to be impaired on SDMT, CVLT, and BVMT testing, respectively. Significant differences were found in multiple subcortical regions among impaired and unimpaired on SDMT (Thalamus; p=0.01) and BVMT (Left/Right Accumbens; p=0.001, p=0.02; Caudate; p=<0.001; Left Cerebellum; p=0.02; Left/Right Hippocampus; p=0.004, p=0.02; Left Pallidum; p=0.01; Left/Right Putamen; p=0.02, p=0.004; Right Amygdala; p=0.02; Right Thalamus; p=0.004). Impairment on SDMT was associated with differences in caudal anterior cingulate cortex (p= 0.001) and entorhinal cortex (p=0.003) and BVMT impairment was associated with thinning in temporal lobe regions (Right Bank of Superior Temporal Lobe; p=0.008; Right Fusiform; p=0.02). SDMT, CVLT, BVMT were all associated with differences in various occipital lobe regions. No significant differences were found when looking at the four anatomic lobes in their entirety.
Conclusions
Our results show associations between impaired performance on certain neuropsychological tests and regional cortical thinning and subcortical volume loss in what is the largest known cohort to date. These findings could shed light on unique and overlapping neuroanatomical substrates underlying different cognitive processes in MS.