Affiliations: Department of Clinical Neurosciences, University of
Cambridge, Cambridge, UK | Centre for Clinical Brain Science, University of
Edinburgh, Edinburgh, UK | School of Philosophy, Psychology and Language
Sciences, University of Edinburgh, Edinburgh, UK
Note: [] Corresponding author: Peter Connick, Anne McLaren Laboratory for
Regenerative Medicine, MRC Centre for Stem Cell Biology and Regenerative
Medicine, West Forvie Building, Forvie Site, Robinson Way, Cambridge, CB2 0SZ,
UK. Tel.: +44 1223 763366; Fax: +44 1223 763350; E-mail: pc349@cam.ac.uk
Abstract: BACKGROUND: Progressive MS is associated with a high frequency
of cognitive impairment. However, it is not clear to what extent this reflects
global dysfunction, or independent deficits in specific functions. OBJECTIVE: To characterise patterns of cognitive impairment in progressive MS
on a multi-dimensional cognitive assessment tool well established in
neurodegenerative diseases. METHODS: Patients with secondary (SPMS; n=60) and primary progressive MS (PPMS; n=28) were assessed using the
Addenbrooke's Cognitive Examination-Revised (ACE-R) multi-dimensional cognitive
assessment scale. Independent dimensions of impairment and their relative
contribution to the overall burden of cognitive dysfunction were then
determined by factor analysis. RESULTS: Two independent dimensions of
impairment were seen: frontal-executive (attention, verbal fluency, recall) on
one hand, and language and visuospatial functions on the other. These accounted
for 55% and 45% respectively of the variance not explained by a global
influence (14.2% and 11.6% respectively of total variance). Isolated
language and visuospatial dysfunction was seen in both groups, whereas isolated
impairment in frontal-executive functions was underrepresented in SPMS (p=0.001) and not seen in PPMS patients (p=0.040). CONCLUSIONS: In addition to a prominent global influence on cognitive performance, patients with progressive MS commonly
exhibit language and visuospatial deficits. Evaluation of these abilities should therefore be included in clinical
assessment of cognition in progressive MS.
