Lexical access changes in patients with multiple sclerosis: A two-year follow-up study

Abstract

The aim of the study was to analyze lexical access strategies in patients with multiple sclerosis (MS) and their changes over time. We studied lexical access strategies during semantic and phonemic verbal fluency tests and also confrontation naming in a 2-year prospective cohort of 45 MS patients and 20 healthy controls. At baseline, switching lexical access strategy (both in semantic and in phonemic verbal fluency tests) and confrontation naming were significantly impaired in MS patients compared with controls. After 2 years follow-up, switching score decreased, and cluster size increased over time in semantic verbal fluency tasks, suggesting a failure in the retrieval of lexical information rather than an impairment of the lexical pool. In conclusion, these findings underline the significant presence of lexical access problems in patients with MS and could point out their key role in the alterations of high-level communications abilities in MS.

Keywords:

• Multiple sclerosis
• Language
• Lexical access
• Switching
• Clustering

The authors would like to acknowledge the support of the European Union (J.M., 512146LSH–2003–1.2.2–2), the Spanish Ministry of Health (J.S., CM 05/00222; J.M., FIS PI052520; and P.V., FIS RD07/0060/0001), the Navarra Government (J.G. and J.M.), the Basque Country Government (N.V.M.), and the Fundación Uriach (P.V.). We also wish to thank the MS society of Navarra and the participants who kindly agreed to take part in this study. Disclosure: The authors have no conflict of interest.