Complex oral semantic verbal fluency in non-brain-damaged adults and individuals with multiple sclerosis and subjective anomia

Abstract

ABSTRACT Background: Many neurologic conditions, for example multiple sclerosis (MS), are associated with subtle communication and language difficulties. To detect such difficulties, there is a need for valid and reliable methods. While standard aphasia test batteries have been found insufficient, more complex language tasks are believed to be able to distinguish more subtle language difficulties from normal variation in communicative ability. Aims: The aim of this study was to: (1) explore the influence of demographic variables on the results of a novel complex oral semantic fluency task with multiple restrictions in non-brain-damaged (NBD) adults, (2) investigate the construct validity and reliability of the method, and (3) compare the results of NBD individuals and individuals with MS. Method and procedure: One hundred and ten NBD individuals performed the complex task and three standard fluency tasks with single restrictions. Regression analyses were run to assess the influence of demographic factors. Furthermore, 16 individuals with MS and subjective anomia performed the complex task and the results were compared with those for a matched group of NBD individuals. Outcome and results: Age and education influenced the NBD individuals’ scores on the complex task. The NBD individuals’ results on the complex task correlated with those on the three standard fluency tasks. Furthermore, the subgroup of 16 pair-matched NBD individuals produced statistically significantly more adequate responses in the complex task than the group of individuals with MS. However, on an individual level some of the participants with MS performed at level with, or even better than the pair-matched NBD individuals. Provision of scoring guidelines yielded high interrater-reliability. Conclusions: The results illustrate the challenge in attempts to provide formal measures of subtle language disorders. Still, the complex task is a promising assessment tool which may be a complement to existing standard word fluency tasks, although future studies are required to establish the validity and ability to detect subtle language difficulties in different clinical groups.