Organizational strategies in verbal fluency as a potential screening tool for Cognitive Impairment in individuals diagnosed with Multiple Sclerosis

Multiple sclerosis (MS) is the most common chronic disease of the central nervous system and one of the most frequent causes of non-traumatic neurological disability in young adults. Between 50-65% of patients with MS will develop cognitive impairment (CI), with verbal fluency (VF) tasks being one of the most sensitive measures for its detection. It is estimated that 40-64% of the population shows impaired performance. However, only a limited number of studies have investigated the underlying cognitive processes of these tasks, considering variables such as organisational strategies (switching and clustering) and execution time. The present study aims to analyse the efficacy of phonological verbal fluency (pVF) and semantic verbal fluency (sVF) tasks as a screening tool for CI in MS. It is an exploratory casecontrol study with 16 patients diagnosed with MS, 5 with CI and 11 without CI, following the STROBE checklist. The results reveal differences between groups for both VF tasks, especially in those with semantic restriction, in total word recall and in the use of organisational strategies. Additionally, greater sensitivity to CI is suggested during the first time interval (0-30sec) independently of the group. Process analysis revealed the relationship between total words evoked of pVF with language, and sVF with language and EF. In both tasks, the first time interval correlated with memory, language and EF. In organisational strategies of sVF, total clusters were related to EF, total switchings to attention, and clustering during the first time interval to memory and EF. No cognitive process predicted strategies in pVF.