A Study on Verbal Fluency of Persian Patients with Three Types of Multiple Sclerosis

Abstract

Background: Multiple sclerosis (MS) is an acquired autoimmune disease of the brain and spinal cord, resulting in the loss of control, vision, balance, and senses. Among the most important complications of MS in the course of the disease are speech disorders, especially dysarthria, as well as impairment of difficulty and language disorders. Objectives: Therefore, this research aimed to study the verbal fluency of Persian patients on three types of MS (Relapsing-Remitting, Primary Progressive, and Secondary Progressive). Methods: The descriptive-analytical approach was employed in this cross-sectional research. Since three types of MS were analyzed in this study, the samples collected using the convenience non-probability sampling technique from the MS patients in Rofeideh Rehabilitation Hospital in Tehran. Based on the inclusion criteria, 24 patients were put in each subgroup, and a total of 72 patients were selected. Besides, the mini-mental state examination (MMSE) was carried out in this research to study the cognitive conditions of the patients. The verbal fluency test has two subtests: semantic and phonological fluency. These two components were analyzed for analyzing lexical knowledge and flexibility. In the data analysis phase, the normal distribution of the data was examined by the Shapiro-Wilk test, and paired t-test, one-way analysis of variance, and Bonferroni non-parametric tests were used to compare the mean values of the variables and analyze the data. Results: Our findings revealed a mean switching and total verbal fluency of 11.6 (SD = 4.56) and 27.3 (SD = 7), respectively. The different forms of word switching and phonological fluency had no significant relationship with age and gender, but MMSE had a significant positive relationship with all of them (P < 0.05). The results from the analysis of variance and Bonferroni test also revealed no significant difference between the mean values on the SP and PP types of MS, but there was a significant difference between all mean values on the RR as well as the PP types (P < 0.05). However, the types of PP, SP, and RR did not significantly differ in word switching. Besides, phonological switching and verbal switching varied significantly in patients by academic degree (P < 0.001). Conclusions: The findings from this research revealed that the three types of MS differed significantly at least in lexical switching, phonological fluency, or semantic fluency.