The Relationship Between Cognitive Function, Syntax, and Severity of Dysarthria in Persian-Speaking Patients With Multiple Sclerosis Publisher



Miarkiani M ; Mehri A ; Jalaei S
Source: Journal of Modern Rehabilitation Published:2026

Abstract

Introduction: Multiple sclerosis (MS) is a degenerative disease affecting the central nervous system. Patients with MS experience several difficulties in the fields of speech, language, and cognitive abilities. This study aimed to investigate the relationship between cognitive functions, syntax, and the severity of dysarthria in Persian-speaking patients with relapsing-remitting multiple sclerosis (RRMS), as well as comparisons with healthy non-patient individuals. Materials and Methods: This cross-sectional study compared 31 patients diagnosed with RRMS to 31 healthy adults matched with the patient group based on age, gender, and education level. Participants were assessed using the montreal cognitive assessment (MoCA), as well as the syntax comprehension subtest from the bilingual aphasia test and the sentence production test. Additionally, the presence of dysarthria was evaluated through the Frenchay dysarthria assessment (FDA-2), and the dysarthria’s severity was determined using the visual analog scale (VAS) by three Speech and language pathologists based on the recorded speech samples. Results: The findings revealed a significant difference between MS patients and the control group (P≤0.05). Additionally, the results showed a significant correlation between dysarthria severity and both syntax comprehension (P=0.002, Cohen’s d=0.803) and syntax production (P=0.005, Cohen’s d=0.820), as well as the MoCA (P = 0.001, Cohen’s d = 0.579). Furthermore, significant correlations were also found between the MoCA and both syntax comprehension and syntax production within the patient group (P≤0.05). The data was analyzed by SPSS software, version 26. The difference between the two groups was calculated using the independent t-test, and the correlation between them was analyzed using the Spearman test at a significance level of P≤0.05. Conclusion: Syntactic challenges in MS patients might be linked to underlying cognitive impairments, and as the severity of dysarthria increases in patients, their syntactic problems also escalate. The results of this study can help speech and language pathologists in clinical evaluations and in providing comprehensive treatment plans for patients with MS. Copyright © 2026 Tehran University of Medical Sciences.