Sara Yazdani - Ph.D. candidate,Linguistics department, Ferdowsi University of Mashhad, Mashhad, Iran

Background and Objective:Multiple sclerosis (MS)is a long-standing demyelinating neurological disease that caused by lesions in the brain and spinal cords. Regarding the extent and location of lesions in the Central Nervous System, MS patients might experience different types of symptoms such as difficulty walking, stress, fatigue, mood swings, and depression. Another problem for this population is cognitive impairment which causes difficulty in remembering events and names, attention, and multitasking. Despite these problems, MS patients might have problems with linguistic abilities such as syntax and maintaining complexity in their language structure. Therefore, the aim of this study was to assess the clausal density in the written language of individuals with MS.Materials and Methods: In this cross-sectional study, 30 patients (22 females and 8 males) with the definite diagnosis of relapsing-remitting MS were randomly selected from the patients referred to a private neurology clinic in Mashhad, Iran. The patients aged from 18 to 55 years (M=38.33, SD=9.15), full- time education degree from undergraduate to postgraduate degree (M=14.02, SD= 2.18), total disease duration from 1 year to 29 year (M=8.28, SD= 6.76). The patients recruited for this study had Expanded Disability Status Scale (EDSS) scores ranged from 0-4 (M=1.76, SD=1.05). Their age and education-matched control subjects comprised of 30 individuals chosen from patients’ relatives and family members. None of the participants had a history of drug and/or alcohol abuse, brain surgery, psychiatric disorder, and uncorrected visual or auditory problems. All of the participants were right-handed, Persian native speakers, originally born in Mashhad, Iran. The Boston Cookie Theft picture description test was used to evaluate the probable changes in syntactic sentence structures of MS patients. The participants were asked to write their description down. The written samples were analyzed for Total Number of T-units, the number of the main clause (NMC), and the number of the subordinate clause (NSC) scores.Findings: The results of the study showed that the patient scores (M=5.83, SD=2.73) were significantly lower(p-value=0.00, p < 0.05) than healthy controls score (M=8.7, SD=4.66). In other words, the patient group’s written samples were not syntactically complex in comparison to their healthy counterparts. Moreover, there was no significant difference(p-value=0.67, p > 0.05) between the groups on the number of the main clause.Nonetheless, the results also showed that the patient group (M=2.46, SD=2.04) used a significantly fewer number of subordinate clause (p-value=0.00, p < 0.05) compared to healthy controls (M=5, SD=3.33).Conclusion: The findings ofthis study revealed thatmultiple sclerosis can affect the language system. Therefore, it is necessary for clinician and rehabilitation service providers to consider language-related difficulties such as syntax structure and structural complexity in MS patients.

linguistics, syntax, main and subordinate clauses, multiple sclerosis, relapsing-remitting