The correlation between Cognitive Impairment and severity of pathologic Fatigue in MS patients (PP-40)

Introduction: Multiple sclerosis (MS) is a demyelinating disease of the central nervous system. Fatigue and cognitive impairment are common and debilitating symptoms of MS that affect the patient's quality of life considerably. Due to the limited data about the relationship between pathological fatigue and cognitive impairment in multiple sclerosis patients, this study aimed to determine the relationship.

Methods and Materials: In this cross-sectional study, patients with a definitive diagnosis of multiple sclerosis of RRMS type were included. The exclusion criteria were severe depression, other neurological disorders, and progressive type of MS. Cognitive impairment is assisted with the Symbol Digit Modality Test (SDMT) and the Paced Auditory Serial Addition test (PASAT). In this study, the Comprehensive Fatigue Assessment Battrey for Multiple Sclerosis (CFAB-MS) is used to evaluate pathological fatigue and related factors. SPSS software version 27 was used for statistical evaluation.
 
Results: In this study, 123 MS patients are included. The average age of the patients was 34.12±8.61. In this investigation, the differences between patients with (impaired SDMT: 7, impaired PASAT: 18) or without (normal SDMT: 84, normal PASAT: 73) cognitive impairments in terms of age, gender, duration of illness, disability status based on EDSS, and pathological fatigue were not statistically significant (p-values<0.05). However, the pain index had a significant relationship with impaired SDMT(p=0.02), unlike impaired PASAT(p=0/21). Conclusion: According to the findings of this study, there is no clear relationship between cognitive impairment and fatigue in multiple sclerosis patients. In examining factors affecting fatigue, no correlation was found between cognitive performance and mobility problems, sleep problems, stress status, mood, anxiety, depression, nutrition, and the ability to manage the surrounding environment. However, patients with better cognitive performance in the field of visual information processing speed (SDMT test) reported a lower impact of pain in their lives.