Prevalence of cognitive impairment (CI) in patients with multiple sclerosis (MS): a systematic review and meta-analysis

Caspian Journal of Internal Medicine 2024 (Summer); 15(3): 392-413 DOI: 10.22088/cjim.15.3.392 Review Article Mozhde Askari (MD) 1 Omid Mirmosayyeb (MD) 1 Fatemeh Fattahi (MD) 1 Hamed Ghoshouni (MD) 1 Elham Moases Ghaffary (MD) 1 Vahid Shaygannejad (MD) 1 Mahsa Ghajarzadeh (MD) 2, 3* 1. Isfahan Neurosciences Research Center, Isfahan University of Medical Sciences, Isfahan, Iran 2. Multiple Sclerosis Research Center, Neuroscience Institute, Tehran University of Medical Sciences, Tehran, Iran 3. Universal council of epidemiology (UCE), Universal Scientific Education and Research Network (USERN), Tehran, Iran * Correspondence: Mahsa Ghajarzadeh, Multiple Sclerosis Research Center, Neuroscience institute, Tehran University of Medical Sciences, Tehran, Iran. E-mail: Tel: +98 2166581560 Received: 23 May 2023 Revised: 10 Jul 2023 Accepted: 20 Aug 2023 Prevalence of cognitive impairment (CI) in patients with multiple sclerosis (MS): A systematic review and meta-analysis Abstract Background: One of the complications of multiple sclerosis (MS) is cognitive impairment (CI). The prevalence of CI is reported variously in previous studies. The goal of this systematic review and meta-analysis to estimate pooled prevalence of CI in patients with MS and also the prevalence of CI based on the type of applied test. Methods: Two independent researchers systematically searched PubMed, Scopus, EMBASE, Web of Science, and google scholar as well as gray literature (conference abstracts, references of the references) which were published before up January 2022. Results: We found 4089 articles by literature search, after deleting duplicates 3174 remained. Ninety articles remained for meta-analysis. The pooled prevalence of CI using all types of tests was 41% (95% CI: 38-44%) (I2=91.7%, p<0.001). The pooled prevalence of CI using BRB test was 39% (95%CI: 36-42%) (I2=89%, p<0.001). The pooled prevalence of CI using BICAMS was 44% (95%CI: 37-51%, I2=95.4%, p<0.001). The pooled prevalence of CI using MACFIMS was 44% (95% CI: 36-53%) (I2=89.3%, p<0.001). Conclusions: The pooled prevalence of cognitive impairment in patients with MS is estimated as 41%, so CI it should be considered by clinicians. Keywords: Multiple sclerosis, Cognitive impairment, Systematic review. Citation: Askari M, Mirmosayyeb O, Fattahi F, et al. Prevalence of cognitive impairment (CI) in patients with multiple sclerosis (MS): A systematic review and meta-analysis. Caspian J Intern Med 2024; 15(3): 392-413. Multiple sclerosis (MS), an autoimmune disease of central nervous system (CNS) has lots of physical and psychological complications (1, 2). Cognitive impairment (CI) is one of the disabling complications of MS affecting between 40-65% of patients with MS (4). It has negative impacts on daily activities, social functioning, employment, education continuation, and finally the total quality of life (5). CI could be detected from earlier stages and progress during the time (6). CI is more prominent and more domains of cognition are affected in patients with progressive form of the disease (7). There is heterogeneity regarding degree and scope of CI in MS while the most common deficit is slowing of information processing speed and learning/memory inefficiency (8). Different tests such as Paced Auditory Serial Addition Test (PASAT), Symbol Digit Modalities Test (SDMT), Brief Repeatable Battery (BRB), minimal assessment of cognitive function in multiple sclerosis (MACFIMS) or its brief form (BICAMS) are applied for cognitive assessment in patients with MS(9). Each test evaluates different aspects of cognition and has its own advantages and disadvantages. Up to now, lots of studies reported prevalence of cognitive impairment using different tests, but the pooled prevalence of CI based on different available tests are not present. So, we designed this systematic review and meta-analysis to estimate pooled prevalence of CI in patients with MS and also the prevalence of CI based on the type of applied test. © The Author(s) Publisher: Babol University of Medical Sciences Caspian Journal of Internal Medicine 2024 (Summer); 15(3): 392-413 Prevalence of CI in patients with MS Methods Study design: Systematic review, and meta-analysis. Two independent researchers systematically searched PubMed, Scopus, EMBASE, Web of Science, and Google scholar as well as gray literature (conference abstracts, references of the references) which were published before up January 2022. The search was done on January 1st 2022. The search terns was: (“Multiple Sclerosis” OR “MS” OR “Relapsing-Remitting Multiple Sclerosis” OR “Chronic Progressive Multiple Sclerosis” OR “demyelinating diseases” OR “demyelinating disorders” OR “autoimmune demyelinating disease" AND “Cognitive Behavior Therapy” OR “Cognitive Therapy” OR “Cognitive Behavior Therapy” OR “Cognitive Psychotherapy” OR “Cognitive Therapy” OR “Cognition Therapy” OR (cognitive* AND behavior* AND therapy*)). Inclusion criteria were: Cross-sectional studies, and articles which had been published in the English language were included. Studies which used only one of the cognitive tests. Exclusion criteria: Clinical trials, cohorts, case-reports, letters to the editors.Two independent researchers collected data regarding first author, country of origin, number of enrolled patients, mean age, applied test for CI evaluation, F/M ratio, mean EDSS, and the number with CI. 393 Risk of bias assessment: We evaluated the risk of potential bias using the Newcastle-Ottawa Scale (NOS) for Assessing the Quality adapted for cross sectional studies (10). Statistical analysis: All statistical analyses were performed using STATA (Version 14.0; Stata Corp LP, College Station, TX, USA). We used random effects model. To determine heterogeneity, Inconsistency (I2) was calculated. Results We found 4089 articles by literature search, after deleting duplicates 3174 remained. Ninety articles remained for meta-analysis (figure 1). The basic characteristics of included studies are summarized in table 1. The pooled prevalence of CI using all types of tests was 41% (95% CI: 38-44%) (I2=91.7%, p<0.001) (Figure 2). The pooled prevalence of CI using BRB test was 39% (95%CI: 36-42%) (I2=89%, p<0.001) (Figure 3). The pooled prevalence of CI using BICAMS was 44% (95%CI: 37-51%, I2=95.4%, Pm<0.001) (Figure 4). The pooled prevalence of CI using MACFIMS was 44% (95% CI: 36-53%) (I2=89.3%, p<0.001) (Figure5). The pooled prevalence of CI in female patients was 33% (95%CI: 29-37%, I2=88%, p<0.001) (Figure 6). The pooled prevalence of CI in male cases was 40% (95%CI: 36-44%) (I2=68.7%, p<0.001) (Figure 7). Figure 1. Flow diagram summarizing the selection of eligible studies Caspian Journal of Internal Medicine 2024 (Summer); 15(3): 392-413 Askari M, et al. 394 Table 1. Basic characteristics of included studies 10 NR 9 8 6 9 9 9 38.54 (10.94) 8 Quality assessment NR 9 CD Age (MEAN)/SD NR NR BRB NR NR BRB 49/33 (...truncated)