ApoE4-positive multiple sclerosis patients are more likely to have cognitive impairment: a cross-sectional study.

BACKGROUND: Multiple sclerosis (MS) presents with a wide variety of symptoms, including cognitive dysfunction. Previous studies in terms of the possible function of the ApoE4 allele as a risk factor for cognitive dysfunction in MS patients were associated with conflicting results. The role of the ε4 isoform of apolipoprotein (ApoE4) was investigated in this study as a risk factor for cognitive dysfunction in MS patients. METHODS: Mildly disabled relapsing-remitting MS (RRMS) patients were involved in this study. The neurocognitive assessment is conducted by the Minimal Assessment of Cognitive Function in MS (MACFIMS) battery. After determining the genotype, patients were divided into two groups of ApoE4-positive and ApoE4-negative groups, and cognitive findings were compared. RESULTS: Seventy-one patients with a mean age of 31.43 ± 8.75 were involved in this study. Eleven out of 17 (64.70%) patients in the ApoE4-positive group had at least one impaired test, while this rate was 16 out of 54 (29.62%) in the ApoE4-negative group (p < 0.01). The rate of overall cognitive impairment (failure in ≥ 2 tests) was not statistically different between groups of the study (p = 0.75). Impairment in Paced Auditory Serial Addition Test (PASAT) task and also the mean score of Brief Visuospatial Memory Test-Revised (BVMT-R) tests were different between two groups (p = 0.01 and 0.02, respectively). CONCLUSION: MS ApoE4-positive patients are more likely to have at least one impaired cognitive test, but there is a need for more studies with larger sample sizes and based on MS-specific cognitive tests to confirm these findings.

The Expanded Disability Status Scale Score and Demographic Indexes Are Correlated with the Severity of Cognitive Impairment in Multiple Sclerosis Patients.

BACKGROUND AND PURPOSE: Cognitive impairment (CI) is a common symptom of multiple sclerosis (MS). Although demographic and clinical factors contribute to MS-dependent CI, previous findings have been inconsistent. This study aimed to identify the cognitive domains that are impaired in MS patients, and to determine the impacts of the Expanded Disability Status Scale (EDSS) score and other clinical and demographic factors on them domains. METHODS: This study enrolled 115 MS patients. Cognitive performance was assessed using the Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS) battery. CI severity was assessed based on the number of impaired tasks in the MACFIMS battery, with impairment in two or more tasks defined as CI cases. Correlation analysis was used to determine whether factors including current age, age at disease onset, EDSS score, disease duration, relapse rate, and education level affect the severity of CI. RESULTS: The scores on the Paced Auditory Serial Addition Test and Delis-Kaplan Executive Function System were the most and least affected, respectively. EDSS score (r=0.438, p<0.001), current age (r=0.393, p<0.001), and disease duration (r=0.486, p<0.001) were positively correlated with CI severity, whereas education level (r=-0.527, p<0.001) had a negative correlation with CI severity, and age at disease onset and relapse rate were not correlated with CI severity (r=0.150 and p=0.107, and r=0.052 and p=0.530, respectively). However, all variables (except EDSS score) significantly predicted CI severity in a multiple regression model (p<0.001, r=0.668). CONCLUSIONS: Information processing speed and working memory were the most commonly affected cognitive domains in the present MS patients. CI severity had strong positive correlations with current age, EDSS score, and disease duration, and a negative correlation with education level. The relapse rate and age at disease onset were not correlated with CI severity.