Cognitive function and quality of life in multiple sclerosis patients: a cross-sectional study

BACKGROUND: Nearly half of all patients diagnosed with multiple sclerosis (MS) will develop cognitive dysfunction. Studies highlighted from no/weak impact to a strong impact of cognitive impairment on quality of life (QoL). The aim of this study was to assess the impact of cognitive dysfunction on self-reported QoL in MS patients while considering key confounding factors. METHODS: Design: cross-sectional study. Inclusion criteria: MS patients of any disease subtype. Data collection: sociodemographic (age, gender, marital status, education level, and occupational activity) and clinical data (MS subtype, disease duration); MS disability (Expanded Disability Status Scale, EDSS); depression (Beck Depression Inventory); fatigue (Modified Fatigue Impact Scale); QoL (SF36 and MusiQoL); and neuropsychological performance (Brief Repeatable Battery of Neuropsychological Tests, BRB-N). Statistical analysis: multiple linear regressions (forward-stepwise selection). RESULTS: One hundred and twenty-four patients were enrolled. Performance on BRB-N subtests varied widely (6% to 70% abnormal). The BRB-N classified 37-78% of the patients as cognitively impaired, depending on the definition of cognitive impairment. No links were found between the MusiQoL index and cognitive subtests, whereas marital status, EDSS, and depression were found to be independent predictive factors. CONCLUSIONS: The present study demonstrated the weak and scarce association between cognitive impairment and QoL, when the key confounding factors were considered. These results need to be confirmed with larger samples and more accurate tests of cognitive function.