Lower urinary tract dysfunction (LUTD) is one of the most disabling non-neurological complications of multiple sclerosis(MS) and is a major contributor to impaired quality of life. Overall, neurological disability is frequently assumed to reflect the severity of urinary symptoms; however, its predictive value remains uncertain. This study aimed to evaluate the relationship between neurological disability, bladder-specific dysfunction, urinary incontinence severity, and quality of life in patients with MS, and to identify independent determinants of urinary symptom burden.

This cross-sectional study included 45 adults with a confirmed diagnosis of MS. Demographic characteristics, disease duration, MS subtype, Expanded Disability Status Scale (EDSS) scores, and the bladder subscore of the Functional Systems Score (FSS-bladder) were recorded. Urinary incontinence severity was assessed using the International Consultation on Incontinence Questionnaire–Short Form (ICIQ-SF), and incontinence-related quality of life was measured with the Incontinence Quality of Life Scale (I-QOL).
Group comparisons were performed using the Kruskal–Wallis test. Associations between clinical variables and urinary outcomes were evaluated using Spearman correlation analysis. Multivariable linear regression models were constructed to identify independent predictors of urinary incontinence severity and quality of life.
Ethical approval was obtained, and written informed consent was provided by all participants.

The median age of participants was 44.8 years, with a median disease duration of 12 years; 77.8% were female. Patients with progressive MS subtypes demonstrated higher disability scores and more severe urinary symptoms.
EDSS showed a moderate positive correlation with urinary incontinence severity (ρ = 0.414, p = 0.004) and bladder dysfunction (ρ = 0.418, p = 0.004), and a negative correlation with quality of life (ρ = −0.441, p = 0.002). However, in multivariable regression analysis, bladder dysfunction (FSS-bladder) emerged as the only independent predictor of both urinary incontinence severity (β = 5.143, 95% CI: 2.014–8.273, p < 0.001) and quality of life impairment (β = −18.022, 95% CI: −23.602 to −12.442, p < 0.001). Age showed a weak association with incontinence severity, whereas disease duration, MS subtype, and overall EDSS score were not independent predictors.
The overall pattern of correlations between neurological disability, bladder dysfunction, and urinary symptom measures is illustrated in Figure 1.

These findings suggest that bladder-specific neurological assessment may be more informative than global disability scores when evaluating urinary symptom burden in patients with MS. Although overall neurological disability correlates with urinary outcomes, it does not independently explain symptom burden when bladder dysfunction is taken into account.

Bladder dysfunction, rather than overall neurological disability, is the primary determinant of urinary incontinence severity and quality-of-life impairment in patients with multiple sclerosis. Routine assessment of bladder-specific dysfunction may therefore be essential for identifying patients at risk of severe urinary symptoms and guiding targeted management strategies.