This study aims to establish a link between urinary Sphingosine 1-Phosphate (S1P) levels and detrusor activity in multiple sclerosis (MS) patients. MS often involves urological symptoms, primarily overactive bladder. The gold standard for evaluation and treatment monitoring is invasive urodynamic testing. Preliminary research at Toulouse University Hospital suggests urinary S1P levels may be a potential biomarker for detrusor activity in MS. This study aims to confirm this potential biomarker's utility.

Inclusion Criteria:

• French residents enrolled in the social security system
• Patients diagnosed with multiple sclerosis (according to McDonald 2017 criteria), whether receiving treatment or not
• Patients scheduled for urodynamic assessment as part of their management

Exclusion criteria:

• Pregnant or lactating females
• Patients under legal guardianship
• Untreated urinary tract infection at the time of inclusion
• Known anatomical subvesical obstruction Known pelvic floor disorder Urothelial carcinoma Interstitial cystitis Augmentation cystoplasty

Patients diagnosed with multiple sclerosis