Inclusion and Exclusion Criteria

Inclusion Criteria -At least 18 years old -Able to understand the patient information sheet -Written informed consent to take part and follow the requirements of the protocol For patients with MS: -Diagnosis according to the McDonald criteria -Having a score on the Kurtzke Expanded Disability Status Scale ≤ 6.5 -Free of relapses in the previous 3 months For patients with idiopathic LUT symptoms: -Routine clinical assessments excluding a neurological cause for symptoms For patients with predominant storage symptoms: -Urinary urgency (≥2 episodes per week), urinary frequency (>8/24 h), and/or incontinence -Post-void residual volume < 150 mL For patients with predominant voiding symptoms: -Hesitancy, slow or intermittent stream, straining to void, or relying on catheterisation for bladder emptying For patients with mixed storage and voiding LUT symptoms: -Urgency (≥2 episodes per week), urinary frequency (>8/24 h), and/or incontinence -Hesitancy, slow or intermittent stream, straining to void, or relying on catheterisation for bladder emptying For patients with neurological disease without LUT symptoms: -No episodes of urinary urgency or incontinence; urinary frequency < 8/24 h -No voiding symptoms; post-void residual volume < 150 mL For healthy subjects: -Good mental and physical health -Normal functioning of the LUT -No episodes of urinary urgency or incontinence; urinary frequency < 8/24 h -No malignancy or previous surgery of the LUT or genitalia -No previous spine or pelvic surgery

Exclusion Criteria -Pregnant, breast feeding, or planning to become pregnant during the study duration -Any contraindications to having MRI (e.g., ferromagnetic implants), as assessed by the NMR unit’s MRI safety checklist -Craniocerebral injuries or surgeries -Known neurological disease other than that being used for the investigation -Cognitive impairment, as assessed by a Mini-mental State Examination (MMSE) score < 23 -Presence of additional active urological disease that might explain LUT symptoms -Surgery of the LUT or genitalia within the last year or that is related to the LUT symptoms, as per the discretion of the investigator -Any anatomical anomaly of LUT/genitalia -Active LUT malignancy or metabolic disease, as per the discretion of the investigator - For the functional brain imaging part, additional exclusion criteria apply: - Receiving concomitant treatment for LUTS - Received tibial nerve stimulation or intravesical Botulinum A toxin injections within the previous six months - If on an antimuscarinic medication, unwilling to discontinue for at least 5 days prior to having MRI assessment