Recently, several studies have investigated the safety and efficacy of the Stoller afferent nerve stimulation (SANS) treatment in Multiple Sclerosis (MS) patients. However, because of the differences among the published protocols (percutaneous versus transcutaneous stimulation, stimulation site, total number of sessions), and the absence of data on the duration of the effect, this treatment is not yet currently included in the rehabilitation programs. The present study aims at evaluating the efficacy of a protocol of SANS in the short- and medium-term follow-up.

The efficacy of the proposed stimulation protocol on the physiological parameters of bladder function will be also investigated.

The primary outcome will be the variation of urinary urgency and incontinence. It will be evaluated by self-reported measuring scales, such as the Overactive Bladder Questionnaire (OAB-q) and the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI SF) in their Italian forms.

The expected outcome is that the treatment of posterior tibial nerve stimulation will reduce the frequency and the urgency of urination, and urinary incontinence. Moreover, results from the follow-up will allow estimating the duration of the expected outcome.

Inclusion Criteria:

• MS diagnosis according to the revised McDonalds criteria. Relapsing-remitting, primary and secondary progressive MS forms are allowed;
• Expanded Disability Status Scale (EDSS) between 2 and 6.5 included;
• MiniMental State Examination ≥ cut off 24/84 by sex/age

Exclusion criteria:

• Any of the following in the month before enrolment: an MS relapse; current corticosteroids therapy because of MS; change in medicines prescribed against fatigue; attending an intensive physical therapy program;
• New or active lesions on a brain or spinal cord MRI scan in the 12 months before the study enrolment;
• Any musculoskeletal disease or any additional neurological disorder
• Urinary infections or surgery in perineal regions
• Skin lesions or carcinoma in situ
• Pregnancy
• Expanded Disability Status Scale (EDSS) ≥ 7;