Overactive bladder syndrome (OAB) is defined by urgent and frequent urges to urinate associated with frequent night-time urination and sometimes urinary incontinence. Sacral neuromodulation (SNM) is now one of the second-line treatments for OAB.

The mode of action of SNM is still poorly understood but a number of data from recent scientific literature suggest that SNM may act, among other things, by altering the balance of the autonomic nervous system (ANS) - located at the interface between the urinary tract and the brain structures regulating the functioning of the urinary tract.

The aim of this study would therefore be to develop a predictive tool for the effectiveness of SNM.

Inclusion Criteria:

• Male of female ≥ 18 years
• OAB syndrome
• Indication for a two-staged SNM
• Under general anaesthesia with Remifentanil and Propofol
• Patient who has given written consent to participate in the trial
• Patient willing to comply with all study procedures and duration

Exclusion Criteria:

• Tibial neuro-stimulation (last 3 months)
• Sacral neuromodulation (last 3 months)
• Botulinum toxin A intra-detrusor injection (last 9 months)
• Pregnancy in progress
• Administrative reasons
• Guardianship/curatorship