Although urinary symptoms are rare at first presentation of multiple sclerosis (MS), up to 90% of patients experience neurogenic lower urinary tract symptoms (NLUTS) over the course of their disease. Patients suffer mostly from detrusor overactivity (DO) (65%), hypocontactile detrusor (25%), and detrusor sphincter dyssynergia (DSD) (35%). There is no transnational consensus on the optimal stepwise management of neurogenic lower urinary tract disease (NLUTD). The existing national guidelines are contradictory, and there exists no uniform recommendation to referral for urodynamic investigation. Several of these guidelines recommend further neuro-urological diagnostics only in presence of urinary symptoms. However, different investigations demonstrated a significant proportion of asymptomatic patients with NLUTD in the urodynamic studies (UDS). Therefore, our aim was to investigate the number and type of NLUTD in asymptomatic patients with MS in our patient cohort. Furthermore, we tried to identify clinical parameters, which allow to determine the need of further neuro-urological investigation in asymptomatic persons with MS.

We included prospectively collected data of 256 persons with MS originating from the neuro-urological unit of an inpatient neurological rehabilitation centre. Exclusion criteria were age < 18 years, pregnancy or breastfeeding, untreated acute lower UTI, or no written informed consent. Clinical parameters ((voided volume (VV), standardized voiding frequency (SVF)) was obtained from a two-day bladder diary (BD). In addition, we conducted uroflowmetry (UF), including post-void residual (PVR), and UDS according to ICS standards. Information on the number of treated UTIs during the last 6 months was obtained from the patient history. The thresholds of the clinical parameters were defined according to the results of a previous investigation. We defined UDS findings indicative of NLUTD according to current doctrine: first desire to void < 100 ml or strong desire to void < 250 ml or abnormal sensation or bladder capacity < 250 ml or bladder compliance < 20 ml/cm H2O or any type of DO or DSD.

In our study 26% (50/196) of the patients were subjectively asymptomatic (no urinary complaints). The analysis of these asymptomatic patients showed 77% (27/35) UDS results indicative of NLUTD, 20% (7/35) had DO, and 14% (5/35) DO and DSD. There were no asymptomatic patients with bladder compliance < 20 ml/cm H2O (0/35). The clinical parameters voided volume ((relative risk (RR) 1.33, confidence interval (CI) 1.06 – 1.68, p=0.015)) and urinary tract infection rate (RR 1.32, CI 1.09 – 1.6, p=0.005) had significant correlations with urodynamic findings indicative of NLUTD. None of the asymptomatic patients showed abnormal SVF (0/28). The clinical parameters PVR and abnormal UF had no significant correlations with UDS results indicative of NLUTD.

More than one fourth of our study cohort have subjectively no urinary complaints. Without any further diagnostical investigation we wouldn´t detect a considerable proportion of potential NLUTD in this group of patients with MS and therefore we would miss the opportunity of early diagnosis and therapy. BD and history of UTI can help to objectify the absence of symptoms.

Persons with MS should be examined for NLUTD regardless of the presence of urinary symptoms. BD and assessment of UTIs are mandatory for every person with MS.