Recent studies on multiple sclerosis (MS) showed longer survival times from clinical onset than older hospital-based series with a moderate overall excess mortality compared with the general population (standardized mortality ratio [SMR], 1.48; 95% confidence interval [CI], 1.41–1.55]) [1]. Excess mortality increase after 20 years of disease (SMR, 2.20 [2.10–2.31]) [1]. In clinical practice, we are going to manage more and more MS aging population, without strong knowledge on the specificity of aging with MS [2,3]. On the other side, micturition disorders are frequent in MS, approximately 78% of all MS patients will develop lower urinary tract symptoms (LUTS) during the disease [4]. Clinical and urodynamic characteristics of urinary dysfunction in MS are well described : urgency, frequency, urgency urinary incontinence are predominant with an estimated prevalence of 37%–99% whereas obstructive disorders are reported in 34%–79% of patients, leading to chronic urinary retention in 25% of patients [5]. Detrusor overactivity (DO) is the major bladder dysfunction with a prevalence of 65% (34%–99%), however 25% of MS patients have detrusor underactivity, 35% (5%–83%) have a detrusor sphincter dyssynergia and 1to 34% have a normal cystometry [5,6].

Otherwise, aging can determine numerous and various bladder dysfunctions [7-10]. Thus, urinary incontinence (urgency and stress urinary incontinence [SUI]) is more frequent in elderly and voiding dysfunction secondary to obstructive lesions in male (benign prostatic hypertrophy) or female (prolapse) can be observed in this population [7-10].

If MS and aging could determine separately urinary disorders, it could be interesting to evaluate in elderly MS if aging modify the typology of clinical features and therapeutic options.

Yet, some studies have demonstrated that age is not an influencing factor on clinical or urodynamic profile but these studies concerned a young population (age range, 35.9–48 years) [11-14].

Thus, clinical and urodynamic profile of LUTS in geriatric population of MS remains unknown. Because of the consequences of LUTS on upper urinary tract, quality of life, mood, social relationship, risk of falling and the prevalence of osteoporosis, falls, comorbidities and gait disturbance in geriatric population of MS, characterization of urinary disorders is important to get an optimum care [2,3,15,16].

The aim of the present study is to compare the clinical and urodynamic characteristics of urinary disorders in a geriatric population with a nongeriatric population of MS patients.

This study was conducted retrospectively based on the first clinical and urodynamic evaluation in one day hospitalization in Neuro-urology Department of a University Hospital between 2010 and 2016. For each patient with MS aged 65 and older, 2 patients with MS aged less than 65 years old were matched in sex, form of MS, and Expended Disability Status Scale (EDSS).

Demographic data (body mass index and duration of the MS), urinary symptoms using the Urinary Symptom Profile (USP) [17] history of symptomatic urinary tract infection, bladder management (intermittent catheterization, indwelling urinary catheter, or micturition), use of diapers or condom catheter, urinary treatment, quality of life (Qualiveen) [18,19] and repercussion of LUTS on daily life activities and psychological state using a visual analogue scale (VAS) were collected. The following parameters were analyzed: detrusor activity, maximum urethral closure pressure (MUCP), detrusor compliance, and cystometric capacity.

Conventional cystometries was assessed in accordance with International Continence Society (ICS) recommendations [20-22].

Statistical analysis was carried out using R 3.2.3 software (R Foundation for Statistical Computing, Vienna, Austria, http://www.R-project.org) and R studio version 1.0.136. Differences between the 2 populations of age (elderly or not) were evaluated using Student test for quantitative variables and chi-square or Fischer exact tests for categorical variables.

This study was approved by a local ethics committee (Comité de Protection des Personnes Ile de France II: 00001072). Since it was retrospective and no formalized informed consent was necessary according to the ethics committee, a letter was sent to the patients informing them that their data would be used, unless they contacted the investigators to express their disapproval.

In the elderly population of patients with MS, 24 patients were included and matched with 48 patients MS aged 65 or older. The mean age was 69.8 years old (standard deviation [SD], ±3.2) in the elderly population and 49.4 years old (SD, 9.3) in the less than 65 years old population. The mean EDSS was 6.4 (SD, ±1.2). All the subjects had both spinal cord and brain localization of MS plaques. Duration of MS was significantly longer in the elderly population than in the less than 65 years old population (20 years [SD, ±13.3] vs. 13.4 years [SD, ±9.4], P=0.04).

In the male population, 5 patients aged ≥65 years were matched with 10 patients ages <65 years. The MUCP was lower in the elderly population than in the nongeriatric population (49.3±30.0 cm H2O vs. 136.0±83.4 cm H2O, P=0.02) without difference in SUI (USP SUI: 0.6±1.3 vs. 1.1±3.0, P=0.67). There was no statistical difference in any other clinical or urodynamic endpoints (Table 1).

In the female population, 19 patients aged ≥65 years were matched with 38 patients ages <65 years. Voiding symptoms was more described in the nongeriatric population (USP low stream: 3.4±3.5 vs. 1.7±2.4, P=0.04), geriatric population had less urinary treatment (P=0.05). The MUCP was lower in the elderly population than in the non-geriatric population (33.3±16.1 cm H2O vs. 63.0±25.4 cm H2O, P<0.001) without difference in SUI (USP SUI: 3.6±3.7 vs. 2.9±3.3, P=0.47) (Table 2). In the female elderly population, LUTS had less impact on psychological state (VAS for impact on psychological state: 30.0±31.2 vs. 57.4±29.4, P=0.01), on daily life activities (VAS for impact on daily life activities: 38.2±30.1 vs. 56.7±29.5, P=0.04) and on quality of life (Qualiveen: 1.4±1.0 vs. 2.1±0.9, P=0.02) (Table 2). There was no statistical difference in any other clinical or urodynamic endpoints (Table 2).

With equal EDSS, sex, and MS form, geriatric population of male patients with MS has the same urinary disorders and the same impact on quality of life than a nongeriatric population of MS. In contrast, in the female population of patients with MS, voiding symptoms are less prevalent in the geriatric population than in the nongeriatric population, probably due to lower MUCP. LUTS impact less on psychological state, daily life activities, and quality of life in the geriatric female population than in the nongeriatric female population.

In the female population, Hannestad et al. [23] reported similar findings: the prevalence and the severity of incontinence increases with age while the rating of incontinence as a problem remains stable.

According to previous findings, we found that, MUCP is lower in the elderly population than in the less than 65 years old population [23,24]. There is no consensus in the ICS for the definition of intrinsic sphincter deficiency (ISD) [25]. The most commonly studied parameters to determine ISD are Valsalva leak point pressure (VLPP) and MUCP. Lower values of VLPP (typically <60 cm H2O) or MUCP (<20–30 cm H2O) are commonly used as an indicator of ISD [25]. Without consensual definition of ISD, only value of MUCP was presented in this study. Prevalence of SUI was not different between the 2 populations. These results are not consistent with those observed in general population. Indeed, in general population, SUI increases with aging, and MUCP decreases with age [23,24]. In our geriatric population, stress situation was uncommon because of disability, lack of mobility, and age that could explain the absence of SUI in daily life. Furthermore, the similarity of SUI in the 2 populations could be explained by the detrusor sphincter dyssynergia present in suprasacral damage in MS. This detrusor sphincter dyssynergia could also explain the voiding symptoms in the young female group.