Percent Post-Void Residual over Bladder Capacity has the Strongest Correlation to the Highest White Matter Tracts in Women with Multiple Sclerosis and Voiding Dysfunction

Choksi D1, Schott B1, Salazar B2, Khader H3, Lincoln J3, Khavari R2

Research Type


Abstract Category

Female Lower Urinary Tract Symptoms (LUTS) / Voiding Dysfunction

Abstract 99
Open Discussion ePosters
Scientific Open Discussion Session 7
Thursday 8th September 2022
12:35 - 12:40 (ePoster Station 2)
Exhibition Hall
Multiple Sclerosis Voiding Dysfunction Incontinence Female
1. Texas A&M College of Medicine, ENMED Program, 2. Houston Methodist Hospital, Department of Urology, 3. McGovern Medical School

Rose Khavari




Hypothesis / aims of study
Multiple Sclerosis (MS) is an autoimmune inflammatory disease affecting white matter tracts and can lead to bladder storage and/or voiding dysfunction (VD). VD refers to abnormally slow and/or incomplete micturition, based on uncharacteristically slow urine flow rates and/or excessive post-void residuals (PVR). However, the absolute values of PVR of urine are unreliable metrics in the setting of MS where bladder capacity (BC) and compliance can also be decreased. The Expanded Disability Status Scale (EDSS) allows for quantification of disability in MS and for monitoring the changes in severity of disability over time; it is the most widely accepted measure for tracking disability progression in MS patients. We hypothesize that % post-void residuals/bladder capacity (%PVR/BC) correlates strongly with both EDSS and changes in white matter integrity as seen on Diffusion Tensor Images (DTI).
Study design, materials and methods
Ten adult women (>18 years of age) with clinically stable MS for ≥3 months and VD defined as %PVR/BC > 40% or Liverpool nomogram percentile less than the 10th percentile were recruited from our tertiary Neuro-urology Clinic. Patients participated in a clinical Urodynamic Study (UDS) and completed several questionnaires (i.e. Urogenital Distress Inventory (UDI-6), NBSS, AUASS). DTI images were acquired using a 7-Tesla Siemens MAGNETOM Terra MRI scanner (Matrix = 158 x 158, slick thickness 1.4 mm, Field-of-View (FOV) = 220 X 220 cm2, 64 directions, b-value = 1000 s/mm2, with a total scan time of 12 minutes and 14 seconds). DTI maps were constructed, and individual patients were co-registered with the ICBM-DTI-81 white matter atlas, which is a reference coordinate system containing the probabilistic locations of 50 white matter tracts, averaged from 81 different individuals9. The open-source software Analysis of Functional NeuroImages (AFNI) was utilized to extract FA and MD values. Spearman’s correlation test was performed between each WMT and clinical parameters both objective (9 parameters from uroflow and UDS such as PVR, BC, MCC, etc.) and subjective (19 parameters from validated questionnaires). Spearman’s correlation test was also performed between clinical parameters and the EDSS score as well. P-values < 0.05 were considered statistically significant.
Clinical parameters showing correlation with the highest number of WMTs are shown in Figure 1. Of these, %PVR/BC obtained from the average of multiple un-instrumented uroflow assessments had significant correlations to the greatest number of WMTs when assessing FA and MD. Furthermore, we observed that in all recorded clinical parameters, %PVR/BC had the strongest equivalence to the EDSS score (Figure 2).
Interpretation of results
%PVR/BC seems to be a suitable metric to evaluate VD in women with MS, where the bladder capacity can be variable and the absolute value of PVR may be unreliable. However, an important limitation exists: We must confirm that the regions of the white matter locus that correlate to the severity of VD in MS patients are localized to the same areas of the greatest white matter lesion burden.
Concluding message
Results from this study demonstrate that %PVR/BC can be used as a reliable, objective parameter with which to gauge voiding efficacy and response to therapy in MS patients.
Figure 1 Clinical Parameters with Correlations to the Greatest WMTs
Figure 2 Clinical Parameters with the Five Strongest Correlations to EDSS
  1. Karmakar D, Sharma JB. Current concepts in voiding dysfunction and dysfunctional voiding: A review from a urogynaecologist's perspective [retracted in: J Midlife Health. 2018 Jan-Mar;9(1):50]. J Midlife Health. 2014;5(3):104-110. doi:10.4103/0976-7800.141185
Funding Dr. Khavari reports that she is partially supported by R03DK126994-01 awarded by the National Institute of Health, NIDDK (RK). Also supported by Houston Methodist Clinician Scientist Award (RK). Clinical Trial Yes Registration Number NCT03574610 RCT No Subjects Human Ethics Committee Houston Methodist Institutional Review Board Helsinki Yes Informed Consent Yes
06/07/2024 20:01:18