The Neurogenic Bladder Symptom Score (NBSS) is a validated patient-reported outcome measure for neurogenic lower urinary tract dysfunction. For this study, the 24 NBSS items were grouped into seven author-defined clinical domains: incontinence severity (Q2–Q5), incontinence-related behavioural impact (Q6–Q8), storage symptoms (Q9–Q13), voiding symptoms (Q14–Q17), complication burden (Q18–Q21), treatment burden (Q22–Q23), and quality of life (Q24). These item groupings are not formally validated NBSS subscales, but were defined by the authors to provide a clinically meaningful framework for symptom interpretation. Their relationship with objective videourodynamic (VUD) findings, including specific voiding dysfunction subtypes, has not been systematically evaluated. The aim of this study was to examine whether these author-defined NBSS domains differentiate patients according to objective videourodynamic findings and to explore their potential clinical relevance in identifying specific dysfunction patterns.

Thirty-six patients with confirmed neurogenic bladder (25 female, 11 male; mean age 46.8 ± 18.2 years) underwent VUD at a single tertiary centre. Neurological aetiologies were heterogeneous, comprising peripheral/iatrogenic causes (n=16; lumbar surgery n=10, pelvic surgery n=6), central neurological disease (n=13; multiple sclerosis n=9, meningitis-related disease n=2, Parkinson's disease n=2), congenital spinal dysraphism (n=7; spina bifida/spinal dysraphism n=4, tethered cord n=2, meningomyelocele n=1). VUD was performed per ICS Good Urodynamic Practices guidelines. NBSS domain scores (mean ± SD) were compared between patients with and without five VUD findings: detrusor overactivity (DOA), urodynamic incontinence, urgency urinary incontinence (UUI), bladder outlet obstruction (BOO), and detrusor underactivity (DUA). Independent samples t-test or Mann-Whitney U test was applied as appropriate. Statistical significance: p<0.05.

NBSS total was significantly higher in patients with DOA (39.2±8.0 vs 22.7±8.9), urodynamic incontinence (41.3±8.0 vs 25.3±9.0), and UUI (41.4±5.0 vs 27.2±9.5; all p≤0.001). In contrast, total NBSS scores showed no significant variation according to the presence of BOO (30.4±13.6 vs 33.5±9.9, p=0.499) or DUA (31.8±10.0 vs 33.6±12.3, p=0.670). Full domain-level results are shown in the Table.
The incontinence (Q2–Q5), incontinence behaviour (Q6–Q8), and storage (Q9–Q13) domains were consistently higher in DOA, incontinence, and UUI-positive groups (all p<0.030). 
The voiding domain (Q14–Q17) did not significantly differentiate any VUD group. Notably, BOO and DUA patients had virtually identical voiding domain scores (6.5±3.3 vs 6.9±2.8, p=0.689 and p=0.950 respectively). These findings confirm that the NBSS voiding domain captures subjective voiding difficulty uniformly, without discriminating between its mechanistically opposite causes.
The complication, treatment, and QoL domains showed no significant differences across any VUD group (all p>0.08), confirming that these subscales measure patient burden dimensions orthogonal to urodynamic status.

These findings show that author-defined NBSS domains are not equally informative across videourodynamic phenotypes. The incontinence, incontinence-related behavioural, and storage domains were consistently associated with DOA, urodynamic incontinence, and UUI, suggesting that NBSS performs best in identifying filling-phase symptom patterns. In contrast, the voiding domain did not differentiate BOO from DUA, despite their opposite urodynamic mechanisms, indicating that subjective voiding symptoms alone are insufficient to identify the underlying cause of voiding dysfunction in neurogenic bladder. The lack of association between complication, treatment, and QoL domains and objective VUD findings further suggests that these domains reflect overall disease burden rather than specific physiological abnormalities

NBSS domain-level interpretation may provide clinically useful information, particularly for recognizing filling-phase dysfunction such as DOA, urodynamic incontinence, and UUI. However, symptom-based domain scores cannot reliably distinguish the aetiology of voiding dysfunction and should not be used as a substitute for videourodynamic testing. These results support the use of NBSS as a complementary clinical tool that helps characterize symptom burden while objective VUD remains essential for mechanistic diagnosis in neurogenic bladder.