Does defective volume sensation contribute to detrusor underactivity?

Area of Science:

• Urology
• Urodynamics
• Neuro-urology

Background:

• Detrusor underactivity (DU) in neurologically intact, unobstructed patients is often attributed to sensory deficits rather than detrusor contractility issues.
• Understanding the sensory component of DU is crucial for accurate diagnosis and management.

Purpose of the Study:

• To investigate the urodynamic characteristics of detrusor underactivity (DU) in neurologically intact, unobstructed patients.
• To compare volume and wall stress at sensation thresholds and voiding contractility between DU patients and those with stress urinary incontinence (SUI), detrusor overactivity (DO), and increased sensations (IS).

Main Methods:

• Retrospective chart review of urodynamic studies in neurologically normal, nonobstructed symptomatic patients.
• Comparison of urodynamic parameters including age, gender, pressure/volume data, wall stress at sensations, and voiding parameters among four groups: DU, SUI, DO, and IS.
• Calculation of wall stress at sensation thresholds.

Main Results:

• The DU group showed higher volume thresholds for strong desire compared to the IS group.
• DU and DO groups exhibited higher wall stress at strong desire than IS and SUI groups.
• While Watts factor was similar, DU patients had smaller voided volumes and higher post-void residuals (PVRs).

Conclusions:

• Elevated volume and wall stress at strong desire in DU patients suggest diminished central sensitivity to bladder afferent activity.
• Similar contractility but reduced voided volumes and elevated PVRs in DU support a sensory contribution to the condition.
• These findings highlight the role of impaired volume sensation in detrusor underactivity in non-neurogenic, nonobstructed patients.