Objective: To investigate the variation in urodynamic variables during repeated filling cystometry and the impact that the variability had on the observed incidence of detrusor overactivity, to evaluate the correlation of detrusor overactivity with the symptoms of urge in men with lower urinary tract symptoms (LUTS), and to compare the variability of detrusor overactivity in men with LUTS to that in men with spinal cord injury (SCI).
Patients and methods: Sixty men with LUTS and 35 with neurogenic bladders after SCI were assessed. Investigations included the International Prostate Symptom Score (IPSS), Madsen-Iversen Symptom Score (MSS), uroflowmetry, filling cystometry and pressure-flow, in three successive studies.
Results: In men with LUTS, a significant decrease in the number and pressure of involuntary detrusor contractions (IDCs) in consecutive cystometries resulted in a reduction of observed detrusor overactivity from 72% to 63% and 48%, in the three studies. Urgency scores were significantly lower in men who became 'stable' than in those who remained 'unstable' throughout the three studies. In men with SCI, cystometric variables and detrusor overactivity remained consistent over sequential studies.
Conclusion: Urodynamic detrusor overactivity is affected by repeated cystometry. In men with LUTS, two populations with detrusor overactivity were identified; one group adapted to repeated filling while another had persistent IDCs and greater urgency scores. The latter group had bladder behaviour similar to that of men with neurogenic bladders secondary to SCI. These findings might be important in explaining the cause of symptoms, initiating further investigation, and predicting the outcome of therapy.