Phasic or terminal detrusor overactivity in women: age, urodynamic findings and sphincter behavior relationships

To search for relationships between phasic (P) and terminal (T) DO with age, urodynamic findings and sphincter behavior during involuntary detrusor contraction in woman.

Urodynamic studies (triple lumen catheter 7F, seated position) of 164 successive women referred for LUTS with diagnosis of DO were reviewed. Patients were stratified in 4 sub-groups: pre- (18-44 y), peri- (45-54 y), post-menopause (55-74 y) and oldest old (= 75 y). The urethral sensor was positioned at the level of the maximum urethral closure pressure for sphincter behavior analysis. A variation of at least 5 cmH(2)O in pressure (detrusor or urethra) was chosen to assert DO or sphincter response. Sphincter response was classified as relaxation (re) before or during DO, or steady (st).

Occurrence of P and TDO was similar: 77 P and 87 T. The PDO group was significantly younger (p = 0.0003). TDO was more frequent in patients with a history of neurological disease. The percentage of PDO remained almost constant in age groups, while that of TDO increased with age from 6.7% to 23.2% (p = 0.0013). Uninhibited contraction occurred at a smaller bladder volume in the P group: 149 ± 95 vs. 221 ± 113 mL (p < 0.0001). Steady sphincter predominated in the TDO subgroup: 45.9% vs. 32.1% and increased significantly in each DO sub-group of ≥ 75 y.

Steady sphincter during both P and TDO, and occurrence of TDO appear as specific of aging. The last result could be related to structural changes in the detrusor muscle with aging.