Usefulness of total bladder capacity and post-void residual urine volume as a predictor of detrusor overactivity with impaired contractility in stroke patients

Detrusor overactivity (DO) with impaired contractility (DOIC) is a mixed pattern of involuntary contraction and increased post-void residual urine volume (PVR) which occurs in stroke patients. Urodynamic study results obtained from patients with detrusor abnormalities and stroke were analyzed to identify the associations between various urodynamic parameters and DOIC. Between August 2003 and November 2010, 127 patients were selected from 178 patients undergoing urodynamic study due to urinary symptoms. Stroke patients were divided into three groups: the DO, DOIC and detrusor underactivity (DU) groups. The significance of differences between the three groups was analyzed using the Kruskal-Wallis test and receiver operating characteristic (ROC) curves were used to calculate the accuracy of the urodynamic study result factors to distinguish between the three groups. The average total bladder capacity (TBC) was 219.15±98.30 ml in the DO, 330.25±115.75 ml in the DOIC and 486.00±111.48 ml in the DU (P<0.001) group. The average PVR was 22.64±20.85 ml in the DO, 146.87±95.09 ml in the DOIC and 425.33±136.70 ml in the DU (P<0.001) group. A ROC curve of DO and DOIC revealed that TBC and PVR were significantly different between the DOIC and DO groups. The area under the curve (AUC) of TBC was 0.812 (P<0.001) and that of PVR was 0.987 (P<0.001). A ROC curve of DOIC and DU revealed that TBC and PVR were significantly different between the DOIC and DU groups. The AUC of TBC was 0.813 (P<0.001) and that of PVR was 0.929 (P<0.001). In the urodynamic study of stroke patients with urinary symptoms, TBC and PVR may provide useful information for treating patients who cannot undergo urodynamic study.