Involuntary detrusor contractions: Correlation of urodynamic data to clinical categories

Data regarding the prevalence and urodynamic characteristics of involuntary detrusor contractions (IDC) in various clinical settings, as well as in ne urologically intact vs. neurologically impaired patients, are scarce. The a im of our study was to evaluate whether the urodynamic characteristics of I DC differ in various clinical categories. One hundred eleven consecutive ne urologically intact patients and 21 consecutive neurologically impaired pat ients, referred for evaluation of persistent irritative voiding symptoms, w ere prospectively enrolled. All patients were presumed by history to have I DC, and underwent detailed clinical and urodynamic evaluation. Based on cli nical evaluation, patients were placed into one of four categories accordin g to the main presenting symptoms and the existence of neurological insult: 1) frequency/urgency; 2) urge incontinence; 3) mixed stress incontinence a nd irritative symptoms: and 4) neurogenic bladder. IDC was defined by detru sor pressure of greater than or equal to 15 cm H2O whether or not the patie nt perceived the contraction; or <15 cm H2O if perceived by the patient. Ei ght urodynamic characteristics of IDC were analyzed and compared between th e four groups. IDC were observed in all of the neurologically impaired pati ents, compared with 76% of the neurologically intact patients (P < 0.001). No correlation was found between amplitude of IDC and subjective report of urgency. All clinical categories demonstrated IDC at approximately 80% of c ystometric capacity. Eighty-one percent of the neurologically impaired pati ents, compared with 97% of the neurologically intact patients, were aware o f the IDC at the time of urodynamics (P < 0.04). The ability to abort the I DC was significantly higher among continent patients with frequency/urgency (77%) compared with urge incontinent patients (46%) and neurologically imp aired patients (38%). In conclusion, when evaluating detrusor overactivity, the characteristics of the IDC are not distinct enough to aid in different ial diagnosis. However, the ability to abort IDC and stop incontinent Row m ay have prognostic implications, especially for the response to behavior mo dification, biofeedback. and pelvic floor exercise. Neurourol. Urodynam, 20 :249-257, 2001. (C) 2001 Wiley-Liss, Inc.