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.