[Bladder instability in the elderly patient with obstructive prostatic hypertrophy: comparative urodynamic study using non-obstructed women of the same age].

62 men with prostatic hypertrophy and bladder obstruction and 31 age matched women without lower urinary tract obstruction, underwent urodynamic testing which included uroflowmetry, gas cystometry, urethral pressure measurement: electromyography and pressure flow study was only performed to the patients with prostatic hypertrophy. No patient with neurological disease, diabetes mellitus, pelvic operation, neoplasm or stone of the bladder was admitted to the study. Involuntary detrusor contractions (unstable detrusor) were found in 74.2% of male patients and in 25.8% of female patients. In male patients aged over 72 the percentage was 81.8% while in the female patients of the same age was 60%. All the 62 male patients underwent prostatectomy. Two months after surgery, acystometry was done. Unstable detrusor was found in 63.1% of cases. Patients over 80 had a percentage of 100%. These data suggest obstructive prostatic hypertrophy as an important factor in development of involuntary bladder contractions, but the primary pathophysiological factor appears to be age of patients.