A long-term study of the persistence of the urodynamic characteristics of the unstable bladder.

Sixty-four patients with normal bladder function, stress incontinence, idiopathic instability or instability associated with enuresis underwent pressure/flow videocystography. This was repeated from one month to 8 years later (average 19.4 months). Filling cystometry remained qualitatively unchanged in 95% of cases overall, whilst the actual pressure recordings during cystometry in the 37 patients with instability remained identical or very similar in 73%. The results demonstrated the accuracy of cystometry and the consistency of bladder dynamics over the longest period so far reported in these apparently non-progressive disorders.