Kiwi scientists have found in pig bladders a breakthrough that could lead to better diagnosis and treatment of a disorder which frequently catches its sufferers short.
In Western countries such as New Zealand, overactive bladder syndrome affects around 16 per cent of women over 40 and more than 60 per cent of female rest-home residents.
Scientists had believed the disorder was caused by a generalised adjustment in the tension of the bladder wall which caused it to relax slightly, which led to a dramatic pressurising when water entered the bladder.
But now, Massey University scientists have revealed that, rather than one big change, the process occurred in patches that moved in circuits over the surface of the bladder.
"It's rather like, instead of spray-painting an entire room with a bomb, what you've got is somebody going around with a brush progressively painting it and then coming around and painting it again," said Professor Roger Lentle, who leads a Massey team investigating the bladder.
Using pig bladders, the team developed a technique to track the tiny movements made by the bladder wall during its accommodation of incoming urine.
The mapping algorithm worked by mathematically comparing successive frames of a video film so changes not visible to the human eye could be identified.
The results surprised the team and could make for a "game-changer" in the diagnosis of the syndrome, Professor Lentle said.
The next step was to find non-invasive ways to map the movements, then apply it in tests to compare women with normal bladders against those with the disorder.
The team's findings, published in the British Journal of Urology and reviewed by premier journal Nature, could provide for the first time an effective way to diagnose the troublesome disorder.
Until now there have been no tests able to identify the disorder in the walls of the bladder. Diagnosis is further hampered by similar symptoms caused by other disorders.
Professor Lentle said the research could also prove to be the first step on a path to targeted drugs that could correct the process.
"We've got a way to go yet, but we have enormous promise in that we are now starting to unravel how the bladder manages to accommodate urine when it's coming in from the kidney."