Can a faked cystometry deceive patients in their perception of filling sensations? A study on the reliability of spontaneously reported cystometric filling sensations in patients with non-neurogenic lower urinary tract dysfunction.

Aims: To evaluate the reliability of spontaneously reported bladder sensations during real and faked cystometry in patients with non-neurogenic lower urinary tract dysfunction.

Methods: Fifty-nine patients with non-neurogenic lower urinary tract dysfunction were submitted to a real and faked filling cystometry and were asked to describe all bladder-related sensations they experienced during the investigations. All patients were told that the bladder had to be filled twice, but during the faked cystometry, no water was infused in the bladder.

Results: During the real cystometry, the normal pattern of filling sensation was reported by 88%. During the faked cystometry, none of the patients reported the normal pattern of filling sensations. Five patients reported first sensation of filling, one first desire to void (FDV). None of the patients reported a strong desire to void (SDV) during the faked cystometry.

Conclusions: Asking patients with a non-neurogenic lower urinary tract dysfunction to report on the bladder filling sensations during cystometry is a valid method for sensory evaluation. A minority of patients may report some sensation of bladder filling even without actual bladder filling. Memory and habituation may play a role in the perception of bladder sensation and one should be aware of this. However, reporting some sensation during faked cystometry not necessarily means the evaluation of the perception of bladder filling is unreliable.