Cold perception of the bladder during ice water test. Study on 120 patients

If the pathophysiology of bladder cooling reflex (BCR) elicited during an ice water test (IWT) is well-known (triggered by activation of cold receptors within the bladder wall supplied by unmyelinated C fiber afferents) and is widely used for the diagnosis of upper motor neurological lesions, the significance of having a perception of cold in the bladder (PCB) during IWT has not been properly defined yet.

Hundred and twenty patients undergoing IWT were analyzed and separated into four groups: group 1 (G1): patients with idiopathic overactive bladder syndrome (OAB); group 2 (G2): patients with functional dysuria (difficult urination due to bladder-neck obstruction, or congenital large bladder); group 3 (G3): patients with multiple sclerosis (MS) and group 4 (G4): patients with cauda equina syndrome (CES). All patients had a cystometry and IWT. After performing IWT, the patients were asked specific questions regarding the various sensations experienced during the cystometry and IWT, especially for detecting the presence or not of a cold sensation when their bladder was filling up.

Patients with idiopathic OAB had more frequently a PCB than patients with MS (P<0.02). Patients with bladder-neck obstruction were more likely to retain a PCB than patients with CES (P<0.01). Lack of PCB is more frequent in patients with neurological diseases (P<0.001), with a sensitivity of 66% and specificity of 65%.

Patients without neurological disease have a heightened PCB during the IWT than patients with neurological diseases. The lack of PCB may reflect an alteration of the afferent pathways or spinal reflex pathways or central neural pathways.