The bladder cooling reflex and the use of cooling as stimulus to the lower urinary tract.

PURPOSE

We review the physiology of bladder cooling response in experimental animals and humans, and present its clinical usefulness.

MATERIALS AND METHODS

We describe experimental studies of the bladder cooling response, and more recent clinical retrospective and prospective studies of the bladder cooling test in adults and children.

RESULTS

Studies indicate the existence of a segmental spinal bladder cooling reflex that originates from specific cold receptors in the bladder and urethral walls supplied by unmyelinated C-afferents. The reflex is positive in neurologically normal infants and children until about age 4 years. It becomes negative with further maturation of the nervous system but may be unmasked by pathological processes that disturb the descending neuronal control of normal voiding. A positive test in a patient with an overactive bladder requires further neurourological evaluation.

CONCLUSIONS

The bladder cooling response originates from cold receptors within the walls of the lower urinary tract. The cooling response represents a neonatal reflex that may be unmasked by central neuropathology, analogous to the appearance of the Basbinki sign in pyramidal tract lesions. The bladder cooling test is a simple and valuable tool to support the diagnosis of neurourological disorders.