Positive bladder cooling test in neurologically normal young children.

The bladder cooling test, which consists of rapid infusion of 0 to 8C saline into the bladder with simultaneous pressure measurement, was performed in 50 neurologically intact infants and children 6 months to 13 years old. The patients were referred for urodynamic investigation because of various disorders of the lower urinary tract. A positive bladder cooling test was defined as a sustained reflex detrusor contraction of about the same magnitude as the micturition contraction. The test was positive during the first 4 years of life but typically negative in children older than 5 years. These findings indicate that a positive bladder cooling test is an infant reflex response that, with the maturation of the central nervous system, becomes suppressed by descending signals from higher centers.