Outcome of the bladder cooling test in children with nonneurogenic bladder problems.

Purpose: The bladder cooling test (BCT) engages a primitive neonatal spinal reflex that becomes suppressed by descending signals in older children and may reappear with suprasacral lesions. We assessed the outcome of the BCT in a large group of children with nonneurogenic bladder problems.
Materials and Methods: The BCT was evaluated in a consecutive series of 178 girls and 106 boys, 1 month to 18 years old with bladder problems without overt neurology. The test was performed at the end of routine cystometry by a rapid control infusion of body warm saline followed, after fluid evacuation, by the same volume of cold saline (3 to 10C). The test was considered positive if a detrusor contraction greater than 30 cm H2O was evoked by the cold but not the warm fluid.
Results: Most children younger than 4 years had a history of pyelonephritis (29 of 34) and/or had vesicoureteral reflux (grade IV to V in 26 of 34). For those younger than 2 years 87% of the BCTs were positive while only 21% of the tests were positive in 2 to 3-year-old children. Most children older than 4 years had idiopathic urge incontinence, and greater than 50% of the BCTs were positive in the youngest (less than 6 years) with a gradual decline to 0% at age 13 years.
Conclusions: Conversion of positive to negative BCTs at about age 2 years presumably represents normal maturation while positive tests in older incontinent children suggest delayed maturation of the central neuronal control of the bladder.