The role of urinary nerve growth factor for the diagnosis and assessment of the biofeedback success in children with dysfunctional voiding

Abstract

Dysfunctional voiding (DV) occurs in neurologically normal children who are not able to establish brain control on detrusor muscle contractions (DMCs). It is also reported to be the result of incorrect voiding habits during toilet training. Children contract pelvic floor muscles (PFMs) to suppress DMC and DV begins. Urinary nerve growth factor (uNGF) is necessary for the synthesis and regulation of neurotransmitters, development of dorsal root ganglia (sensory neurons), and development of sympathetic cells during embryonic and post-natal life. uNGF has also a role in the intracellular signal transduction in nerve cells towards the target organ. To our knowledge, no study has investigated the association between uNGF, biofeedback treatment and DV in children. The aim was to examine the potential effect of uNGF in the assessment of the effectiveness of biofeedback success in children with lower urinary tract disorders. Fifty-two children with the suspicion of DV and 48 children from a primary school reporting no urinary complaints were enrolled in this study from October 2010 to April 2013 in the Urology Department. uNGF levels were compared. The mean uNGF/creatinine (Cr) level was 0.23 ± 0.26 in the control group and 0.96 ± 0.88 in the DV group (p < 0.001). The mean uNGF/Cr levels in the DV group at baseline and at the end of biofeedback therapy at 6 and 12 months were 0.90 ± 0.78, 0.26 ± 0.32, and 0.40 ± 0.50, respectively (p < 0.001) (Figure). To our knowledge this study is the first to show the correlations between uNGF levels and biofeedback therapy in children with DV. Tissue NGF in 12 patients with overactive bladder (OAB)/detrusor overactivity and 15 healthy women was previously compared and it was suggested that there was no correlation between bladder tissue NGF and OAB. uNGF levels in the bladder in patients with interstitial cystitis and idiopathic sensorial urgency were evaluated previously, and uNGF levels reported. Similar to these reports, most of the previous studies handled uNGF in patients with diseases such as interstitial cystitis, OAB, urinary tract infections, urolithiasis, spinal cord injury, and prostate cancer, and found significantly higher uNGF levels. These studies were generally in adults. A previous study about uNGF comprised 40 children with OAB, in contrast to other studies. According to this study, 40 children diagnosed with OAB were administered anti-muscarinic therapy (oxybutynin 0.3-0.5 mg/kg/day). It was reported that uNGF/Cr levels of the OAB group were higher than control group. In the current study, we evaluated the uNGF difference in DV and the effect of biofeedback treatment on uNGF levels. uNGF levels were higher in children with DV and decreased after biofeedback therapy. uNGF levels could be used for the diagnosis and the assessment of biofeedback success in these children.