[Non-neurogenic lower urinary tract dysfunction]

Functional bladder disorders in children are a common condition and they are observed in 5-15% of pediatric population. Recent observations of bladder function of the healthy newborns have changed our viewpoint on its behaviour in older children. By the age of 4 years, many if not most children have matured their urinary tract function and developed an adult pattern of urinary control. They are generally dry during the day and the night. The adult pattern is characterized during bladder filling by an absence of unstable or uninhibited (involuntary) detrusor contractions. Urodynamic studies have confirmed that even at bladder capacity and when the desire to void is strong, detrusor contraction will not occur unless it is voluntarily initiated. The voiding symptoms and urinary incontinence or urinary infection and are thought to be caused by behavioral factors that affect toilet training and prevent successful transition from the infantile to the adult pattern of urinary control. These syndromes of dysfunctional elimination differ greatly in manifestation, prognosis, and pathophysiology and comprise a clinical spectrum that varies widely. At the severe end of the spectrum are a small group of patients with Hinman's syndrome, also termed the non-neurogenic neurogenic bladder, dysfunctional voiding, or occult neuropathic bladder. Less severe uropathology is observed in the large group of children who present with refractory and often severe symptoms that reflect incomplete toilet training with diminished urinary control. Their obstruction is caused by an incoordination between bladder and sphincter that occurs only during bladder filling in the presence of unstable bladder contractions and is, therefore, of less potential risk to the urinary tract. Unstable bladder, the most common pattern of urinary dysfunction in childhood, occurs in up to 57% of symptomatic children aged 3 to 14 years. Voluntary constriction of the urinary sphincter during unstable bladder contractions produces urinary obstruction with high intravesical pressures. The assessment of children with lower urinary tract disorders should consist of a detailed history, a frequency/volume chart and a physical examination. Uroflowmetry and ultrasound examination can be added. Treatment of functional bladder disorders in children can be divided in urotherapy, consisting of standard therapy and some specialized types of urotherapy like biofeedback, neuromodulation, pharmacotherapy and botulinum toxin injections.