Neurogenic bladder in children

Neurogenic urinary bladder (NUB, neurogenic bladder dysfunction, detrusor-sphincter dyssynergia) - various disorders of the reservoir and evacuation functions of the bladder, as a result of impaired regulation of urination at various levels (cortical, spinal, peripheral).

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The mechanism of accumulation and emptying of the bladder

The activity of the urinary bladder and urethral sphincters is based on a strictly cyclical function, which can be divided into two phases: accumulation and emptying, which together constitute a single "micturition cycle".

Accumulation phase

The bladder reservoir function is provided by a clear mechanism of interaction between the detrusor and the urethral sphincters. Low intravesical pressure, with a constant increase in urine volume, is due to the elasticity and stretchability of the detrusor. During the period of urine accumulation, the detrusor is in a passive state. In this case, the sphincter apparatus reliably blocks the exit from the bladder, creating urethral resistance that is many times greater than the intravesical pressure. Urine can continue to accumulate even when the elastic reserves of the detrusor are exhausted and intravesical pressure increases. However, high urethral resistance allows urine to be retained in the bladder. Urethral resistance is 55% provided by the tension of the striated muscles of the pelvic diaphragm and 45% by the work of the internal sphincter made of smooth muscle fibers controlled by the autonomic nervous system (sympathetic - 31% and parasympathetic - 14%). When alpha-adrenoreceptors, located primarily in the bladder neck and initial urethra, interact with the mediator norepinephrine, the smooth muscles of the internal sphincter of the urethra contract. Under the influence of beta-adrenoreceptors, located over the entire surface of the detrusor, the muscle that expels urine (i.e., the detrusor) relaxes, which ensures the maintenance of low intravesical pressure in the urine accumulation phase.

Thus, the sympathetic nervous system mediator norepinephrine, when interacting with alpha receptors, contracts the smooth muscles of the sphincter, and with beta receptors, relaxes the detrusor.

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Emptying phase

Voluntary contraction of the detrusor is accompanied by relaxation of the external sphincter with emptying of the bladder under relatively low pressure. In the neonatal period and in children of the first months of life, urination is involuntary, with the closure of reflex arcs at the level of the spinal cord and midbrain. During this period, the functions of the detrusor and sphincter are usually well balanced. As the child grows, three factors are important in the process of forming the urination regime: an increase in the capacity of the bladder by reducing the frequency of urination; acquisition of control over the sphincter; the appearance of inhibition of the urination reflex, which is carried out by inhibitory cortical and subcortical centers. From 1.5 years of age, most children acquire the ability to feel the filling of the bladder. Cortical control over the subcortical centers is established by the age of 3.

Neurogenic dysfunction of the bladder can be the cause of the occurrence, progression and chronicity of such diseases of the urinary system as vesicoureteral reflux (VUR), pyelonephritis, and cystitis.

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Pathogenesis of neurogenic bladder

The pathogenesis of neurogenic bladder is complex and not fully understood. The leading role belongs to hypothalamic-pituitary insufficiency, delayed maturation of the centers of the urination regulation system, dysfunction of the autonomic nervous system (segmental and suprasegmental levels), impaired sensitivity of receptors and detrusor bioenergetics. In addition, a certain adverse effect of estrogens on the urodynamics of the urinary tract is noted. In particular, hyperreflexia in girls with unstable bladder is accompanied by an increase in estrogen saturation, causing an increase in the sensitivity of M-cholinergic receptors to acetylcholine. This explains the predominance of girls among patients with functional urination disorders.

Pathogenesis of neurogenic bladder

Symptoms of neurogenic bladder

All symptoms of neurogenic bladder are conventionally divided into three groups:

1. manifestation of bladder diseases of exclusively neurogenic etiology;
2. symptoms of complications of neurogenic bladder (cystitis, pyelonephritis, vesicoureteral reflux, megaureter, hydronephrosis);
3. clinical manifestations of neurogenic lesions of the pelvic organs (colon, anal sphincter).

Symptoms of neurogenic bladder

Diagnosis of neurogenic bladder

The condition of the bladder is assessed by the number of spontaneous urinations per day with normal drinking and temperature conditions. Deviations from the physiological rhythm of spontaneous urinations are the most common symptoms of neurogenic bladder.

To determine the type of neurogenic bladder, it is necessary to examine the rhythm and volume of urination and conduct a functional study of the bladder.

Diagnosis of neurogenic bladder

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Treatment of neurogenic bladder

Treatment of neurogenic bladder is a complex task that requires joint efforts of nephrologists, urologists and neuropathologists with a complex of differentiated corrective measures. For patients with neurogenic bladder, a protective regime is recommended with the elimination of psychotraumatic situations, with full sleep, refusal of emotional games before bedtime, and walks in the fresh air.

How is neurogenic bladder treated?