Pediatric neurogenic bladder

　　I. Etiology

　　1. Classification methods

　　In urological diseases, neurogenic bladder is the most classified, the most complex, and the most confusing type of disease. To date, no classification has been able to combine the anatomical, physiological, pathological, and symptomatic characteristics of neurogenic bladder into a unified form, and none can meet the needs of clinical prognosis and treatment. The existing classifications are basically summarized as follows:

　　(1) Classification based on the site of nerve lesion: The first type is based on the site of nerve lesion, represented by the Bors-Coman classification method, which divides neurogenic bladder into upper motor neuron type (supraspinal type), lower motor neuron type (infraspinal type), and mixed type according to the site of spinal cord injury.

　　(2) Classification based on bladder function changes: The second type is based on bladder function changes, such as the Wein classification method, which divides neurogenic bladder into storage disorders and emptying disorders according to bladder emptying function. The advantage of this method is that it is more suitable for clinical application.

　　(3) Classification by urinary flow dynamics: Currently, for practical purposes, it is divided into two categories according to bladder storage and emptying, whether there is a sensation, pelvic floor resistance, and whether there is non-suppressible detrusor contraction: ① There is a large amount of residual urine, combined with urinary system symptoms and complications; ② There is no residual urine and cannot be retained, that is, urinary incontinence. The latter accounts for about 1/3 of neurogenic bladder cases, and the classification based on urinary flow dynamics is also receiving more and more attention and application. It can comprehensively consider their mutual relationships while evaluating the conditions of the bladder detrusor and urethral sphincter, and divide the bladder and urethra into normal, hyperactive, and reflexless categories at the same time, and also into coordinated and uncoordinated conditions between the bladder detrusor and urethral sphincter.

　　2. Etiology

　　Common causes of neurogenic bladder in children are:

　　(1) Meningomyelocoele: Recently, due to the increased survival rate of children with meningomyelocoele, the treatment of neurogenic bladder has become more important.

　　(2) Sacral hypoplasia: Common partial defects in the sacrum, with neurogenic bladder present in early infancy, congenital spinal cord abnormalities often accompany motor and sensory disturbances in the limbs.

　　(3) Spinal cord tumor: Although rare in children, spinal cord tumors can lead to epidural metastasis in patients with neuroblastoma, causing spinal cord compression, and neurogenic bladder is not uncommon at this time.

　　(4) Vertebral spondylitis: Although not common, it can cause an epidural abscess, compress the spinal cord, and produce neurogenic bladder, with a history of antecedent infection, fever, systemic symptoms, and radicular pain. Although the bones may be normal when neurogenic bladder occurs, bone destruction will soon appear.

　　(5) Trauma: Rarer in children, spinal cord injury due to spinal fracture can lead to paraplegia, the treatment is the same as in adults. Sometimes neurogenic bladder may occur with widespread pelvic fracture, and the nerves of the bladder may be damaged during rectal or colonic surgery, so the surgical operation should be as close to the intestinal tract as possible. For example, the operations designed by Duhamel and Soave can reduce nerve damage. In addition, the excision of a sacrococcygeal teratoma in neonates or infants can also cause neurogenic bladder.

　　(6) Infection: Occasionally, measles encephalitis or post-polio neurogenic bladder may occur after poliomyelitis, transverse myelitis is mostly caused by viral infection and can cause transient neurogenic bladder, with a good prognosis, but short-term bladder drainage is required.

　　(7) Latent neurogenic bladder: In addition to bladder symptoms, there are no other neurological symptoms.

　　Secondly, Pathogenesis

　　1. Detrusor hyperreflexia combined with urethra:The common characteristics of the condition where the sphincter shows synergistic dyscoordination are: there is the manifestation of detrusor hyperreflexia, there may be detrusor muscle contraction during urination, but the urethral sphincter [internal and (or) external] cannot relax coordinately, and even instead, it strengthens contraction. It is seen in patients with upper sacral nerve lesions, and there can be three types of conditions:

　　(1) Detrusor hyperreflexia combined with external sphincter synergistic dyscoordination.

　　(2) Detrusor hyperreflexia combined with internal sphincter synergistic dyscoordination.

　　(3) Detrusor hyperreflexia combined with external and internal sphincter synergistic dyscoordination.

　　2. Detrusor muscle without reflex combined with urethra:The common characteristics of the condition where the sphincter fails to relax are: the detrusor muscle shows no reflex, there is no detrusor muscle contraction during urination, and the urethral sphincter [internal and (or) external] cannot relax coordinately, and even instead, it strengthens contraction. Unlike detrusor hyperreflexia, since there is no detrusor muscle contraction during urination, it is not called协同失调 (synergistic dyscoordination), but is called spasticity, and it is seen in patients with sacral cord or sacral efferent nerve lesions, and there can be three types of conditions:

　　(1) Detrusor areflexia combined with external sphincter rigidity.

　　(2) Detrusor areflexia combined with internal sphincter rigidity.

　　(3) Detrusor areflexia combined with external and internal sphincter rigidity.

　　3. Urethra external:2. Denervation of the sphincter is one type of detrusor areflexia.

　　Due to the weakness or inability to sustain detrusor contraction, the coordination disorder between the detrusor and the external sphincter or bladder neck, and the relatively high urethral resistance, the bladder cannot be fully emptied, leading to urinary retention. At this time, the intravesical pressure increases, often accompanied by vesicoureteral reflux. Reflux is rare in the neonatal period, but by the age of 10, more than 50% of cases have vesicoureteral reflux, leading to ureteral hydrops, renal hydrops, and urinary tract infection, ultimately causing renal insufficiency and chronic uremia. The importance of neurogenic bladder lies in three aspects:

　　6. 1. It affects the patient's lifespan, as chronic urinary retention and infection can lead to severe renal insufficiency.

　　5. Neurogenic bladder loses control over urination, thus affecting the social activities of children.

　　4. Male patients with neurogenic bladder often have sexual dysfunction after adulthood, including inability to achieve an erection and ejaculation, and also cannot reproduce.

　　The etiology of pediatric neurogenic bladder is mainly congenital, so most cases can be detected early after birth. Acquired cases such as trauma can also be concluded through medical history. Neurogenic bladder has a large amount of residual urine, combined with urinary system symptoms and complications, and urinary incontinence, which can be divided into two types: with and without residual urine. The former is more common. Due to the dysfunction of both the motor and sensory nerves of the bladder, there may be no urinary urge when the bladder is full. Additionally, due to the coordination disorder of the internal and external sphincters and the irregular and weak spontaneous contraction of the bladder wall, it is manifested as a large amount of involuntary urination, dribbling, and a large amount of residual urine, which can reach 200-300ml. Physical examination may show bladder distension in the lower abdomen, along with anal relaxation, lower limb motor disorders, or loss of perineal sensation, also known as saddle paralysis. Congenital spinal dysraphism and spinal dysostosis often lead to urinary (defecation) abnormalities in children after birth, such as skin lesions on the spine, lower limbs, foot deformities, and abnormal gait. In newborns or infants, these two situations are often the reasons for seeking medical attention. In older children, abnormalities are usually discovered by parents during the stage of being able to control urination and defecation and walking. If there is concurrent upper urinary tract damage and infection, symptoms of renal insufficiency may occur. These children often have anemia and hypertension, but stones are not commonly associated. Neurogenic bladder in children is often detected early after birth. Although urodynamic examination is very important, it is often difficult to obtain a complete and true evaluation due to the child's inability to cooperate or under anesthesia. Therefore, it is often necessary to make up for the above deficiencies through detailed medical history inquiries, thorough physical examinations, complete laboratory and imaging examinations, and some necessary special examinations. Medical history and physical examination can not only provide an overview of the child's condition but also have the following functions:

　　1. Distinguish the history that may be related to bowel and bladder function, such as bedwetting history, the child's type of urination, etc.

　　2. Localize neurological damage to confirm and explain the results of urodynamic examination.

　　3. Understand the child's prognosis and provide reference for treatment plans.

　　4. Physical examination: physical examination of the spine, especially the sacrococcygeal region, can understand whether the child has spina bifida or other vertebral development abnormalities; neurological examination such as hypoesthesia or loss of sensation in the saddle area, increased, decreased, or disappeared anal sphincter reflex and bulbocavernosus reflex, etc., are helpful for evaluating the degree and localization of neural damage in the child.

　　Long-term follow-up is required for children with this disease, especially for those with gastric or intestinal bladder augmentation. Urinary tract infection, upper urinary tract damage, and electrolyte balance should be followed up, and whether the bladder expanded by the gastrointestinal tract has any malignant changes should be checked.

　　1. Imaging examination

　　X-ray spine film examination can detect spinal deformities (such as vertebral body deformities) and spina bifida. Voiding cystourethrography can usually show a typical 'Christmas tree' shaped bladder, which can understand the shape and capacity of the bladder during the filling period, and whether there is vesicoureteral reflux and the degree of reflux; during micturition, observing the opening condition of the urethra and bladder neck has certain diagnostic significance for the coordination between detrusor and sphincter muscles, and can exclude congenital lower urinary tract obstruction diseases such as posterior urethral valves. Radionuclide imaging can accurately evaluate the degree of renal function impairment in children. Ultrasound is often used due to its non-invasive nature to understand the upper urinary tract and for long-term follow-up of children.

　　2. Urodynamic examination

　　Including cystometry, electromyography of the external sphincter, urethral pressure measurement, and urinary flow rate measurement, the examination methods include routine urodynamic examination, imaging urodynamic examination, and dynamic urodynamic examination. In addition to urinary flow rate measurement, as a non-natural stimulation examination of bladder and urethral function, urodynamic examination has certain limitations. However, some objective findings, such as the presence of uninhibited contractions in the bladder and electromyographic manifestations of denervation in the sphincter, can still provide important diagnostic information for clinical use. Moreover, it has certain guiding significance for the classification and treatment of neurogenic bladder. For the urodynamic examination of children, it is necessary to consider the degree of development of lower urinary tract neural innervation to prevent one-sided conclusions. Therefore, a comprehensive evaluation of urodynamic results with medical history, physical examination, and imaging findings is necessary to make an individualized and comprehensive diagnosis for children with neurogenic bladder, in order to provide reasonable guidance for treatment.

　　1. Eat light foods mainly, pay attention to dietary regularity.

　　2. Pay attention to eating more nutritious foods, supplementing the nutrients lacking in the body.

　　3. Reasonably diet according to the doctor's advice.

　　Just as there is no single classification, to date, there is no simple and single method for the treatment of neurogenic bladder, and often requires individualized comprehensive treatment.
　　1. Principle Different treatment plans for different children can be completely different due to their conditions, but there are some fundamental treatment principles:
　　(1) Protect kidney function.
　　(2) Prevent and control urinary tract infections.
　　(3) Try to avoid indwelling catheterization and urinary diversion.
　　(4) Try to achieve both controlling incontinence and basically emptying the bladder and urethra to improve the quality of life of the child.
　　2. Principle The understanding and cooperation of the child and the parents are the key to the success of the treatment. It is necessary to fully understand the following situations to reasonably select the treatment plan:
　　(1) The consciousness and intelligence of the child.
　　(2) Whether the child has the ability required for treatment, such as whether they can perform intermittent clean catheterization or voiding training independently.
　　(3) The understanding of neurogenic bladder and the selected treatment plan by the child and the parents.
　　(4) The degree of cooperation between the child and the parents, as well as their economic ability.
　　3. The basic treatment principles of neurogenic bladder determined by the non-surgical treatment according to the Wein classification have good guiding significance for clinical treatment. In addition, numerous treatment methods can also be divided into non-surgical and surgical treatment. Non-surgical treatment includes: ① Catheterization; ② Drug treatment; ③ Nerve block therapy; ④ Other methods such as biofeedback technology, voiding training, etc.