Fetal spinal bifida

　　During the third week of embryogenesis, the two neural folds fuse towards the dorsal midline to form the neural tube, starting from the middle (equivalent to the thoracic segment) and extending upwards and downwards to both ends, closing by the fourth week. After the formation of the neural tube, it gradually separates from the epidermis and moves towards the deep part, gradually forming a brain vesicle at the head end of the tube, and the rest of the areas develop into the spinal cord. In the third month of embryogenesis, the components of the spine are formed by the two mesoderm leaves and form the vertebral canal in a ring shape around the neural tube. At this time, if the neural tube does not close, the pedicle of the vertebrae cannot close and remain open, and can develop into a myelomeningocele. The occurrence of spina bifida is related to various factors, and all kinds of abnormal factors that affect fertilization and pregnancy can promote the formation of this malformation. Initially, the spinal cord is as long as the vertebral canal, and after the third month, the growth rate of the spinal cord is slower than that of the spine, causing the position of the spinal cord end to gradually rise. At birth, the end of the spinal cord is at the level of L3, and at one year old, it rises to the first and second lumbar vertebrae. After that, it stays at this segment.

　　Ectopic spina bifida can be divided into meningocele (meningocele), myelomeningocele (myelomeningocele), mylocele (mylocele), etc. Myelomeningocele is formed by primary neural ectodermal malformation or secondary normal spinal cord splitting. When the neural tube does not close, the superficial ectoderm does not separate from the underlying neuroectoderm, so the mesenchyme cannot move into the space between the neural tube and the superficial ectoderm, leading to the inability to form normal vertebral, cartilage, muscle, and spinal ligament structures, making it lack these structures. A red, highly vascular, flat, non-fusible nerve plate can be seen in the middle of the back, and if checked carefully, a neural groove can be seen in the middle of the nerve plate, which extends upwards to become the central canal. Since this disease can cause an increase in alpha-fetoprotein, it can be easily diagnosed during pregnancy. Spinal cord meningocele is related to some risk factors.

　　6. The complications of隐性骶骨脊柱裂 are spinal cord tethering during the period of development, damaging the cauda equina nerve.

　　5. Spinal cord meningocele can be complicated with hydrocephalus. The survival rate of the child's surgery has recently reached 80-93%. The higher the damage site, the lower the survival rate. 70% of the death cases in surgical death occur in the first two years after surgery. The causes of death include ventriculitis accounting for 24-45%, complications of hydrocephalus and shunting surgery accounting for 19-30%, pneumonia accounting for 22%, and kidney complications accounting for 11%.

　　3. Spinal cord split or spinal cord herniation can easily cause meningitis, and children often find it difficult to survive.

　　4.显性脊柱裂 can be complicated by flaccid paralysis of both lower limbs and incontinence of urine and feces.

　　Brain malformations and intellectual disabilities can occur in children with myelomeningoceles, including various brain malformations such as incomplete lobe development, multiple cerebellar gyri, cleft brain, incomplete corpus callosum, arachnoid cysts, anencephaly, and hypoplasia of the brain. Examination of the brain tissue reveals cellular migration anomalies, particularly prominent in the brainstem.

　　Hydrocephalus can occur in 80% to 90% of children with myelomeningoceles, and the incidence of spinal cord malformation with hydrocephalus at the lumbosacral region is relatively low.

　　Sphincter function: 80%-90% of children with spinal meningocele can have neurogenic bladder dysfunction, such as urinary retention, infection, cysts, vesicoureteral reflux, and chronic renal failure, etc.

　　Late-onset neurological complications, such as increased limb spasticity, increased level of segmental motor or sensory dysfunction, progressive neuromusculoskeletal deformities, or worsening of scoliosis.

　　Chiari II malformation: almost completely seen in patients with spinal meningocele, including underdevelopment of the cerebellar vermis and tonsils, elongation of the fourth ventricle, and descent of the cerebellar tonsil and inferior brainstem into the spinal canal. In infants, symptoms include dysphagia, aspiration, apnea, weak crying, paralysis of the cranial nerves, and growth disorders, etc.

　　1) Meningoceles: More common in the lumbosacral region. The main pathological change is that the dura mater bulges outward through the defect in the vertebral plate to reach the outside, forming a median cystic mass on the back. Its contents, in addition to a few nerve root tissues, are mainly cerebrospinal fluid, so the light transmission test is positive, and there is a sensation of fluctuation when pressed. Root symptoms appear under heavy pressure. The tension of this cystic mass increases when abdominal pressure is increased or when infants cry. The skin surface color is usually normal; in a few cases, it becomes thin and brittle, and is adherent to the dura mater.

　　2) Spinal meningocele type: More common than the former. The contents of the protrusion, in addition to the dura mater, also include the protrusion of the spinal cord itself into the cyst. It is seen above the thoracolumbar segment, with a larger bone defect at the posterior aspect of the spinal canal. The base of the protruding cyst is wider. The light transmission test is often negative, and symptoms of the spinal cord can appear when hand pressure is applied (it should be avoided to perform compressive examination). It is often accompanied by lower limb nerve disorders and sphincter dysfunction.

　　3) Spinal meningocele: That is, the spinal cord is exposed to the outside, a segment of the spinal cord is exposed to the outside in a flat manner, without skin over the protruding area of the spinal cord, with the spinal canal and dura mater open. Accompanied by a large amount of cerebrospinal fluid leakage, a granulation surface may form on the surface. This is the most severe type, often accompanied by lower limb or other systemic diseases, with a high mortality rate.

　　Spina bifida is generally divided into two types: exostosis of the spine and concealed spina bifida.

　　1. Exostosis of the spine: A severe congenital disease, with very different clinical symptoms depending on the extent of involvement of the spinal cord tissue. Although it can be seen at the forehead and root of the nose, more than 90% occur at the lumbosacral region.

　　(1) Meningoceles: More common in the lumbar and lumbosacral regions. The pathological change is mainly the meninges bulging outward through the defect in the vertebral plate to reach the subcutaneous tissue, forming a median cystic mass on the back. Its contents, in addition to a few nerve root tissues, are mainly cerebrospinal fluid, so the light transmission test is positive, and there is a sensation of fluctuation when pressed. Root symptoms appear under heavy pressure. The tension of this cystic mass increases when abdominal pressure is increased or when infants cry. The skin surface color is usually normal; in a few cases, it becomes thin and brittle, and is adherent to the dura mater.

　　(2) Spinal meningocele type: less common than the former. In addition to the meningeal hernia, the spinal cord itself protrudes into the cyst, which is seen above the thoracolumbar segment, with a larger bone defect at the posterior aspect of the spinal canal. The base of the protruding cyst is wider, and the light transmission test is often negative. Hand pressure can cause symptoms of the spinal cord (it should be avoided to perform compressive examination). It is often accompanied by symptoms of lower limb nerve disorders.

　　(3) Type with fatty tissue in the meninges (or meningo-spinal) bulge: Refers to the two previous types, with varying amounts of fatty tissue in the cyst. It is less common.

　　(4) Meningocele with spinal cord cystic bulge: Refers to the meningocele of the spinal cord with cerebrospinal fluid accumulation. This type is severe and has many clinical symptoms, making it difficult to develop normally due to complications and often leading to early death.

　　(5) Extradural type: Refers to the complete splitting of the central canal of the spinal cord, which is exposed externally in an inverted manner, accompanied by a large amount of cerebrospinal fluid leakage and the formation of granulation tissue on the surface. This is the most severe type, as it often accompanies lower limb or other systemic malformations, and most have paralysis of both lower limbs, with complex symptoms and a very high mortality rate.

　　(6) Anterior type: Refers to the protrusion of the meninges forward to the body cavity. This type is very rare in clinical practice and is only found in MR examinations.

　　2. Hidden spina bifida: More common than the former, as it is not accompanied by abnormalities of the dura sac, and there are few complaints in clinical practice, so those who need treatment are even rarer. Generally, it is divided into the following 5 types.

　　(1) Unilateral type: Refers to the fusion of one side of the vertebral plate with the spinous process, while the other side, due to incomplete development of the vertebral plate, does not fuse with the spinous process, forming a longitudinal (or oblique) fissure on the side of the median line. This type can be found in clinical practice, and simple malformations of this kind generally do not cause symptoms.

　　(2) Floating spine type: Refers to the incomplete development of both sides of the vertebral plates, which do not fuse with each other, forming a relatively wide gap. Since the spinous processes are in a free floating state, it is called 'floating spine'. The two sides of the vertebral plates are connected with fibromembranous tissue. This type is often accompanied by local symptoms in clinical practice, and severe cases may require surgical treatment.

　　(3) Kissing spine type: Refers to the incomplete development of bilateral vertebral plates of one vertebral segment (usually the first sacral vertebra), with absent spinous processes. The spinous process of the upper vertebral segment is longer, so when the waist is extended, the spinous process of the upper vertebral segment is inserted into the posterior fissure of the next vertebral segment, resembling a kiss, hence the clinical term 'kissing spine' or 'locked spine'. Local or radicular symptoms may occur, and for severe cases, surgery should be performed to partially or completely resect the lower part of the spinous process of the upper vertebral segment.

　　(4) Complete spina bifida type: Refers to the incomplete development of bilateral vertebral plates with absent spinous processes, forming a long fissure. This type is often found in clinical X-ray films, with 90% of the cases showing no symptoms.

　　(5) Mixed type: Refers to cases with other malformations in addition to spina bifida, among which the most common are fused vertebral arches and transitional vertebrae.

　　Spina bifida is a type of neural tube defect characterized by the herniation or exposure of the meninges or spinal cord through an incompletely closed vertebral column. Neural tube defects are malformations caused by defects in neural tube development during embryogenesis. Severe cases can lead to damage to the sacral nerve, motor impairment of the lower limbs, incontinence of urine and feces, and even paralysis. Infection can lead to cerebral palsy. It is irreversible. Before the 1990s, the incidence of neural tube defects in newborns in China was 2.3‰-2.8‰, accounting for 1/4-1/3 of the world's newborn neural tube defects, making it the country with the highest incidence.

　　In the late 1990s, humans discovered the cause of congenital neural tube defects - a lack of a nutrient called "folic acid" in pregnant women. China has promoted prenatal care since the 1990s and has formulated a scheme for taking folic acid orally starting 3 months before pregnancy and continuing for 3 months after pregnancy. According to the "B" ultrasound during pregnancy and the determination of alpha-fetoprotein in the serum of pregnant mothers and amniotic fluid, neural tube defects can be screened out in the early and middle stages of pregnancy, which has greatly reduced the incidence of neural tube defects.

　　There are no related laboratory tests, and the main examination methods are as follows: three.

　　1. X-ray films show spinal canal malformations, defects in spinous processes and vertebral plates.

　　2. Translucency test of the mass: if the content is cerebrospinal fluid, it is uniformly translucent; if it is spinal cord or fat, it is not translucent.

　　3. Computed tomography or magnetic resonance imaging of the spine at the corresponding mass site shows that the mass communicates with the spinal canal through the fissure, and the inside can be cerebrospinal fluid or spinal nerve.

　　In addition, from the different types of fetal spinal defects, we can see their laboratory examination results.

　　Manifest spinal defects:

　　Due to the畸形 on the surface of the child, it is often discovered by family members or midwives in the early stage. According to clinical manifestations, X-ray films of the spine show defects in spinous processes and vertebral plates. Cerebrospinal fluid can be aspirated from the cyst cavity, and the diagnosis can be established. MRI examination can show the spinal cord and nerves within the protruding mass, and can also show spinal cord cavitation and other malformations. The skin changes of this disease need to be differentiated from congenital pilonidal sinus, where the wall of the sinus tract is composed of skin tissue, the length of the sinus tract varies, the shorter ones are blind tubes, and the longer ones can reach the spinal canal, which may cause infection or concurrent tumors.

　　Hidden spinal defects:

　　More than 80% of cases may have no symptoms or positive signs in clinical settings, and they are often discovered incidentally during physical examinations. Some patients with hidden spinal defects may experience increasingly obvious urinary disorders during growth, and they may still have urinary incontinence during the school age, which is caused by adhesions and tight pulling of the cauda equina at the site of the bone fissure, leading to a spinal cord tethering syndrome. MRI can show the descent of the conus medullaris, thickening of the cauda equina, and transverse diameter greater than 2mm. Certain types (such as floating spines) due to poor development of the lumbosacral structure, are prone to lumbar muscle strain and other chronic low back pain symptoms. Local compression may cause pain or radiating symptoms of lower limb nerves, especially when the lumbar spine is excessively flexed or extended. Diagnosis requires normal X-ray films or CT scans.

　　A reasonable diet refers to the nutrition provided by three meals a day, which must meet the needs of human growth, development, and various physiological and physical activities. "The way to maintain health is to start with food." Utilizing the nutrition of food to prevent and treat diseases can promote health and longevity. As the saying goes, "Food supplements are better than medicine supplements." What is meant by food supplements is that they can play a role that medicine cannot.

　　People obtain various nutrients and energy through diet, which helps maintain their health. A reasonable diet with sufficient nutrition can improve the health level of a generation, prevent the occurrence and development of various diseases, prolong life, and enhance the quality of the nation. Unreasonable diet, overnutrition or undernutrition, can bring varying degrees of harm to health. It is evident that a reasonable diet is extremely important. It is best to supplement folic acid, collagen, spirulina, and calcium in milk during daily life.

　　1. Osteocele

　　(1) For simple meningocele or mild neurological symptoms: surgery should be performed as soon as possible. If surgery is delayed due to general condition or other reasons, local protection should be provided, especially for those with exposed spinal cord, to prevent infection.

　　(2) Surgical Principles: The procedure is to return the prolapsed spinal cord or nerve root to the spinal canal (first separate and relax the adhesions around it), then remove the redundant dura mater and repair the defect of the vertebral plate (bone grafting, etc.).

　　(3) Lower limb symptoms caused by incomplete development of spinal cord nerves: appropriate orthopedic surgery or orthopedic brace treatment can be selected after repair surgery, and it can also be carried out simultaneously.

　　2. Hidden Spinal Bifida

　　(1) General cases: More than 99% of cases do not require treatment, but medical knowledge popularization education should be carried out to eliminate patients' tension and negative psychological states.

　　(2) For patients with mild symptoms: emphasis should be placed on the strengthening of lumbar and back muscles (or abdominal muscles) through exercise. To enhance the local intrinsic balance of the lumbar spine.

　　(3) For patients with severe symptoms that have affected normal work and life: further examinations should be conducted first to determine whether there is a combined lumbar spinal canal or root canal stenosis, lumbar intervertebral disc herniation (protrusion) or vertebral arch fracture, etc. For accompanying patients, treatment of the latter should be the main focus, including surgical treatment.

　　(4) Floating Spine Syndrome: Surgery should not be performed lightly. The early efficacy of simple floating spine resection is often unsatisfactory, mainly because the deep fibrous tissue below the floating spine is often adherent to the dura mater, which is often the cause of symptoms. It is often difficult to cut this adherent tissue, and caution should be exercised. Generally, while removing the floating spine, the yellow ligament is cut and flipped to both sides.

　　(5) Kyphosis: The tip of the spinous process can be amputated by surgery.

　　For patients with long-term urinary incontinence or nocturnal enuresis or persistent exacerbation of neurological symptoms due to hidden spinal bifida, appropriate surgical treatment should be given after careful examination. The purpose of the surgery is to remove the fibrous and fatty tissues that compress the nerve roots.

　　For patients with complete paralysis of both lower limbs at birth and incontinence of urine and feces, or with obvious hydrocephalus, it is usually difficult to recover normally after surgery. Symptoms may even worsen or other complications may occur.