spina bifida occult
Introduction
Introduction to recessive spina bifida Recessive spina bifida is the most common type of recessive spinal canal insufficiency. It is more common in the lumbosacral region. The lamina with one or several vertebrae is not fully closed, but the contents of the spinal canal are not bulging. Most of the recessive spina bifida does not produce symptoms for life and does not have any external manifestations. Most of them are simple spina bifida (simplespinebifidaoccult), which is only the fusion of lamina and spinous processes, most of which are located in the lumbosacral region and less than 1% in other parts. Generally no symptoms, no treatment; a small number of recessive spinal canal occlusion (Occultspinaldysraphism), may have symptoms such as the nervous system, but also may have a meningocele protruding into the chest or pelvic cavity, so surgical treatment is required. basic knowledge The proportion of illness: 0.85% Susceptible people: no special people Mode of infection: non-infectious Complications: chondromas, lipoma, epidermoid cyst, dermoid cyst, teratoma, arachnoid cyst
Cause
Cause of recessive spina bifida
Spinal cord and spinal nerve damage (50%):
Mainly due to spinal cord and spinal nerve damage in the affected segment, that is, related to the degree of compression and nerve damage. Local skin may have increased hair, the skin is sunken inward, and some have irregular capillary hemangioma or pigmentation. The onset is early and late, some have developed in infants and young children, and some symptoms appear in adulthood, which is consistent with a series of secondary pathological changes caused by spina bifida and aggravation of the tethered cord and ischemic changes. .
Genetic factors (25%):
Gene chain inheritance is a phenomenon similar between biological parents and offspring, and between offspring individuals. Genetics generally refers to the phenomenon that the traits of the parent are expressed in the next generation, but genetically refers to the phenomenon that the genetic material is passed from the upper generation to the offspring.
Environmental factors (25%):
Such as early pregnancy, such as radiation, poisons, hormonal drugs, anaerobic acidosis and other adverse stimuli.
Pathogenesis
The atresia of the neural tube takes about 10 days from the embryo's 17 to 19 days, and the lamina and myocardium differentiated from the mesoderm, a total of 42 pairs of body segments, gradually heal from the 4th to 7th body segments. First, the anterior nerve hole is locked in about 24 days (23 to 26 days), followed by 26 days (26 to 30 days), and the posterior nerve hole is locked. During this period, the mesodermal tissue exists between the neural tube and the ectodermal dermis ( The body segment) forms the vertebrae. The healing of the total vertebral arch is about 8 weeks after the embryo, and then the end of the neuroembryo formation is completed. The anterior neural tube covering the ectoderm of the skin is further extended to the tail end. During this period, the neuroectodermal and mesoderm are used. Leaves are the origin, vacuolization occurs in the undifferentiated cell group at the end of the anterior neural tube, and then these vacuoles gradually fuse to form a tubular structure (formation of the posterior neural tube), and the two neural tubes eventually bind to form a spinal cord. Base, this process is called tube building. The spinal cord primordial in the spinal canal is 40 to 48 days old in the embryo. The tail of the spinal cord is degenerated and degenerated, forming the terminal filament of the spinal cord. The degeneration of the spinal cord is still carried out after birth. The result is at the end. Side of silk The position of the medullary cone gradually moves upwards, so that the conus of the spinal cord located in the 2-3 plane of the embryo in the 56 to 60 days of the embryo is located at the waist 4 at the 20th week of the embryo, 2 to 3 at the waist at birth, and reaches the waist at the time of adulthood. ~ 2 level.
The human central nervous system, the brain and spinal cord, develops in the first month of the embryo; at the second week of the embryo, the dorsal side forms a nerve plate, the sides of the nerve plate are convex, the middle is concave, and the convex portions on both sides gradually The connection is closed at the top, and at the 3rd to 4th week of the embryo, the neural tube is formed. If the closure of the neural tube is blocked at this stage, the bone or skin defect covering the central nervous system is caused, and the nerve tube is at the forefront. It closes on the 24th day of the embryo, and then forms the brain after repeated differentiation and division. The closure of the nerve hole at the end of the neural tube occurs on the 27th day of the embryo and differentiates into the lumbosacral region of the spine. The neural tube and its covering During the closure process, the abnormalities appear to be incompletely closed, and the neural tube occlusion is at most at the two ends of the neural tube, but any part between the two ends of the neural tube may occur. If it occurs at the front end, the skull is split. The brain tissue is destroyed and forms a brain-free deformity. If it occurs at the tail end, the spine is cracked. The spinal cord can be completely exposed, or it may bulge in a capsule called spina bifida and meninges. Out.
There are many pathological forms of recessive spina bifida. The simple recessive spina bifida does not involve other spinal cord or neuropathy. The content of the spinal canal does not bulge outward. The appearance of the dorsal spine is mostly normal skin and sometimes local hyperplasia. , pigmentation spots, flaky capillary hemangioma, skin recession, skin fistula, etc., these complex pathological changes, often cause tethered cord and compression.
Prevention
Recessive spina bifida prevention
Because recessive spina bifida is the result of a combination of genetic and environmental factors, care should be taken to prevent environmental factors such as radiation, poisons, hormonal drugs, anaerobic acidosis and other adverse stimuli in early pregnancy. Helps prevent the prevention of recessive spina bifida.
Complication
Recessive spina bifida complications Complications chondroma lipoma epidermoid cysts dermoid cysts teratoma arachnoid cysts
Complex recessive spina bifida often has spinal cord or neurodevelopmental abnormalities, such as local scars, adhesions, terminal silk hypertrophy and thickening, which fixes the spinal cord to the vertebrae and limits the upward movement of the spinal cord during development, or both. , lipoma, epidermoid cyst, dermoid cyst, teratoma, arachnoid cyst, end of spinal cord cavity, formation of nerve root diverticulum, gliosis in the spinal cord or central tube dilatation, sometimes combined with hemivertebra, vertebral side Bending, intervertebral foramen and ribs develop malformations.
Symptom
Recessive spina bifida symptoms Common symptoms Spinal gliosis Proliferation at the humerus Persistent pain, sensory disturbances, reflexes, disappearance, horseshoe varus, arched foot, varus, paraplegia
The symptoms of recessive spina bifida are mainly caused by the spinal cord and spinal nerve damage of the affected segment, that is, related to the degree of compression and nerve damage. Local skin may have increased hair, the skin is inwardly depressed, and some have irregular capillaries. Tumor or pigmentation, the incidence of early and late, may have occurred in infants and young children, some symptoms appear in adulthood, which and spina bifida caused a series of secondary pathological changes and the tethered cord is gradually aggravated, ischemia occurs The changes are consistent. According to their clinical symptoms, there are mild, moderate, and severe symptoms, but there are quite a few patients with spina bifida who do not develop symptoms for life.
1. Mild symptoms: The symptoms at the onset are weak limb muscles, mild muscle atrophy, numbness, enuresis, sometimes manifested as low back pain or leg pain, mostly affected by one lower limb, but also have muscle weakness in both lower limbs, check The manifestations of peripheral nerve damage were found, that is, the muscle tension of the limb was low, the flaccid mild muscle weakness, the lower limbs and the perineum were shallow, and the deep feeling was reduced.
2. Symptoms: The above-mentioned exercise and sensory disturbances are more obvious. There are often horseshoe varus deformities, sometimes low back pain, sciatica or urinary incontinence.
3. Severe symptoms: obvious lower extremity muscle strength, or even paralysis; feelings also significantly reduced or disappeared, often accompanied by neurotrophic changes, lower extremity cold, cyanosis, nutritional ulcers, and some often occur in the appendix Ulceration, sacral nerve distribution area skin sensory disturbance is obvious, long-term lower limbs show disuse atrophy, Achilles tendon reflexes disappear or contracture, foot deformity can appear up toe foot, arched foot, foot varus or eversion, some patients show Complete paraplegia and urinary incontinence, and some for bowel movements, urinary incontinence, a small number of patients with disc herniation or lumbar spondylolisthesis, there are still symptoms of upper limbs caused by tethered cord.
Examine
Examination of recessive spina bifida
1. Spine X-ray plain film of anterior and posterior and lateral images of the lumbar vertebrae, showing pedicle widening, lamina defect, lack of spinous processes, sometimes multiple spina bifida, or simultaneous vertebral deformity, spinal side Bend and so on.
2. CT and MRI scans, especially MRI, are more clear in the diagnosis of spina bifida and tethered cord. They can show the position of the spinal cord at the end of the spinal cord, reaching the lumbosacral junction or the fistula, local adhesions and other signs. Today, myelography has been Replaced by MRI.
Diagnosis
Diagnosis and diagnosis of recessive spina bifida
diagnosis
According to the local skin hairy, purple spot, small concave, pigmentation and other clinical manifestations, combined with the symptoms of nerve damage, the diagnosis is more difficult, especially long-term enuresis or obvious urinary incontinence, should be considered for spina bifida, spine X-ray Plain film and CT and MRI scans help to diagnose the disease.
Differential diagnosis
Recessive spina bifida needs to be differentiated from lumbar disc herniation, lumbar muscle strain, myalgia, spinal cord tumor, etc. Adults also need to be differentiated from spinal stenosis. CT and MRI scans can be used for diagnosis.
