spina bifida
Introduction
Introduction to spina bifida Spinal fissure refers to the formation of a cleft in the dorsal or ventral side of the spine due to congenital spinal dysplasia. It may or may not be accompanied by malformations of the meninges and nerve components. Clinically, such malformations are very common in the census population. It accounts for 5% to 29%. It occurs mostly in the 1st and 2nd atlas and the 5th lumbar vertebrae. The main reason for this is the developmental disorder of the cartilage center or the osteogenesis center in the embryonic stage, so that the bilateral vertebral arches do not fuse at the back to form a wide and narrow fissure. Simple bony fractures are called recessive spina bifida, the most common; if accompanied by meningocele or spinal cord bulging, it is dominant spina bifida, accounting for 1 2 , the latter is quite difficult to treat, and Mostly in the category of neurosurgery. basic knowledge The proportion of illness: 0.002% Susceptible people: no specific population Mode of infection: non-infectious Complications: hydrocephalus ventriculitis pneumonia meningitis
Cause
Spinal fissure
Causes
At the third week of the embryonic period, the neural crests on both sides fuse to the dorsal midline, forming a neural tube, which starts from the middle (equivalent to the thoracic segment) and then develops upward and downward, and closes at the 4th week.
After the neural tube is formed, it gradually separates from the epidermis and moves to the deep part, gradually forming a cerebral vesicle at the head end of the tube, and the rest develops into a spinal cord.
At the 3rd month of the embryo, the spine component is formed by the mesoderm on both sides, and the spinal canal is formed in a circular shape to form the spinal canal. At this time, if the neural tube is not closed, the pedicle can not be closed and remains open. State, and can develop spinal meningocele.
The occurrence of spina bifida is related to a variety of factors, and all kinds of abnormal factors affecting fertilization and pregnancy may contribute to the formation of such malformations.
At the beginning, the spinal cord is as long as the spinal canal. After the third month, the position of the end of the spinal cord gradually increases due to the slower growth rate of the spinal cord than the growth rate of the spine. At the time of birth, the end of the spinal cord is at the level of the waist 3, and at the age of 1 Between the 1st and 2nd lumbar vertebrae, I have been stuck in this section since then.
Prevention
Spinal fissure prevention
Spina bifida is a type of neural tube defect. It is a congenital malformation characterized by the meninges or spinal cord passing through an incompletely closed spine. The neural tube defects are deformities caused by neural tube defects during embryonic development. Patients with impaired phrenic nerve, lower extremity dyskinesia, incontinence and even paralysis, infected people can cause cerebral palsy, irreversible, before the 1990s, the incidence of neonatal neural tube defects in China was 2.3-2.8, accounting for The world's neonatal neural tube defects are 1/4-1/3, which is the highest incidence. In the late 1990s, humans discovered the cause of congenital neural tube defects. Pregnant women lacked a nutrient called folic acid. In China, since the 1990s, we have promoted pregnancy care, and formulated a regimen for oral administration of folic acid from the first 3 months of pregnancy to 3 months after pregnancy for cervical malformations, and based on the "B" super pregnancy and the maternal serum and amniotic fluid. The determination of protein can detect neural tube defects in the early and middle stages of pregnancy, which greatly reduces the incidence of neural tube defects.
Complication
Spinal fissure complications Complications hydrocephalus ventriculitis pneumonia meningitis
1. The complication of recessive sacral spina bifida is that the developmental stage causes the spinal cord to damage the cauda equina.
2. Spinal meningocele can be combined with hydrocephalus. The surgical survival rate of sick children has recently reached 80-93%. The higher the lesion, the lower the survival rate. 70% of the surgical deaths occur in the first two postoperative cases. In the year of death, ventriculitis accounted for 24 to 45%, hydrocephalus and shunt complications accounted for 19 to 30%, pneumonia accounted for 22%, and renal complications accounted for 11%.
3. Spinal cord fissure or spinal cord bulging is very likely to cause meningitis, and it is often difficult for children to continue to survive.
4. Dominant spina bifida can be complicated by flaccid paralysis of lower limbs and incontinence.
Symptom
Spinal fissure symptoms common symptoms spinal gliosis proliferative segmental dissociative sensory sensation intervertebral space changes sinus phase sacral dysplasia
symptom
A small number of patients can develop symptoms such as enuresis and urinary incontinence after adulthood. Some newborn babies have a bulging bag at the waist. The wall is very thin and permeable. When the baby is crying, the tension of the bag is increased. If it is broken, it is easily infected and causes meningitis. This type is caused by the bulging of the spine from the spine cleft, which is called "spondylolysis" or "cystic spina bifida". If the spinal cord and nerve tissue in the spinal canal also bulge, it is called "spinal meningocele", which can cause weakness of both lower limbs, muscle atrophy, children will walk later, but gait claudication, buttocks and back of thigh The skin feels dull or numb, ulcers can occur on the soles and buttocks, the urine and the feet can not be controlled, and adults have symptoms such as impotence. A small number of patients may have a spinal cord that is completely exposed to the cleft, and some may have a thin fibrous membrane covering the surface. This type is called "exposed spinal cord", the symptoms are more serious, and it is easy to be infected, and the prognosis is extremely poor. Patients with spina bifida are often associated with congenital dysplasia in other parts of the body; such as foot varus, foot valgus, arched foot, congenital hydrocephalus, scoliosis, etc.
Type
Generally, the spina bifida is divided into two types: dominant spina bifida and recessive spina bifida.
Dominant spina bifida
For a serious congenital disorder, the clinical symptoms vary greatly depending on the degree of involvement of the spinal cord tissue. Although it can be seen in the head and nasal roots, more than 90% occur in the lumbosacral region.
(1) meningocele type: the waist and lumbosacral region are more common, the pathological changes are mainly the vertebral membrane through the defect of the lamina to bulge to the subcutaneous, forming a median cyst of the back, the content except a few nerves Outside the root tissue, the cerebrospinal fluid is mainly filled, so the light transmission test is positive, the pressure is fluctuating, and the root symptoms appear when the pressure is increased. When the abdominal pressure or the child is weeping, the cystic tension is increased, and the skin surface color is normal; A few are thin, brittle, and adhere to the dura mater.
(2) Spinal cord bulging type: less common than the former, except for the meningocele, the spinal cord itself also protrudes into the sac, which is found above the thoracolumbar region, the bone defect in the posterior spinal canal is larger, and the bulge sac is wider. The light transmission test is more negative, and the symptoms of the spinal cord may occur under the pressure of the hand (the pressure test should be avoided), and the symptoms of the lower limb nerve disorder are often accompanied.
(3) The swell of the meninges (or spinal cord) with adipose tissue: that is, on the basis of the first two types, there are a small number of adipose tissue in the sac, which is rare.
(4) meningococcal cyst swelling type: that is, the spinal cord central tube with hydronephrosis of the meninges, this type of disease is serious, and more clinical symptoms, easy to develop due to complications, easy to die early.
(5) Spinal valgus type: the central tube of the spinal cord is completely ruptured, and is exposed to the body surface, with a large amount of cerebrospinal fluid overflowing, and the surface can form a granulation surface. This is the most serious type, because it is accompanied by lower limbs or Other malformations of the whole body, and many lower limb paralysis, the symptoms are complex, and the mortality rate is very high.
(6) Pre-type: refers to the meningeal bulge forward to the body cavity, clinically rare, only found in MR examination.
2. Recessive spina bifida
More common than the former, because there is no dural sac abnormality, there are few complaints in the clinic, so the need for treatment is more rare, generally divided into the following 5 types.
(1) unilateral type: that is, one side of the lamina is fused with the spinous process, and the other side is not fused with the spinous process due to dysplasia of the lamina, forming a longitudinal (or oblique) fissure of the median side, which can be found clinically. Simple such malformations generally do not cause symptoms.
(2) Floating type: the laminae on both sides of the vertebrae are underdeveloped and do not fuse with each other, forming a wide gap. Because the spinous processes are free floating, they are called "floating spines" and the lamina on both sides Associated with fibrous membrane-like tissue, this type is often accompanied by local symptoms in the clinic, and severe cases require surgery.
(3) The form of the kiss spine: that is, a vertebral ganglion (mostly the first atlas) has bilateral vertebral dysplasia, and the spinous process is also absent, while the spinous process of the previous vertebral segment is longer, so that when the waist is extended, The spine of the last vertebrae is embedded in the posterior fissure of the next vertebra, which is like kissing. Therefore, it is called "kissing spine" in clinical practice, also known as "inlaid spine". Local or root symptoms may occur. Surgery will partially or partially remove the spinous process of the upper vertebra.
(4) Complete spina bifida: refers to bilateral laminar dysplasia accompanied by spinous processes, forming a long-form fissure. This type is often found in clinical X-ray films, 90% of which are asymptomatic. .
(5) Mixed type: refers to those who are accompanied by other deformities in addition to vertebrae, among which the vertebral arch is not connected and the transitional spine is more common.
Examine
Spinal fissure examination
1. X-ray photographs show spinal canal malformations, spinous processes and lamina defects.
2. The light transmission test of the tumor: if the content is cerebrospinal fluid, it is evenly transmitted, and if it is spinal cord or fat, it is opaque.
3. Spine computed tomography or magnetic resonance imaging of the corresponding mass site shows that the tumor communicates with the spinal canal through the cleft, which may be cerebrospinal fluid or spinal nerve.
Diagnosis
Diagnosis and diagnosis of spina bifida
diagnosis
Diagnosis of spina bifida is not difficult, but it is necessary to further judge the type of deformity, the central skin defect of the back and severe neurological symptoms, which is the spinal cord fissure; if it is a cystic mass, the light transmission test is positive, the nervous system is normal, and the spine is normal. X-ray films only show posterior spine, suggesting simple meningocele. On the contrary, it suggests the spinal meningocele; if the cystic mass deviates from the midline, the nervous system symptoms are concentrated on one side, and the spine X-ray shows the midline skeletal septum, the semi-vertebral body, the narrow intervertebral disc, etc. Semi-lateral spinal meningocele.
Identification
This malformation still needs to be differentiated from teratoma, lipoma and dermoid cyst. This type of tumor is more solid than the percussive, the pressure can not be returned, the light transmission test is negative, the surface skin is normal, so the identification is not difficult, but it should be noted that Such tumors often coexist with spina bifida.
