A malformation of the spine, which may be accompanied by pathology of the development of the spinal cord, is Spina bifida. What it is, in what cases it arises, what disorders it can lead to in the body - the reader will find answers to these questions in our article. However, to understand the clinical picture of the disease, it is also necessary to understand the concept of the central nervous system of a person, the anatomical structure of the spine and the functions of the spinal cord.
CNS concept
The central nervous system is the main part of the human nervous system. It is represented by the spinal cord and brain and consists of neurons and their processes. The central nervous system is formed by three departments: lower, middle and higher. The lower and middle include the spinal cord, medulla oblongata, midbrain, diencephalon, and cerebellum. These components regulate the activity of individual organs, establish a connection between them, and ensure the integrity of the functioning of the body. The higher part of the central nervous system is represented by the hemispheres of the brain and functionally ensures the interaction of the body with the environment.
The main function of the central nervous system is the implementation of simple and complex reactions - reflexes. The central nervous system is formed in the first weeks of pregnancy from a special structure - ectoderm. With incorrect division and development of nerve cells , a neural tube defect occurs, which subsequently leads to the development of pathologies of the spinal cord.
The spinal cord is an organ of the nervous system located in the spinal canal. The conditional border between the spinal cord and the brain passes at the intersection of the pyramidal fibers. Both the brain and spinal cord are shrouded in a sheath consisting of three layers: solid, arachnoid and vascular. The cranium protects the brain from external damage, the spinal cord protects the spinal cord.
Spinal column structure
The spine - the basis of the human skeleton, consists of vertebrae, between which are located the intervertebral discs - cartilaginous layers. Functionally disks provide mobility of the spine. In total, a person has 33-34 vertebrae, they are conditionally combined into departments: cervical, thoracic, lumbar, sacral, coccygeal.
Each vertebra is formed by a body, an arch and processes. The body and the arc make up the vertebral foramen, the processes connect the vertebrae to each other, and also perform the function of attachment for the muscles. In a healthy human body, the vertebrae openings merge into a single spinal canal, which, in fact, is the location of the spinal cord. But there are also pathological conditions in which there is a gap in the bone - this phenomenon is called "non-closure of the vertebral arches."
The spinal cord provides a link between the brain and the peripheral nervous system. The central channel is the cavity inside the spinal cord. The spinal cord, like the brain, has a three-layer membrane, between the layers of which there is cerebrospinal fluid. The vertebral bone and the outer membrane of the spinal cord form an epidural space between each other, filled with adipose tissue and venous network.
Spina bifida: what is it?
Spina bifida is a dystrophy of the development of the spine (incomplete closure of the spinal canal), which is often exacerbated by another pathology - the underdevelopment of the spinal cord. This defect begins to manifest in the early stages of pregnancy and is a violation in the formation of the neural tube. The neural tube is the structure from which the central nervous system — the spinal cord and brain — forms in the embryo at a later stage of pregnancy. Numerous case histories of patients with Spina bifida give reason to classify the pathology into individual species in accordance with the severity of the development of defects:
- conditionally mild forms: latent Spina bifida, meningocele, lipomeningocele;
- severe forms: myelomeningocele; myelomeningocele complicated by hydrocephalus.
Spina bifida is detected by magnetic resonance imaging or neurosonography.
Statistics show that the disease occurs in 1-2 newborns out of 1000. The pathology is genetic in nature, because up to 8% of repeated births ends with a diagnosis of Spina bifida. Doctors say that more often it occurs in children born to women aged. However, 95% of newborns with a diagnosis of a split spine appear in healthy parents who do not suffer from this ailment.
Light forms of Spina bifida
Hidden Spina bifida (occulta) is the mildest form of the disease, in which there is an underdevelopment, a small gap in the vertebrae. Most often occurs in the lumbar or sacral spine.
This pathology applies only to the bone tissue of the spine and does not affect the spinal structures. The disease is mild and often does not manifest itself as symptoms that may bother a person. Many patients with this pathology do not even suspect their disease. A visually noticeable sign of a disease in a newborn may be a bundle of hair, usually small; fat pouch; deepening or birthmark at the site of pathology.
Only in some cases (in approximately 1 out of 1000 patients with the latent form of Spina bifida) does pathology lead to functional disorders in the urogenital system, intestines, muscle weakness of the lower extremities, and curvature of the spine. Typically, the patient’s medical record indicates the specific vertebra number of one of the spinal sections in which the pathology occurred. For example, the entry “Spina bifida posterior S1” indicates problems with the first vertebra of the sacral spine.
Meningocele is a type of spinal cleavage in which, in addition to bone degeneration, the protective membranes of the brain can protrude or protrude in the form of a capsule through an existing gap. Often the spinal cord, as well as the nerve processes without pathologies or with minor defects. In the vast majority of cases, the capsule is covered with skin, which conditionally protects its contents. However, even this small defect requires surgical treatment to correct a cosmetic defect.
Lipomeningocele
Lipomeningocele is a form of Spina bifida, which is considered a moderate pathology. In medicine, such a disorder is classified as a symbiosis of the resulting spinal hernias and lipomas - benign tumors. This violation in the formation of the neural tube occurs during the first 20 days of pregnancy. Lipomeningocele is a defect that can cause the development of neurological pathologies and leads to serious diseases of the genitourinary system, intestines - adipose tissue puts pressure on the spinal cord. Given the medical history of patients with lipomeningocele, four groups of pathological manifestations of the disease can be conditionally distinguished:
- without neurological, pelvic and orthopedic disorders;
- moderate paresis of the legs, deformation of the feet;
- severe impaired motor function, curvature of the spine, pelvic disturbances;
- limb deformity, severe pelvic pathology.
Therefore, the immediate and early surgical intervention is considered the only and correct method of treatment for this pathology. In conjunction with the operation to remove the fat sack, plastic hernia can be performed.
Myelomeningocele - a severe form of Spina bifida
The most severe form of pathology that occurs in 75% of all cases of vertebral dystrophy is myelomeningocele (Cystica spina bifida). What it is? A cerebral hernia is an element of the spinal cord that protrudes through a defect in the spine.
Sometimes the capsule with the spinal cord is protected by the skin, in other cases, the brain tissue along with the nerve processes comes out. With this form of pathology, neurological disorders are inevitable. The degree of such disorders will be determined by the severity of the spinal cord defect, as well as the area of the spine in which the violation occurred. If the disease affects the final spinal cord, problems affect the genitourinary system and intestines, and paralysis of the lower extremities occurs.
Often spinal hernias occur in the lumbosacral spine. However, in medical practice there are cases when the pathology develops at the level of the thoracic or cervical spine. Unfortunately, a neural tube defect is most often accompanied by another violation - hydrocephalus or Chiari anomaly, the cause of which is a violation of the formation of cerebrospinal cavities inside the skull.
Hydrocephalus and Chiari Anomaly
Hydrocephalus (dropsy of the brain) is a pathology resulting from the accumulation of cerebrospinal fluid in the ventricles of the brain. Cerebrospinal fluid - cerebrospinal fluid - constantly circulates in the ventricular system.
The required volume of cerebrospinal fluid can be formed in two ways:
- produced by the glandular cells of blood vessels in the ventricles of the brain;
- formed as a result of sweating blood plasma through the walls of blood vessels.
Cerebrospinal fluid circulates from the ventricles to the subarachnoid space of the brain and spinal cord. Intracranial and spinal cerebrospinal fluid spaces in a healthy body form a single whole. When a spinal hernia occurs , a communicating hydrocephalus forms. The accumulation of fluid leads to an increase in intracranial pressure, which leads to decreased vision, seizures, strabismus, muscle weakness of the upper and lower extremities. Such disorders lead to severe neurological disorders, a decrease in intellectual abilities, and death.
The Arnold-Chiari anomaly is a pathology in which the tonsils of the cerebellum descend to the level of the first or second cervical vertebrae, thereby blocking the circulation of cerebrospinal fluid.
Surgical treatment of myelomeningocele
The greatest danger to the life of a newborn with myelomeningocele is a rupture of the hernial sac and infection in its contents. Infectious complications, hydrocephalus decompensation - the main reason for the high mortality of newborns who are diagnosed with Spina bifida. As soon as liquorrhea is revealed - the course of cerebrospinal fluid - an emergency surgical intervention is performed to remove the cerebrospinal hernia.
To date, the optimal method for eliminating these pathologies, successfully used throughout the world, is to perform intrauterine removal of spinal hernias. The specified type of surgical intervention prevents the development of hydrocephalus and Chiari anomaly in small patients; avoids severe life-threatening complications, as well as subsequent shunt surgery. The above manipulations give a newborn a chance at a normal level of development and quality of life.
If timely intrauterine surgery is not performed for any reason, resort to liquor-reshunting surgery, which normalizes the amount of cerebrospinal fluid. Typically, such an operation is carried out in two stages. The clinic of the spine is a medical institution with a narrow focus, which, as a rule, helps to solve many problems associated with pathologies of the spine.
Diagnostics
In modern medicine, Spina bifida is diagnosed in early pregnancy. Therefore, future parents have time for understanding the diagnosis and psychological preparation for the birth of a child with special needs. On the other hand, they also have the time and opportunity to decide on non-preservation of the fetus.
During pregnancy (16-18 weeks), expectant mothers undergo screening tests based on a blood test. The essence of the method is to check the concentration of the embryonic protein, which, in the normal course of pregnancy, is produced by the fetus in a small amount. In the presence of a defect in the central nervous system, the concentration of alpha-fetoprotein rises. There are features when conducting a test. Due to the possible occurrence of errors in decoding the analysis results, some rules should be carefully followed:
- set the most accurate gestational age;
- if the pregnancy is multiple, it should be diagnosed in time.
Another diagnostic method is prenatal ultrasound, performed at certain stages of pregnancy, favorable for the detection of pathology. This method allows you to visualize the brain, spinal cord, spinal column and timely diagnosis. However, it must be borne in mind that with minor defects (hidden Spina bifida), the pathology may not be detected.
Amniocentesis - amniotic fluid puncture is another diagnostic method. It is carried out by means of a large needle and only strictly under the control of ultrasound. This method is used when a blood test showed an excess of alpha-fetoprotein concentration, and ultrasound diagnostics did not reveal pathologies. The liquid, like blood, is examined for the concentration of the rudimentary protein, the excess of which indicates the presence of disturbances in the development of the spinal column.
Prevention
Of course, no medical specialist can guarantee that, if all the necessary precautions are taken and there are no well-known risk factors, healthy parents will have a healthy baby. Unfortunately, sometimes nature disposes differently than what a person suggests. But the forces of future mothers and fathers do their best to minimize all kinds of risks and reduce the likelihood of having a baby with Spina bifida pathology to almost zero. We are talking about preventive measures.
One of the main measures to prevent the onset of a diagnosis of spinal cleft in a newborn is careful pregnancy planning. For this, a potential mother and father must have a medical examination before conception, without fail to go to a consultation with a geneticist. A woman is supposed to lead a healthy lifestyle during pregnancy, be wary of taking anticonvulsants. But the intake of folic acid in the required volume, on the contrary, is shown during this period. In many developed countries, this is the main point of the program recommended by the health care organization during pregnancy.
It must be remembered that genetic factors are considered risk factors for the occurrence of pathology; diseases, such as rubella, suffered by a woman during pregnancy; environmental impact - radiation, alcohol, drugs.
Key points
So, answering the question “Spina bifida - what is it?”, We can highlight the main points. Spina bifida is a pathology that occurs in utero during the first weeks of pregnancy. The only way to avoid the disease in the baby is to plan a pregnancy, follow all the necessary instructions from the doctors, expect the mother to lead a healthy lifestyle, and make up for the lack of folic acid in the body.
If the pathology is nevertheless detected, delivery is performed only by caesarean section to exclude injury to the spinal cord when the fetus passes through the birth canal.
For the diagnosis of the disease, there is a whole range of methods - blood analysis, ultrasound diagnostics, amniotic fluid research. If, nevertheless, a violation is identified and the diagnosis is made, surgical intervention is necessary.
An innovative method is the intrauterine elimination of pathology. Surgery is also performed after the baby is born - during the first three days of his life. By the way, suspicions of Spina bifida in a newborn can cause: a hernia on the spine, birthmarks or hollows on one of the skin areas, an unusual hair bundle. Of course, the final diagnosis is established after an additional study - CT, MRI.
Depending on the localization of the affected area of the spine, as well as concomitant functional disorders, the disease is classified into milder and more severe forms.
Mild forms of Spina bifida usually do not lead to severe defects, patients with this diagnosis are socially adapted. In case of severe defects - meningomyelocele - disability cannot be avoided, even if the operation is successful.
The spine clinic is a type of medical institution specializing in medical services to assist patients with central nervous system disorders. Therefore, the diagnosis of Spina bifida is not a sentence. You can and should live with him.