Developmental abnormalities of the nervous system
Intrauterine development of the nervous system (NS) is a very complex process. Under the influence of various factors during pregnancy:
- alcohol consumption,
- drugs,
- smoking,
- genetic disorders,
- infections,
- radiation, etc.
There may be disturbances in its correct formation. As a result, anomalies of the development of the central nervous system arise. There are a lot of anomalies of the nervous system. We will focus on the most common defects that require surgical intervention.
Cranial abnormalities
Craniosynostosis
After birth, the baby’s skull bones and brain are actively growing. By the first year of life, the head size is 90% of the adult size.
The final fusion of the cranial sutures occurs by the age of fourteen. With early fusion of the sutures, there is a discrepancy in the size of the growing brain and the cranial cavity. As a result, the brain is compressed, which leads to severe damage.
Diagnostics – MRI, MSCT.
Treatment is surgical.
Brain developmental abnormalities
Hydrocephalus
As a result, a violation of the circulation of cerebrospinal fluid occurs in the ventricles of the brain, which leads to the development of hydrocephalus – an increase in the size of the ventricles of the brain and compression of the brain. With significant hydrocephalus in children, the size of the head begins to increase.
Diagnostics – MRI, MSCT.
Treatment is surgical, described in the hydrocephalus section .
Arachnoid cysts
As a result, a violation of the circulation of cerebrospinal fluid occurs in the membranes of the brain, which leads to the development of an arachnoid cyst – an increased accumulation of cerebrospinal fluid in a certain area of the brain. With small arachnoid cysts in the head, conservative treatment is possible. If the compression of the brain is pronounced, surgical treatment is indicated.
Diagnostics – MRI, MSCT.
Arnold-Chiari malformation
Arnold-Chiari malformation occurs as a result of a discrepancy between the volume of the posterior fossa cavity and the brain structures located in it (cerebellum, medulla oblongata). This causes part of the cerebellum to descend into the foramen magnum and compresses the medulla oblongata (lower parts of the brainstem) and spinal cord.
There are 4 types of Arnold-Chiari malformation:
- In type 1, only the cerebellar tonsils are prolapsed.
- In type 2, the cerebellar tonsils, the lower part of the cerebellar vermis, and the medulla oblongata prolapse.
- In type 3, there is a critical omission of all brain structures in the posterior cranial fossa.
- In type 4, there is complete underdevelopment of the cerebellum.
Patients complain of pain in the cervicoccipital region, decreased sensitivity and strength in the hands, dizziness, and unsteadiness. As the disease progresses, breathing disorders, swallowing, and inability to move independently appear. The prognosis for types 3 and 4 is unfavorable.
Diagnostics – MRI, MSCT.
Treatment of type 1 is conservative, possibly surgical if symptoms worsen.
Treatment for types 2 and 3 is surgical.
Combined anomalies of the skull and brain bones
Encephalocele
When the sutures of the skull bones do not fuse, a protrusion of the brain (encephalocele) with its membranes under the skin (cerebral hernia) may occur. This is a protrusion of nervous tissue and meninges through a skull defect. The defect is caused by incomplete closure of the cranial vault (cranium bifidum).
Encephalocele usually occurs in the midline and protrudes anywhere along a line from the occiput to the nasal passages, but may be present asymmetrically in the frontal or parietal regions.
A small encephalocele may resemble a cephalohematoma, but X-rays show bony defects in the skull near its base. Hernias are most commonly located in the occipital region and at the base of the nose. Hernias gradually enlarge and can reach enormous sizes.
Diagnostics – MRI, MSCT.
Treatment is surgical.
Developmental abnormalities of the spinal cord and spine
Syringomyelia
As a result of the non-growth of the central canal of the spinal cord, cavities containing cerebrospinal fluid (syringomyelia of the spinal cord) arise, a chronic disease of the central nervous system, in which cavities are formed in the substance of the spinal cord, and sometimes in the medulla oblongata. Syringomyelia is not curable, having begun at a young age, it accompanies the patient throughout his life. As these cysts increase, the compression of the spinal cord from the inside increases.
Patients complain of sensory disturbances in the areas of the trunk and extremities. Then motor disturbances in the extremities join.
Diagnostics – MRI, MSCT.
Treatment is surgical.
Spinal hernias and nonunion of the vertebral arches
Spinal hernias occur due to non-union of the vertebral arches. This is a congenital malformation of the spine and spinal cord, which consists in a defect in the vertebral canal, through which the brain protrudes from it, which sharply disrupts its functions.
This leads to impaired movement of the legs (less often of the arms), incontinence of urine and feces and, consequently, severe disability. With this defect, the contents of the vertebral canal are displaced through the opening in the vertebral arches under the skin. The membranes of the spinal cord, spinal roots, and the spinal cord can be displaced under the skin. The skin over the hernia is thin. If the hernia increases, a rupture of the skin with the outflow of cerebrospinal fluid may occur. This leads to severe infectious complications of the central nervous system.
Diagnostics – MRI, MSCT.
Treatment is surgical.
Neurosurgeon Seledets O.A.
Стаття написана: 22.01.2026
Стаття перевірена медичним спеціалістом: 23.01.2026
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