Malformations of the brain

Septooptic dysplasia (de Morsier's syndrome)

Septooptic dysplasia (de Morsier syndrome) is a defect in the development of the anterior part of the brain that develops near the end of the first month of gestation and includes hypoplasia of the optic nerve, the absence of a septum between the anterior sections of the two lateral ventricles, and the inadequacy of the pituitary hormones. Despite the fact that the causes can be multiple, in some patients with septooptic dysplasia, anomalies of one specific gene (HESX1) were detected.

Symptoms may include reduced visual acuity of one or both eyes, nystagmus, strabismus and endocrine dysfunction (including growth hormone deficiency, hypothyroidism, adrenal insufficiency, diabetes insipidus and hypogonadism). Cramps may develop. Despite the fact that some children have normal intelligence, others have learning disabilities, mental retardation, cerebral palsy or other types of developmental delay. The diagnosis is based on MRI. All children in the detection of this disease should be examined for endocrine dysfunction and developmental disorders. Treatment is supportive.

Anencephaly

Anencephaly is the absence of the cerebral hemispheres. The missing brain is sometimes replaced by an incorrectly formed cystic neural tissue, which can be nude or covered skin. Parts of the brainstem or spinal cord may be absent or be formed incorrectly. A child is born dead or dies within a few days or weeks. Treatment is supportive.

[1], [2], [3], [4], [5], [6], [7]

Encephalocele

Encephalocele is a protrusion of the nervous tissue and meninges through a defect in the skull. The formation of a defect is associated with incomplete closure of the cranium (cranium bifidum). Encephalocele usually occurs along the midline and protrusion occurs anywhere from the occiput to the nasal apertures, but it can be asymmetric in the frontal and parietal areas. A slight protrusion may resemble a cephalogram, but on the roentgenogram there is a defect in the skull at its base. Often with encephalocele, hydrocephalus is noted. Approximately 50% of children have other congenital anomalies.

The prognosis, which depends on the location and size of the protrusion, is usually good. In most cases, encephalocele can be successfully operated. Even with a large size, the protrusion, as a rule, contains predominantly ectopic nerve tissue, which can be removed without impairing the functionality. If the encephalocele is combined with other severe developmental anomalies, the decision to perform the operation may be more difficult.

[8], [9], [10], [11], [12],

Incorrectly formed cerebral hemispheres

The hemispheres of the brain can be large, small, or asymmetric; Cortis may be absent, unusually enlarged or numerous and small; a microscopic examination of a normal brain looking may show disorganization of the normal arrangement of neurons. Microcephaly, moderate or severe retardation of motor and mental development and epilepsy are often noted with these defects. Treatment is supportive, includes anticonvulsant drugs if necessary to control convulsive syndrome.

Holoproencephalus

Goloprosencephaly develops when segmentation and divergence does not occur in the embryonic proencephalon (forebrain). The anterior middle brain, skull and face are irregularly formed. This developmental defect can be caused by defects in the gene sonic hedgehog ("sonic hedgehog"). In severe lesions, the fetus may die before birth. Treatment is supportive.

Lysencephaly

Lysencephaly consists of an abnormally thickened cortex, reduced or absent differentiation into layers, and diffuse heterotopy of neurons. The reason is the violation of migration of neurons, the process by which immature neurons connect with radial glia and move from the place of the bookmark near the ventricles to the surface of the brain. Several defects of individual genes may be the cause of this developmental malformation (eg, LIS1). In children with this developmental malformation, mental retardation, muscle spasms and convulsions are noted. The treatment is supportive, however many children die before the age of two.

Polymicropathy

Polymicropathy, in which the convolutions are small and there are a large number, is considered a consequence of brain damage between the 17th and 26th weeks of gestation. In this case, there may be a delay in mental development and convulsions. Treatment is supportive.

Porencephaly

Pornecephaly is a cyst or cavity in the cerebral hemisphere that communicates with the ventricle. Can develop pre and postnatal. This defect can be caused by malformation, an inflammatory process or a vascular complication, for example intraventricular hemorrhage with spreading to the parenchyma. The results of a neurological examination, as a rule, differ from normal. The diagnosis is confirmed by CT, MRI or ultrasound of the brain. Rarely with porencephaly there is a progressive hydrocephalus. The forecast is different; a small number of patients develop only minimal signs from the nervous system, they have normal intelligence. Treatment is supportive.

Hydranencephaly

Hydraencephaly is the extreme form of panthencephaly, in which the cerebral hemispheres are almost completely absent. Usually the cerebellum and brain stem are normally formed, the basal ganglia are intact. Cerebrums, bones and skin above the cranial vault are normal. Often hydranencephaly is diagnosed prenatally by ultrasound. The results of the neurological examination, as a rule, differ from normal, the child develops with impairments. Outside, the head may look normal, but with diaphanoscopy, the light shines completely. CT or ultrasound confirm the diagnosis. Treatment is supportive, with shunting with excessive growth of head size.

Shizentsefaliya

Shizentsefaliya, which can be classified as one of the forms of porencephaly, is the result of the formation of abnormal convolutions or clefts in the cerebral hemispheres. Unlike porentsefalia, which is believed to be a consequence of brain damage, it is thought that schizencephaly is a defect in the migration of neurons and, thus, a true malformation of the brain. Treatment is supportive.