When you think of a brain, you’ll probably get the image of a bent or bent organ. There’s a reason these folds. His absence, as in pachygiria, can have serious consequences.
Pachygiria is a congenital malformation of the cerebral cortex, the result of poor neural migration, which causes abnormally thick convolutions.
- In general.
- Children with pachygiria tend to have a variable degree of intellectual disability.
- Developmental delays.
- And epileptic disorders as major symptoms.
What is the cause of pachygiria?How is it diagnosed and what symptoms do you have,, can it be treated?Read on for answers.
The cerebral cortex covers the surface of both brain hemispheres and has a fully bent structure. This allows you to have a large surface area in a small space compared to the surface of a smooth brain of the same size.
Thus, on the surface of the crust we can distinguish the cracks, which are grooves of variable size, and the convolutions, which are bumps located between the cracks.
The cortex consists mainly of glial cells and neural bodies and is organized into six layers in which neurons are precisely arranged.
Pachygiria is a malformation belonging to the family of lisencephaly (disorders characterized by the smoothing of the cortical surface), which is between actia, total absence of convolutions and polymicrogiria (malformation of the cortex that has excessive convolutions).
Pachygiria is a severe congenital malformation (with a very high mortality rate) in which the organization of neurons in the cerebral cortex and its structure is altered, making the cerebral cortex thinner than normal, as some of the six layers that make up the cerebral cortex are missing or their cells are not well organized.
In addition, the main feature is that the bark does not have very pronounced cracks, in addition to thicker and wider convolutions than normal, which makes the bark smoother and less ‘bent’.
In most cases, children with pachygiria have the following symptomatic triad: intellectual disability, seizures, and severe developmental disorders; however, they may have a wide variety of symptoms, which we’ll see below:
The absence of facial or physical characteristics can make diagnosis difficult, so diagnosis is based on a clinical examination of neuroimaging symptoms and techniques that allow a detailed evaluation of the cerebral cortex.
CT (calculated axial tomography) provides images of the brain with high spatial resolution, however, bark malformations are easier to visualize in vivo, so MRI is more useful because it offers greater contrast and better differentiation of gray and white matter regions.
Thickened brain convolutions with few surface cracks are visible in the images, as well as incomplete development of the Sylvius crack.
Pachygiria is caused by an interruption in the fetal neural migration process. This failure can be caused by environmental influences or genetic changes, which we will discuss shortly.
Neural migration occurs between the seventh and twentieth weeks of gestation, the purpose of this migration is the formation of the six layers that make up the cortex; however, in pachygiria, only four of the six layers are present (which makes the cortex thinner than normal). ).
In simple terms, in a brain with pachygiria, the first layer (molecular or plexiform) is present and is the same as in a normal brain, but the second, third and fourth layers have fewer cells than in a healthy brain, in addition to a finer structure.
As mentioned, this change in neural migration can be caused by environmental influences, such as exposure to certain substances or elements (radiation, alcohol, mercury?).
As for the genetic alterations responsible for pachygiria, they are complex to treat in this article, however, it should be noted that the most common genetic alterations that cause pachygiria are usually related to the X chromosome and chromosome 17. The LIS1 gene appears to be the cause of smoothencephaly.
As with almost all rare diseases, there is still no treatment that is simply symptomatic, in this case the administration of antiepileptic drugs for the treatment of seizures is essential.
As mentioned, this is a serious malformation that results in the death of most children born with pachygiria; However, when this malformation does not reach the cortex, it is consistent with the life and development of the disease will depend on the affected malformation region.
In case of survival, collaboration between different professionals will be essential, from physiotherapists who attend motor disorders such as hypotonia, to special education teachers who adapt programs for the education of the child.
There is also, of course, the cooperation of doctors, nurses, occupational therapists and psychologists to improve children’s quality of life and promote their autonomy as much as possible.