Polymicrogyria: causes, symptoms and effects

Normally, during the normal development of the brain, a series of folds or coils form which serve to make the surface of the brain take up less space and fit inside the skull. Like any other organ, the brain also suffers from deformities. An example of this is polymicrogyria, which affects the morphology of the folds of the cerebral cortex..

It is a disease that causes severe neurological symptoms due to malformations that occur during fetal development. Let’s briefly take a look at the type of training issues we encounter in polymicrogyria, its cause, and what can be done with those who suffer from it.

What is polymicrogyria

The etymology of the word poly- (multiple) micro (petite) -giria (folds) clearly indicates: it is a defect of morphology in which we observe a greater number of smaller folds. This genetic defect in the cortex can be clearly observed with diagnostic diagnostic tests like magnetic resonance imaging (MRI). These images show how the cortex is thicker and more intense, indicating a higher density, and how the folds form superficially, different from those of a normal brain.

There are different forms of polymicrogyria, depending on the most severe. When it affects only part of the brain, it is called unilateral. It is called bilateral, however, when both hemispheres are affected. The nomenclature refers not only to symmetry, but also to the number of areas of the brain affected. Thus, a brain with only one affected area would suffer from focal polymicrogyria, compared to generalized polymicrogyria when it affects almost all or all of the cortex.

Polymicrogyria models have a predilection for certain lobes over others. The most frequently affected lobes are the frontal (70%), followed by the parietal (63%) then the temporal (18%). Only a small part (7%) has the occipital lobes affected. It also seems to have a tendency to deform the lateral fissures which more often separate the frontal and parietal lobes from the temporal lobes (60%).

    Signs and symptoms

    While the focal and unilateral forms are generally more problematic than the drug-controllable seizures, when they are bilateral, the severity of symptoms skyrockets. Some symptoms include:

    • epilepsy
    • Developmental delay
    • strabismus
    • Speech and swallowing problems
    • Muscle weakness or paralysis

    Global polymicrogyria impairments are accompanied by profound mental retardation, severe movement problems, Cerebral palsy and seizures that cannot be controlled with medication. Therefore, while milder forms of polymicrogyria allow for a fairly long life expectancy, people born with severe impairment die at a very young age due to complications from the disease.

    Often, polymicrogyria does not occur on its own or on its own, but in conjunction with other syndromes such as:

    • Variants of Adams-Oliver syndrome
    • Arima syndrome
    • Galoway-Mowat syndrome
    • Delleman syndrome
    • Zellweger syndrome
    • Fukuyama muscular dystrophy

    the causes

    In most cases, the cause is unknown. There is a percentage of cases that occur because the mother suffers from an intrauterine infection during pregnancy. Some viruses linked to the development of polymicrogyria are cytomegalovirus, toxoplasmosis, Varicella and syphilis viruses.

    Hereditary causes include both chromosomal syndromes, that is, those that affect multiple genes at the same time, and syndromes of a single gene. There are a multitude of genetic disorders that alter the way the brain is formed. Therefore, many genetic diseases are accompanied by polymicrogyria among other manifestations.

    The GPR56 gene has been identified as one of the main causes of polymicrogyria in its global and bilateral version. In one study, it was found that all of the patients examined underwent a change in this gene, which resulted in damage to the central nervous system. This gene is known to be heavily involved in the formation and development of the fetal cerebral cortex during pregnancy.

    Therefore, it is important that parents who suffer or are at risk for polymicrogyria are made aware of the hypothetical risk of transmitting their disease to the child and determine through a genetic study what is the true likelihood of occurrence before the onset of the disease. gestation.

    Patient management after diagnosis

    After diagnostic imaging, it will be necessary to do a full assessment in areas affected by polymicrogyria. Pediatricians, neurologists, physiotherapists and occupational therapists will have to intervene to assess the risk of developmental delay, intellectual disability or even cerebral palsy. In this sense, special educational needs should be indicated so that the patient can learn at the speed that his disease allows. Speech will be assessed in those who have the affected lateral fissure, vision and hearing.

    Symptoms will be treated with physiotherapy, drug intervention with anti-epileptics, orthopedic products, and surgery for patients with stiffness due to muscle spasticity. When there are speech problems, speech therapy and professional intervention will be performed.

    Finally, parenting training is a cornerstone of symptom management. They will need to be trained in issues related to how crises occur and what to do in the event of death. In addition, supportive measures can be used to prevent the onset of joint problems or pressure ulcers due to the patient sitting in the same posture for too long.

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