Expanded perivascular spaces of Virchow Robin, criblyura: what does it mean, causes, pathologies, norm

MRI of the brain is the most important diagnostic tool that captures minimal changes.

Sometimes the study reveals the expansion of the perivascular spaces of Virchow-Robin.

What it is? Normal or pathological? What diseases lead to their expansion, how to decipher the results of MRI and how to make a differential diagnosis.

Perivascular zone, its structure and functions

Virchow-Robin spaces (PVR) are slit-like formations surrounding a cerebral vessel along its path from subarachnoid area inside the brain tissue.

There is still no single point of view about what the perivascular spaces are. Most scientists believe that this is the area between the middle (arachnoid, arachnoid) and inner (pia mater). This area normally surrounds the substance of the brain and, together with the vessels, is carried away into the brain, surrounding them. The subarachnoid area located in the cerebral cortex is called the Virchow-Robin space.

There is no single point of view, only arteries or veins surround the perivascular spaces. It was revealed that they continue to the level of the capillaries.

It is believed that this formation participates in the movement of the cerebrospinal fluid, provides the exchange of necessary substances between the cerebrospinal fluid and neurons.

Another function is to isolate intravascular blood from brain tissue. Blood contains a number of toxic substances that normally should not enter the brain substrate due to the presence blood-brain barrier. Additionally, toxins are absorbed inside the perivascular area.

Another challenge is immune regulation.

When the expansion of the perivascular spaces is the norm

It is possible to see the perivascular canals only with the help of MRI.

Virchow Robin spaces are often not visualized even on MRI scans due to their small area. The resolution of the tomograph matters. Size up to 2 mm is normal and occurs in all people.

The enlarged perivascular spaces are called cribs.

Their increase does not always indicate pathology. The mechanism of their expansion is still being studied. This is possible due to inflammation of the vessel wall, when the latter becomes thinner and more permeable. The escaping liquid leads to the expansion of the criblur. Another reason is the violation of the flow of the cerebrospinal fluid, and another lengthening of blood vessels.

Scientists and medical practitioners have not come to a consensus about what is considered pathology and what is not. As a rule, fixing spaces on MRI images in people of an older age group is a variant of the norm.

Often cribs in the brain are found in children in the first year of life.

They are usually localized in three areas:

1. Along the course of the lenticular arteries that supply blood basal ganglia – caudate nucleus, inner capsule, fence.
2. Along the course of certain arteries that enter the brain from the outside, and not like most branches of the carotid and vertebral arteries from the internal.
3. In the course of the vessels supplying midbrain (posterior thalamoperforating and median mesencephalothalamic arteries).

Appear symmetrically. Most often, the expansion of the perivascular spaces occurs in the region of the lower basal structures and very rarely in cerebellum. As a rule, the dimensions do not exceed 5 mm.

CSF flows in the perivascular canals, therefore, on MRI, the cribs have the same plane with the latter and look isodense.

There are 2 projections in which MRI images of the brain are usually taken: frontal and axial. In the first case, the expanded spaces look like stripes, and in the second they take a round or oval shape, corresponding to the section.

The use of various MRI modes, especially T-2, helps in diagnosis. In this mode Virchow-Robin spaces do not have a darker rim around the filled area, which indicates that this is precisely part of the subarachnoid membrane, and not the wall of the cavity, focus or neoplasms.

Expanded spaces in pathology

Localization and intensity of the MRI signal will help to distinguish between pathology or age norm.

If the kriblyura is visualized in an atypical place and there is an asymmetric picture, then most likely we are talking about a disease.

There are several reasons for true expansion.

Psychiatric illnesses

This connection is still being studied.

Cryptococcosis

It is a fungal disease that occurs in people with immunodeficiency. Most often occurs in HIV-infected people. In this case, fungal spores can be localized inside the perivascular spaces, causing them to expand. Such clusters are called gelatinous pseudocysts. They differ from normal extended spaces in that they remain hyperdense in FLAIR mode.

The MRI picture of the concomitant also helps to identify the disease. meningitis, hydrocephalus and the presence of foci of cryptococcosis in the substance of the brain.

Treatment is with antifungal drugs.

Mucopolysaccharidosis

This is a congenital metabolic disease in which the decomposition of glycosoaminoglycans is impaired. Excess substances accumulate, forming criblures. In the pictures, they look like lattice. Also visualized hyperintense white matter, which helps to distinguish pathology from the norm.

Since the disease is based on an enzyme deficiency, the goal of therapy is their synthetic replacement: Aldurazim, Elapraza.

Differential diagnosis

An important point is the differential diagnosis of expanded Virchow-Robin spaces and other cerebral pathologies.

Lacunar infarction

Criblyurs, with their large size and merging with each other, can be taken for lacunar infarction. Often confusion arises from the same localization - in the area of ​​the basal ganglia.

The difference is that with a heart attack, the lesions, as a rule, exceed the size of 5 mm. Also, the lesions are asymmetrical. An experienced radiologist will be able to distinguish using different imaging modes: T1, T2, FLAIR.

Differential diagnosis between enlarged perivascular space and stroke is important because if left untreated, a more extensive cerebral catastrophe with the formation of a neurological deficit.

Stroke treatment carried out under the supervision of a neurologist.

Cystic periventricular leukomalacia

This disease occurs in premature babies due to impaired breathing. The brain suffers from oxygen deficiency and strokes appear along the vessels, which are very similar to the Virchow-Robin spaces.

In most cases, the disease does not require therapy. If the cysts become large, they can be surgically removed.

Multiple sclerosis

Hotbeds of this demyelinating disease can be located in any part of the brain, including around the cortical vessels.

A distinctive feature is that in multiple sclerosis, the lesions come from the lateral ventricles, forming the so-called "Dawson's fingers".

When a clinic of multiple sclerosis is identified, PITRS therapy is prescribed.

Cystic tumors

Often, enlarged perivascular spaces may resemble cystic neoplasm. In this case, the cyst has a different intensity inside the neoplasm and accumulates contrast. In this case, you need to contact an oncologist and neurosurgeon.

Interesting Facts

The perivascular spaces are named after two scientists. However, as is often the case, another person first discovered this area. This was done in 1843 by Durand Fardel.

Only 10 years later, the German scientist Rudolf Virchow described in detail the structure of this area. This fact is surprising considering that a conventional microscope was used for the study.

A few years later, his French colleague clarified that this is not just a gap, but a channel inside which a cerebral vessel passes.