Perivascular space

Perivascular space
A perivascular space as seen on CT
Anatomical terms of neuroanatomy
CT image showing extensive low attenuation in the right hemispheric white matter due to dilated Type 2 perivascular spaces
Axial fat-suppressed T2-weighted MRI image in the same patient as above demonstrating extensive dilated Type 2 perivascular spaces in the right hemisphere
Perivascular space is depicted in the inset box.

A perivascular space, also known as a Virchow–Robin space, is a fluid-filled space surrounding certain blood vessels in several organs, including the brain,[1] potentially having an immunological function, but more broadly a dispersive role for neural and blood-derived messengers.[2] The brain pia mater is reflected from the surface of the brain onto the surface of blood vessels in the subarachnoid space. In the brain, perivascular cuffs are regions of leukocyte aggregation in the perivascular spaces, usually found in patients with viral encephalitis.

Perivascular spaces vary in dimension according to the type of blood vessel. In the brain where most capillaries have an imperceptible perivascular space, select structures of the brain, such as the circumventricular organs, are notable for having large perivascular spaces surrounding highly permeable capillaries, as observed by microscopy. The median eminence, a brain structure at the base of the hypothalamus, contains capillaries with wide perivascular spaces.[3]

In humans, perivascular spaces surround arteries and veins can usually be seen as areas of dilatation on MRI images. While many normal brains will show a few dilated spaces, an increase in these spaces may correlate with the incidence of several neurodegenerative diseases, making the spaces a topic of research.[4]

  1. ^ Norrving, Bo (2016). "Lacunar Syndromes, Lacunar Infarcts, and Cerebral Small-vessel Disease". Stroke. Elsevier. pp. 449–465.e4. doi:10.1016/b978-0-323-29544-4.00027-x. ISBN 978-0-323-29544-4. Perivascular spaces are fluid-filled spaces that follow a typical course of a vessel penetrating/transversing the brain through gray or white matter.89
  2. ^ Gross PM, Weindl A (1987). "Peering through the windows of the brain (Review)". Journal of Cerebral Blood Flow and Metabolism. 7 (6): 663–72. doi:10.1038/jcbfm.1987.120. PMID 2891718.
  3. ^ Shaver, SW; Pang, JJ; Wainman, DS; Wall, KM; Gross, PM (1992). "Morphology and function of capillary networks in subregions of the rat tuber cinereum". Cell and Tissue Research. 267 (3): 437–48. doi:10.1007/bf00319366. PMID 1571958. S2CID 27789146.
  4. ^ Esiri, MM; Gay, D (1990). "Immunological and neuropathological significance of the Virchow–Robin space". Journal of the Neurological Sciences. 100 (1–2): 3–8. doi:10.1016/0022-510X(90)90004-7. PMID 2089138. S2CID 39929713.