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Neuroradiology Case of the Week

Case 417

June 2009

Ashwani K. Sharma, MD, and P-L Westesson, MD, PhD, DDS

Clinical Presentation: Patient is a 22-year-old male with mental status changes.

Imaging Findings: Virchow-Robin (VR) spaces surround the walls of vessels as they course from the subarachnoid space through the brain parenchyma. These cystic spaces are present at characteristic sites. Most common locations for VR spaces is around the anterior commissure, deep white matter and midbrain. Other less common locations include thalami, cerebellum, corpus callosum, and cingulated gyrus. Usually these are bilateral but less commonly can be unilateral.
     On MR imaging these spaces follow CSF signal characteristic and density.

Diagnosis: Virchow Robin spaces (perivascular spaces)

Discussion: The Virchow-Robin (VR) space is named after Rudolf Virchow (German pathologist, 1821–1902) [1] and Charles Philippe Robin (French anatomist, 1821–1885) [2]. VR spaces, or perivascular spaces, surround the walls of vessels as they course from the subarachnoid space through the brain parenchyma. With advancing age, VR spaces are found with increasing frequency and larger apparent sizes. On imaging, VR spaces follow cerebrospinal fluid imaging characteristics.

Locations and Morphology: The first type (type I) appears along the lenticulostriate arteries entering the basal ganglia through the anterior perforated substance [3,4].

The second type (type II) can be found along the path of the perforating medullary arteries as they enter the cortical gray matter over the high convexities and extend into the white matter [3,4].

The third type (type III) appears in the midbrain. They are mainly located between the cerebral peduncles in the axial plane and correspond to the level of the tentorial margin as seen in coronal sections. In the upper midbrain, where the VR spaces are visible at the mesencephalodiencephalic junction, they appear along the posterior (interpeduncular) thalamoperforating artery or the paramedian mesencephalothalamic artery and short and long circumferential arteries originating from the upper basilar artery or proximal posterior cerebral artery [5,6].

     It is reported that clusters of type II enlarged VR spaces may predominantly involve one hemisphere [7]. There are even reports that describe the solely unilateral appearance of enlarged VR spaces in the high convexity [8,9]. Most common locations for VR spaces is around the anterior commissure, deep white matter and midbrain. Other less common locations include thalami, cerebellum, corpus callosum, and cingulated gyrus. Usually these are bilateral but less commonly can be unilateral.
     Whereas Jungreis et al. reported that the lenticulostriate perivascular spaces did not correlate with advancing age [10], Heier et al. concluded that the larger perivascular spaces were another phenomenon of the aging brain [3].
     Knowledge of the signal intensity characteristics and locations of VR spaces helps differentiate them from various pathologic conditions, including lacunar infarctions, cystic periventricular leukomalacia, multiple sclerosis, cryptococcosis, mucopolysaccharidoses, cystic neoplasms, neurocysticercosis, arachnoid cysts, and neuroepithelial cysts [12].

References:

1. Virchow R. Ueber die Erweiterung kleinerer Gefaesse. Archiv Pathol Anat Physiol Klin Med 1851; 3:427–462.
2. Robin C. Recherches sur quelques particularités de la structure des capillaires de l’encephale. J Physiol Homme Anim 1859;2:537–548.
3. Heier LA, Bauer CJ, Schwartz L, Zimmerman RD, Morgello S, Deck MD. Large Virchow-Robin spaces: MR-clinical correlation. AJNR Am J Neuroradiol. 1989 Sep-Oct;10(5):929-36. [PubMed]
4. Jungreis CA, Kanal E, Hirsch WL, Martinez AJ, Moossy J. Normal perivascular spaces mimicking lacunar infarction: MR imaging. Radiology. 1988 Oct;169(1):101-4. [PubMed]
5. Elster AD, Richardson DN. Focal high signal on MR scans of the midbrain caused by enlarged perivascular spaces: MR-pathologic correlation. AJR Am J Roentgenol. 1991 Jan;156(1):157-60. [PubMed]
6. Duvernoy HM. Human brainstem vessels. Berlin: Springer-Verlag, 1978:16–66.
7. Ogawa T, Okudera T, Fukasawa H, et al. Unusual widening of Virchow-Robin spaces: MR appearance. AJNR Am J Neuroradiol. 1995 Jun-Jul;16(6):1238-42. [PubMed]
8. Sawada M, Nishi S, Hashimoto N. Unilateral appearance of markedly dilated Virchow-Robin spaces. Clin Radiol. 1999 May;54(5):334-6. [PubMed]
9. Shiratori K, Mrowka M, Toussaint A, Spalke G, Bien S. Extreme, unilateral widening of Virchow-Robin spaces: case report. Neuroradiology. 2002 Dec;44(12):990-2. [PubMed]
10. Jungreis CA, Kanal E, Hirsch WL, Martinez AJ, Moossy J. Normal perivascular spaces mimicking lacunar infarction: MR imaging. Radiology. 1988 Oct;169(1):101-4. [PubMed]
11. Kwee RM, Kwee TC. Virchow-Robin spaces at MR imaging. Radiographics. 2007 Jul-Aug;27(4):1071-86. [PubMed]