Tumefactive Perivascular Spaces Causing Obstructive Hydrocephalus.

Abstract

HomeRadiologyVol. 307, No. 1 PreviousNext Reviews and CommentaryFree AccessImages in RadiologyTumefactive Perivascular Spaces Causing Obstructive HydrocephalusDaniel D. L. Loh, Saravana Kumar Swaminathan Daniel D. L. Loh, Saravana Kumar Swaminathan Author AffiliationsFrom the Departments of Neurosurgery (D.D.L.L.) and Neuroradiology (S.K.S.), National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433.Address correspondence to S.K.S. (email: [email protected]).Daniel D. L. LohSaravana Kumar Swaminathan Published Online:Dec 6 2022https://doi.org/10.1148/radiol.221724MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack CitationsPermissionsReprints ShareShare onFacebookTwitterLinked In A 71-year-old woman presented with a 3-week history of intermittent dizziness. Clinical examination was unremarkable. Presentation MRI (Figure) demonstrated a cluster of closely spaced, well-demarcated, variably sized intraparenchymal cysts centered in the midbrain and thalami. No associated solid component, enhancement, or perilesional edema was detected. The cyst contents were isointense to cerebrospinal fluid on all sequences. Associated mass effect resulted in obstructive hydrocephalus from compression of the cerebral aqueduct with lateral and third ventricular dilatation. A diagnosis of tumefactive perivascular spaces was made based on these imaging appearances. The hydrocephalus and dizziness resolved after ventriculoperitoneal shunting.Images in a 71-year-old woman who presented with a 3-week history of intermittent dizziness. (A) Axial MRI T2-weighted and (B) postcontrast T1-weighted scans demonstrate a cluster of well-demarcated, variably sized cysts (short arrows) within the midbrain and thalami that were isointense to cerebrospinal fluids, causing obstructive hydrocephalus (long arrows demonstrate compressed cerebral aqueduct). There was no associated enhancement, restricted diffusion, or calcification. The findings were diagnostic for tumefactive perivascular spaces, causing obstructive hydrocephalus.Download as PowerPointOpen in Image Viewer Perivascular spaces are intraparenchymal, pial-lined, interstitial fluid-filled structures that follow the penetrating arteries but do not directly communicate with the subarachnoid space. When large (>1.5 cm), they exert significant mass effect and are called tumefactive perivascular spaces (1). The mesencephalothalamic region is one of the most common locations of giant (or tumefactive) perivascular spaces (1). While the differential diagnosis includes cystic neoplasms, infarcts, and infections, these other pathologic conditions are all distinct from this entity with MRI (1–3).Disclosures of conflicts of interest: D.D.L.L. No relevant relationships. S.K.S. Patents planned, issued, or pending with National Neuroscience Institute.