NeuroImages Figure. (A) Postcontrast sagittal T1weighted image: grapefruit-shaped unenhancing cystic lesions in the right thalamomesencephalic region and cerebellar peduncle, with mass effect, consistent with tumefactive perivascular spaces. (B) fluid-attenuated inversion recovery, (C) diffusion-weighted images: bright signal next to the right peduncular cyst, and (D) apparent diffusion coefficient (ADC) map: decreased ADC suggesting associated juxta-cystic acute ischemic lesion. Acute mesencephalic stroke associated with dilated cystic perivascular spaces Jean-Baptiste Pialat, MD; Marc Hermier, MD, PhD; Laurence Lion-François, MD; and François Cotton, MD, PhD, Lyon and Pierre-Bénite, France A 15-year-old girl presented with sudden onset of left hemiparesia and hypoesthesia, with ipsilateral hyperreflexia and dysarthric speech. Serum levels of antinuclear antibodies were moderately increased. No other stroke risk factor or clotting disorDisclosure: The authors report no conflicts of interest. Address correspondence and reprint requests to Dr. Jean-Baptiste Pialat, Service de Radiologie, Hôpital de la Croix Rousse, 103 grande rue de la Croix Rousse, 69317 Lyon cedex 04, France; e-mail: jean-baptiste.pialat@chu-lyon.fr 648 Copyright © 2005 by AAN Enterprises, Inc. der was found. MRI findings one day after stroke onset were consistent with thalamomesencephalic cystic dilation of perivascular spaces (DPVS)1 together with an acute focal ischemic lesion adjacent to a large mesencephalic cyst (figure). No vascular malformation was found. Stroke may have been related to mass effect of focal cystic DPVS compressing penetrating mesencephalic arteries. Alternatively an autoimmune focal necrotizing angiitis could have been present.2 1. Salzman KL, Osborn AG, House P, Jinkins JR, Ditchfield A, Cooper JA, Weller RO. Giant tumefactive perivascular spaces. AJNR Am J Neuroradiol 2005;26:298–305. 2. Homeyer P, Cornu P, Lacomblez L, Chiras J, Derouesne C. A special form of cerebral lacunae: expanding lacunae. J Neurol Neurosurg Psychiatry 1996;61:200–202. Acute mesencephalic stroke associated with dilated cystic perivascular spaces Jean-Baptiste Pialat, Marc Hermier, Laurence Lion-François, et al. Neurology 2005;65;648 DOI 10.1212/01.wnl.0000178167.96418.ff This information is current as of August 22, 2005 Updated Information & Services including high resolution figures, can be found at: http://www.neurology.org/content/65/4/648.full.html References This article cites 2 articles, 2 of which you can access for free at: http://www.neurology.org/content/65/4/648.full.html##ref-list-1 Subspecialty Collections This article, along with others on similar topics, appears in the following collection(s): All Cerebrovascular disease/Stroke http://www.neurology.org//cgi/collection/all_cerebrovascular_disease_ stroke Childhood stroke http://www.neurology.org//cgi/collection/childhood_stroke Infarction http://www.neurology.org//cgi/collection/infarction MRI http://www.neurology.org//cgi/collection/mri Permissions & Licensing Information about reproducing this article in parts (figures,tables) or in its entirety can be found online at: http://www.neurology.org/misc/about.xhtml#permissions Reprints Information about ordering reprints can be found online: http://www.neurology.org/misc/addir.xhtml#reprintsus Neurology ® is the official journal of the American Academy of Neurology. Published continuously since 1951, it is now a weekly with 48 issues per year. Copyright . All rights reserved. Print ISSN: 0028-3878. Online ISSN: 1526-632X.