Journal of Neuro-Ophthalmology, March 2014, Volume 34, Issue 1

Restricted Diffusion in Isolated Superior Ophthalmic Vein Thrombosis

The University of Texas Medical School at Houston, Houston, Texas, Department of Ophthalmology, The University of Iowa Hospitals and Clinics, Iowa City, Iowa, Department of Ophthalmology, The University of Texas Medical Branch, Galveston, Texas, [e-mail] Supported in part by an unrestricted grant from Research to Prevent Blindness (RPB). The authors report no conflicts of interest. REFERENCES 1. Bodanapally UK, Kathirkamanathan S, Geraymovych E, Mirvis SE, Choi AY, McMillan AB, Zhuo J, Shin RK. Diagnosis of traumatic optic neuropathy: application of diffusion tensor magnetic resonance imaging. J Neuroophthalmol 2013;33:128-133. 2. Istoc A, Habas C, Iba-Zizen MT, Nguyen TH, Abanou A, Yoshida M, Bellinger L, Le Gargasson JF, Cabanis EA. Value of the functional neural tractography in the reconstruction of the visual pathways in DTMRI [in French]. J Fr Ophtalmol 2010;33:670-679. 3. Kier EL, Staib LH, Davis LM, Bronen RA. MR imaging of the temporal stem: anatomic dissection tractography of the uncinate fasciculus, inferior occiptofrontal fasciculas, and Meyer's Loop of the optic radiation. AJNR Am J Neuroradiol 2004;25:677-691. 4. Hofer S, Karaus A, Frahm J. Reconstruction and dissection of the entire human visual pathway using diffusion tensor MRI. Front Neuroanat 2010;4:15. 5. Wang R, Benner T, Sorensen AG, Wedeen VJ. Diffusion Toolkit: a software package for diffusion imaging data processing and tractography. Proc Intl Soc Mag Reson Med 2007;15:3720. Restricted Diffusion in Isolated Superior Ophthalmic Vein Thrombosis Superior ophthalmic vein (SOV) thrombosis is a rare disease entity characterized by rapidly progressive orbital symptoms, including periorbital edema, chemosis, propto-sis, and ophthalmoplegia. It may be isolated or accompanied by cavernous sinus thrombosis. Parmar et al (1) reported the value of diffusion-weighted imaging (DWI) in establishing this diagnosis, and we describe our experience with this disorder. FIG. 1. Orbital magnetic resonance imaging. Postcontrast T1 axial (A) and coronal (B) scans show diffuse enhancement of preseptal and retrobulbar regions of the left orbit, and absence of normal enhancement within the left superior ophthalmic vein (arrows). Diffusion-weighted imaging (C) reveals hyperintense signal in the left superior ophthalmic vein (arrows) and apparent diffusion coefficient map (D) shows a corresponding hypointense signal (arrow) confirming restricted diffusion. 98 Letters to the Editor: J Neuro-Ophthalmol 2014; 34: 95-104 Letters to the Editor Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. A 53-year-old man presented with headache and left eye swelling for 6 days. Examination revealed proptosis, eyelid edema, and weakness of depression in the left eye and a dilated poorly reactive left pupil. Orbital magnetic resonance imaging performed 6 days after symptom onset, showed diffuse left orbital enhancement and an intra-luminal filling defect within the left SOV (Fig. 1A, B). There was no abnormal signal or filling defect within the cavernous sinus. DWI disclosed restricted diffusion in the left SOV (Figs. 1C & 1D) consistent with thrombosis. Over the next 7 days, the patient was treated with intravenous broad-spectrum antibiotics. He showed marked improve-ment of periorbital swelling, and limitation of left eye move-ment gradually resolved. Although the utility of orbital DWI is limited due to inhomogeneous tissues that produce susceptibility artifacts, there have been 3 reported cases of restricted diffusion in SOV thrombosis reflecting the presence of intravascular clot (1-3). Restricted diffusion corresponding to the presence of intravascular clots has been described in vertebral artery dissection and cerebral venous thrombosis, but the fre-quency and evolution of diffusion changes are variable (4-6). Our patient showed high signal intensity on DWI on the 6th day after the onset of symptoms, which corre-sponds to the early subacute (3-7 days) stage of intrapar-enchymal hematoma. However, previous case reports described restricted diffusion of the thrombosed SOV in patients with different time periods of acute (1-3 days) or chronic (.14 days) stages (1,2). These findings suggest that the diffusion changes of intravascular clots differ from that of intraparenchymal hematoma that mainly shows hyperin-tense signal at the hyperacute (,1 day) stage (7). Since SOV thrombosis is a potentially life-threatening condition, prompt recognition is important for effective treatment. DWI may provide an important clue as to the presence of intravascular clots according to the stage of thrombus formation in SOV thrombosis. Jae-Hwan Choi, MD Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Sience and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea Jae-Ho Jung, MD Department of Ophthalmology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea Seung Kuk Baik, MD Department of Radiology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea Kyung-Pil Park, MD Department of Neurology, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea Kwang-Dong Choi, MD Department of Neurology, Pusan National University Hospital, Pusan National University School of Medicine and Biomedical Research Institute, Busan, Korea [e-mail] The authors report no conflicts of interest. REFERENCES 1. Parmar H, Gandhi D, Mukherji SK, Trobe JD. Restricted diffusion in the superior ophthalmic vein and cavernous sinus in a case of cavernous sinus thrombosis. J Neuroophthalmol 2009;29: 16-20. 2. Pendharkar HS, Gupta AK, Bodhey N, Nair M. Diffusion restriction in thrombosed superior ophthalmic veins: two cases of diverse etiology and literature review. J Radiol Case Rep 2011;5:8-16. 3. De Lott LB, Trobe JD, Parmar H. Restricted diffusion of the superior and inferior ophthalmic veins in cavernous sinus thrombosis. J Neuroophthalmol 2013. [Epub ahead of print]. 4. Choi KD, Jo JW, Park KP, Kim JS, Lee TH, Kim HJ, Jung DS. Diffusion-weighted imaging of intramural hematoma in vertebral artery dissection. J Neurol Sci 2007;253:81-84. 5. Lövblad KO, Bassetti C, Schneider J, Guzman R, El-Koussy M, Remonda L, Schroth G. Diffusion-weighted MR in cerebral venous thrombosis. Cerebrovasc Dis 2001;11:169-176. 6. Favrole P, Guichard JP, Crassard I, Bousser MG, Chabriat H. Diffusion-weighted imaging of intravascular clots in cerebral venous thrombosis. Stroke. 2004;35:99-103. 7. Atlas SW, DuBois P, Singer MB, Lu D. Diffusion measurements in intracranial hematomas: implications for MR imaging of acute stroke. AJNR Am J Neuroradiol 2000;21:1190-1194. Letters to the Editor: J Neuro-Ophthalmol 2014; 34: 95-104 99 Letters to the Editor Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.