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Show Restricted Diffusion of the Superior and Inferior Ophthalmic Veins in Cavernous Sinus Thrombosis Lindsey B. De Lott, MD, Jonathan D. Trobe, MD, Hemant Parmar, MD Abstract: Two previous reports have described restricted diffusion in thrombosed superior ophthalmic veins (SOVs) in patients with cavernous sinus thrombosis (CST). We report a patient who displayed restricted diffusion in both the SOV and inferior ophthalmic vein in CST consequent to a masticator space abscess. The orbital vascular imaging findings added support to the cavernous sinus findings in making the diagnosis of CST. Diffusion-weighted imaging of the orbit is a valuable asset in this setting. Journal of Neuro-Ophthalmology 2013;33:268-270 doi: 10.1097/01.wno.0000434279.57700.3c © 2013 by North American Neuro-Ophthalmology Society A59-year-old man presented to the emergency room with several weeks of pain in the left jaw exacerbated by chewing and talking. Four days earlier, he had noticed progressive swelling of the left cheek and neck followed by a persistent severe frontal headache. Temperature was 39.1°C, heart rate was 111 beats per minute, and blood pressure was 106/52 mm Hg. There was a marked left facial swelling without erythema. Purulent fluid could be expressed from the gingiva upon palpation of the left cheek, suggesting an abscess. The leukocyte count was 34.3 K/mm3 with 86% neu-trophils. The platelet count was 417 K/mm3. Neck com-puted tomography (CT) showed extensive dental and periodontal disease with multiple abscesses in the left mas-ticator space involving the left masseter and lateral and medial pterygoid muscles (Fig. 1A). Incision and drainage of the abscesses was performed. Vancomycin, clindamycin, and levofloxacin were instituted. The following day he reported reduced vision in the right eye and double vision on left gaze and when reading. Ophthalmologic examination revealed a best-corrected visual acuity of 20/60 in the right eye and 20/20 in the left eye. Pupils constricted normally without an afferent pupillary defect. There were no abnormalities of the left eye. There were 3 mm of right upper eyelid ptosis with upper and lower eyelid edema and 3 mm of right eye proptosis as FIG. 1. Computed tomography (CT). A. Axial contrast-enhanced neck CT shows multiple abscesses in the left masticator space involving the left masseter and medial pterygoids (arrows). B. A more rostral image shows lateral bulging of both cavernous sinuses (arrows). There is enhancement of the intracavernous carotid arteries as well as the superior sagittal sinus (arrowhead), but none of the cavernous sinuses, suggestive of thrombosis. Departments of Ophthalmology and Visual Sciences (LBL, JDT), Neurology (LBL, JDT), and Radiology (HP), University of Michigan, Ann Arbor, Michigan. Disclosures: The authors report no conflicts of interest. Address correspondence to Jonathan D. Trobe, MD, 1000 Wall Street, Ann Arbor, MI 48105; E-mail: jdtrobe@med.umich.edu 268 De Lott et al: J Neuro-Ophthalmol 2013; 33: 268-270 Photo Essay Section Editor: Timothy J. McCulley, MD Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. FIG. 2. Magnetic resonance imaging (MRI). A. Contrast-enhanced axial T1 MRI of the orbits with fat suppression shows enhancement in the right orbital fat, optic nerve sheath, and extraocular muscles. B. Contrasted axial T1 scan shows bulging of the lateral walls of the cavernous sinuses (arrows) and inhomogeneous enhancement of each sinus. C. Contrasted coronal T1 images with fat suppression reveal enhancement of the right orbital fat and optic nerve sheath. The right superior (SOV) and inferior ophthalmic veins (IOV) fail to opacify (arrows), compared with normal filling of these veins in the left orbit (ar-rowheads). Diffusion-weighted imaging (DWI) shows increased signal in the right IOV (D) and right SOV (E, F). G, H, I. Restricted diffusion is confirmed on corresponding ADC maps. De Lott et al: J Neuro-Ophthalmol 2013; 33: 268-270 269 Photo Essay Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. measured with the Hertel exophthalmometer. The right eye was tender to palpation. Its conjunctiva was hyperemic and edematous. Abduction was 50% of normal, and supra-duction, infraduction, and adduction were 25% of normal. Intraocular pressures were 15 mm Hg in the right eye and 9 mm Hg in the left eye. Ophthalmoscopy was normal. Neurologic examination was normal. As the ophthalmic findings suggested the possibility of a cavernous sinus lesion, the neck CT was rereviewed with more attention to the cavernous sinus. The CT study was performed using a split-bolus technique (50 mL of contrast bolus followed by a 75 mL of contrast bolus 90 seconds later) according to our standard protocol, as some neck tumors demonstrate late contrast enhancement. Both arterial and venous phases were captured. There was nonopacification and lateral bulging of both cavernous sinuses (Fig. 1B). A dedicated contrast-enhanced orbital CT was also performed and did not reveal an intraorbital abscess. Magnetic resonance imaging (MRI) of the brain and orbits showed diffuse enhancement of the right orbital fat, optic nerve sheath, and extraocular muscles (Fig. 2A). There was bulging and excessive enhancement of the lateral dural wall of the cavernous sinuses, as well as inhomogeneous enhancement of the sinuses, suggestive of thrombosis (Fig. 2B). Coronal images at the midorbital level showed nonopacification of the right superior ophthalmic vein (SOV) and inferior ophthalmic vein (IOV) (Fig. 2C). Dif-fusion- weighted imaging (DWI) showed increased signal (restricted diffusion) within the right IOV (Fig. 2D, G) and SOV, suggestive of thrombosis (Fig. 2E, F, H, I). These imaging findings were considered sufficiently conclusive for cavernous sinus thrombosis (CST) such that venography was not performed. Treatment with intravenous heparin was initiated. Blood cultures and material from the abscesses grew Streptococcus anginosus, a facultative oral anaerobe capable of producing systemic infections. Antibiotics were changed to ceftriaxone and metronidazole to treat infection by Streptococcus and other oral anaerobes. Within 48 hours, the facial and periocular swelling markedly subsided. Within 1 week, visual acuity and ocular motility had returned to normal. After 6 weeks, antibiotics and anticoagulation were discontinued. DISCUSSION Restricted diffusion within a thrombosed SOV in CST was first reported in this journal in a case of pansinusitis (1). A sub-sequent publication documented restricted diffusion in the SOVs bilaterally in a 64-year-old woman with a dental abscess (2). This is the first report of CST with MRI evidence of restricted diffusion, not only in a thrombosed SOV but also in a thrombosed IOV. By demonstrating restricted diffusion in the SOV and IOV, DWI confirmed thrombosis of these veins and the diagnosis of CST suggested by other neuroimaging features. These features include nonopacification and lateral wall bulging of both cavernous sinuses during the venous phase of the neck CT, excessive enhancement of the dural wall of the cavernous sinuses and inhomogenous contrast opacification of both sinuses and the right SOV and IOV on contrast-enhanced MRI. The high DWI signal in thrombosed vessels in the hyperacute stage likely results from multiple mechanisms including clot retraction, plasma resorption, osmotic changes in the extravascular environment, and changes in the hemoglobin molecule (3). As the thrombus ages and hemoglobin molecule changes, the signal becomes hypoin-tense. The exception is the late subacute phase, in which red cell lysis and inflammatory cell infiltration may cause the DWI signal to become high again (3,4). 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. 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. 4. Kang BK, Na DG, Ryoo JW, Byun HS, Roh HG, Pyeun YS. Diffusion-weighted MR imaging of intracerebral hemorrhage. Korean J Radiol. 2001;2:183-191. 270 De Lott et al: J Neuro-Ophthalmol 2013; 33: 268-270 Photo Essay Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. |
