Eye-Catching MRI Findings in Giant Cell Arteritis

Photo and Video Essay Section Editors: Kimberly M. Winges, MD Michael J. Gilhooley, MA, MB, BChir, DPhil Eye-Catching MRI Findings in Giant Cell Arteritis Sara F. de Carvalho, MD, MSc, Margarida M. Ribeiro, MD, MSc, Andreia G. Costa, MD, MSc, Carina C. Reis, MD, Daniela M. Ferro, MD, MSc FIG. 1. MRI of the orbits. (A) Bilateral optic nerve sheath enhancement, along with slight enhancement of the optic nerves (note left side optic nerve enhancement) on axial T1 VIBE after gadolinium, (B) subtle hyperintensity of the optic nerves on diffusion weighted imaging (DWI), and (C) inappreciable corresponding hypointensity on the aparent diffusion coefficient (ADC) map. A n 81-year-old Caucasian man was admitted to the hospital with headache, sudden vision loss in the left eye (oculus sinister, left eye), retro-orbital pain exacerbated with eye movement, and significant weight loss in the previous 3 months. Relevant medical history included polymyalgia rheumatica, hypertension, and dyslipidemia. The visual acuity (VA) was 7/10 in the right eye (oculus dexter, right eye) and 2/10 in the left eye. Slitlamp examination (SLE) revealed peripapillary atrophy but normal optic disc in the right eye and pallid disc edema in the left eye with retinal pallor in the cilioretinal artery distribution. Infrared examination showed hyporeflectivity in the area of the cilioretinal Departments of Neuroradiology (SdC, CR) and Neurology (AC, DF), Centro Hospitalar Universitário de São João, Porto, Portugal; Department of Clinical Neurosciences and Mental Health (AC, DF), Faculty of Medicine, University of Porto, Porto, Portugal; Department of Ophtalmology (MR), Centro Hospitalar Universitário de São João, Porto, Portugal; and Unit of Pharmacology and Therapeutics (MR), Department of Biomedicine, Faculty of Medicine of Porto University, Porto, Portugal. The authors report no conflicts of interest. Address correspondence to Sara de Carvalho, MD, MSc, Alameda Prof. Hernâni Monteiro, 4200–319 Porto, Portugal; E-mail: [e-mail] e178 artery. The erythrocyte sedimentation rate (ESR) was 47 mm/h (normal , 20 mm/h), C-reactive protein (CRP) was 44.6 mg/L (normal , 3 mg/L), and a superficial temporal artery (STA) echo-Doppler documented a bilateral halo sign (1). The patient was diagnosed with a cilioretinal artery occlusion, probably due to giant cell arteritis (GCA) and underwent a 5-day course of intravenous (IV) methylprednisolone 1 g/d followed by oral prednisolone 60 mg/ d and was discharged from the hospital with follow-up on consultation. An orbital MRI was performed, after hospital discharge and first steroid infusion, which revealed bilateral optic nerve (better appreciated on the left) and sheath enhancement (perineuritis) and a slight hyperintensity of the optic nerves on diffusion weighted imaging (DWI), particularly on the left side, but with inappreciable corresponding hypointensity on the apparent diffusion coefficient (ADC) map (Figs. 1, 2). Bilateral optic nerve enhancement may suggest inflammatory or demyelinating etiologies (for instance, neuromyelitis optica spectrum disorders or multiple sclerosis) while perineural sheath enhancement points to inflammatory diseases (such as granulomatous diseases), sheath neoplasm, or infiltrative optic perineuritis (2). de Carvalho et al: J Neuro-Ophthalmol 2024; 44: e178-e179 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited. Photo and Video Essay FIG. 2. MRI of the orbits. Coronal view of T1 VIBE after gadolinium. Despite adequate corticosteroid therapy, 3 weeks later, sudden vision loss in the right eye occurred, and the patient was readmitted to the hospital. Other symptoms included bitemporal headache, anorexia, and increased weight loss. VA was 4/10 in the right eye and light perception in the left eye. The right pupil was poorly reactive, and the left pupil was nonreactive. SLE revealed disc pallor in the right eye with pallid edema and important peripapillary atrophy and left eye disc pallor with poorly defined borders. STA echoDoppler was again performed and showed similar results to the previous one, with sustained bilateral temporal superficial artery halo sign. ESR was 7 mm/h, and CRP was 5.2 mg/L. The patient underwent a new course of high-dose corticosteroid therapy with IV methylprednisolone 1 g/d, followed by IV immunoglobulins 0.4 g/ kg/d for 5 days, with no signs of clinical improvement. Owing to the atypical presentation of a case of GCA with no response to implemented therapies and considering the existing abnormal orbital MRI features, the patient was submitted to an extensive diagnostic workup, including cerebral MRI, lumbar puncture, upper endoscopy, colonoscopy, cervico-thoraco-abdomino-pelvic CT scan, and a positron emission tomography (PET) scan, to investigate and exclude other inflammatory, demyelinating, infectious, and (para-)neoplastic causes, which were all unremarkable. Finally, STA biopsy confirmed GCA, showing an inflammatory infiltrate in intimal, muscular, and adven- de Carvalho et al: J Neuro-Ophthalmol 2024; 44: e178-e179 titia layers of the STA with rare multinucleate giant cells. The patient started subcutaneous tocilizumab 162 mg/weekly, with little clinical improvement. VA at hospital discharge remained unaltered compared with the previous examination at the time of the right eye vision loss. Although MRI is believed to be normal in patients with GCA, there are few recent descriptions of abnormal imaging findings (2). Optic nerve, perineural sheath, optic chiasmal, or nonspecific orbital enhancement may be found and mimic other etiologies. As in our patient, the cases reported in the literature of GCA with bilateral optic nerve or optic nerve sheath enhancement on MRI most frequently presented with unilateral or bilateral vision loss or diplopia as a major complaint. With this case, we emphasize that these MRI findings, in the presence of typical clinical symptoms and laboratory/ultrasonographic signs, should not delay diagnosis and treatment of such eye and life-threatening condition. STATEMENT OF AUTHORSHIP Conception and design: Sara de Carvalho, Andreia Costa, Carina Reis, Daniela Ferro; Acquisition of data: Sara de Carvalho, Carina Reis; Analysis and interpretation of data: Sara de Carvalho, Margarida Ribeiro, Andreia Costa, Carina Reis, Daniela Ferro; Drafting the manuscript: Sara de Carvalho, Margarida Ribeiro, Andreia Costa, Daniela Ferro; Revising the manuscript for intellectual content: Sara de Carvalho, Margarida Ribeiro, Andreia Costa, Carina Reis, Daniela Ferro; Final approval of the completed manuscript: Sara de Carvalho, Margarida Ribeiro, Andreia Costa, Carina Reis, Daniela Ferro. REFERENCES 1. Soares C, Costa A, Santos R, Abreu P, Castro P, Azevedo E. Clinical, laboratory and ultrasonographic interrelations in giant cell arteritis. J Stroke Cerebrovasc Dis. 2021;30:105601. 2. D’Souza NM, Morgan ML, Almarzouqi SJ, Lee AG. Magnetic resonance imaging findings in giant cell arteritis. Eye. 2016;30:758–762. e179 Copyright © North American Neuro-Ophthalmology Society. Unauthorized reproduction of this article is prohibited.