In July 2020, a 63-year-old man developed fatigue, shortness of breath, dry cough and fever to 38 C. A chest radiograph revealed bilateral bronchopneumonia, more prominent on the left. Nasopharyngeal swab for the real-time polymerase chain reaction (RT-PCR) test for SARS-CoV-2 was negative. However, serology was positive for IgM and IgG antibodies against the virus. His erythrocyte sedimentation rate (ESR) was 75 mm/h, C-reactive protein (CRP) was 103.5mg/l, D dimer was 1281.05 ng/mL, lactate dehydrogenase (LDH) was 505 U/L, and ferritin 1004 ng/mL. His complete blood count was within normal limits (5.3x109 leucocytes, with slight predomination of granulocytes (84%)). Other biochemical analyses were unremarkable, except for an elevated glucose level (8 mmol/l). His oxygen saturation (SpO2) was 92%. Due to high clinical suspicion of COVID 19, he was hospitalized and treated with antibiotics and anticoagulant therapy. His history was positive for arterial hypertension, treated appropriately. Metformin was introduced in his therapy, with additional diabetes mellitus type II diagnosis. Ten days after presentation, he was discharged from the hospital with SpO2 96%, improved chest x-ray findings and improved clinical status. His laboratory values returned to normal over the subsequent two weeks. Seven days later, a nasopharyngeal swab was again negative. Viral serology remained positive for IgM and IgG, and he had lymphopenia (9%).
Four weeks later, he developed blurred vision in his right eye. Initially, visual acuity was normal, but within a week it decreased to 20/630 (0.03) on the right and remained normal (1.0) on the left eye. He had a small papillary edema on the right fundus. The other ophthalmological findings were orderly. At that time he complained of a headache, predominantly on the right side. He was directed to our clinic for suspicion of anterior arteritic ischemic optic neuropathy (AAION).
He was hyperopic (+3.5D OD and +2.0D OS), with additional presbyopia correction. He reported that 20 years prior, he suffered from headaches on the left side, resembling cluster headaches. His personal and family histories were unremarkable. On admission to our hospital, PCR for SARS-CoV-2 was repeated and it was negative. IgM and IgG antibodies remained positive.
Examination of his right fundus was notable for partial swelling of the optic nerve head and ganglion cell layer (Figure 1A). There was a relative afferent pupillary defect (RAPD). Other ocular fundus findings were normal bilaterally. His right eye was almost perimetrically blind, with visual field index (VFI) 1% and mean deviation (MD) -31.56dB; the pattern deviation (PSD) was not shown for a severely depressed field, and left eye had also a sensitivity reduction: VFI of 90%, MD -7.23 and PSD 1.86 dB.
Serology tests were negative for Borrelia burgdorferi, human immunodeficiency virus, herpes simplex, varicella zoster, cytomegalovirus, Epstein-Barr virus and hepatitis B and C viruses. QuantiFERON gold test for tuberculosis was negative. Angiotensin-converting enzyme levels were within normal values. Antinuclear antibody (ANA), antineutrophil cytoplasmic antibodies (ANCA) and rheumatoid factor (RF) tests were within normal range, as were antiphospholipid and anticardiolipin antibodies. An aquaporin 4 (AQP4) antibody test was negative. The following were also normal: ESR, CRP, fibrinogen, D-dimer, coagulation times, ferritin and homocysteine. Plain chest and head radiographs revealed no abnormalities. The only suspicious result which arrived in the meantime was reactive result for Venereal Disease Research Laboratory (VDRL) test. We consulted an infectologist, and agreed with him to do Western blot for T. pallidum
He was treated only with pulse methylprednisolone therapy of 1000 mg for five days in the clinic, with gastroprotection and glucose and blood pressure monitoring. On the fifth day of therapy his visual acuity was significantly better (20/63 or 0.3), and visual field showed significant improvement (Figure 2A). The headache stopped during the first days of therapy.
Brain magnetic resonance imaging (MRI) was performed on the seventh day of hospitalization, in three planes with multiaxial reconstruction, before and after the application of paramagnetic contrast. It revealed only microangiopathic and cortical reductive signs, a neuroglial cyst of 5 mm on the right temporal side, and normal appearing orbits and optic nerves. Spinal medulla on cervicothoracal contrast MRI was without significant alterations, with signs of spondyloarthrosis and hyperostosis.
After hospitalization, he was treated with prednisone tapering therapy for two weeks. On follow-up, three weeks later, he brought a Western blot tests for T. pallidum, which we ordered because of previous VDRL test result. The Western blot was negative for all antigenic bands for IgG and IgM. We consulted a neurologist who did not identified any neurological disorders. His right visual acuity was 20/25 (0.8), and disk edema was resolved entirely. The left eye had normal functions. We ordered MOG antibodies, and two weeks later, we received positive result (titer 1:40, indirect immunofluorescence, cut off 1:10).
At his final 3-month follow up, his visual acuity and computed visual field on the right eye were normal (VOD 20/20 or 1.0; Figure 2B). The visual evoked potentials (3C PVEP) showed slightly prolonged latency of the p100 wave, and OCT suggested slight thinning of optic nerve fibers and ganglion cells, after optic neuritis (Figure 1B). The MOG antibodies titer was 1:20 and SARS-CoV-2 titers for IgM and IgG were 17.32 and 40.02, respectively.