Clinical findings. (a) Skin rashes over the nasal sidewall and peripheral facial palsy on the right side 3 months before admission. (b) A visual field test on admission identified a central scotoma in the right eye and quadrantanopia in the left (L) eye. (c) The optic disc was atrophied and pale in the right (R) eye; there were no abnormal findings in the left eye. (d) Brain magnetic resonance imaging (MRI) on admission. Fluid-attenuated inversion recovery (FLAIR; left) imaging demonstrated multiple hyperintense periventricular deep white matter and juxtacortical lesions, some of which exhibited an open ring pattern on T1-weighted imaging after gadolinium (Gd) enhancement (right).