Fig. 1.

Brain MRI findings. Brain MRI on day 21 (left panel). Coronal (a, b) and axial (c, d) contrast-enhanced FLAIR images of a brain MRI. Hyperintensity of the pre-chiasmatic cisternal segment of the left optic nerve (arrows) consistent with optic neuritis, along with focal high-intensity content in right parietal peri-rolandic sulci (arrowheads), as a sign of focal leptomeningitis. Furthermore, a diffuse dural enhancement can be noted, consistent with a recent lumbar puncture. Follow-up brain MRI on day 35 (right panel). Coronal (a, b) and axial (c, d) contrast-enhanced FLAIR images of a brain MRI, all of them at the same level as the findings described in Fig. 2. Persistence of mild optic neuritis signs can be noted (a, b). We can also appreciate the resolution of the dural enhancement, and a normal LCR signal intensity content in peri Rolandic sulci, consistent with disappearance of focal leptomeningitis (c, d)