case_images: PMC8631873_01
case_images: Brain magnetic resonance imaging (MRI) of patient 1 performed during acute attack. Axial T2-weighted (A-J) and FLAIR (K-T) images show multiple patchy hyperintense lesions in the tegmentum of the pons (A, K), bilateral midbrain (B-D, L-N), and right hippocampus (C, M); ovoid lesions with well-defined borders in the bilateral head of the caudate nucleus and putamen (E-G, O-Q); and spotty lesions involving bilateral paraventricular white matters (H, R) and subcortical white matters of the frontal lobes (H-J, R-T).
case_images: fimmu-12-772763-g001.jpg
case_images: PMC8631873_01_fimmu-12-772763-g001.jpg
case_images: f1
case_images: Repeat brain MRI scan revealed multifocal T1 hypointensities and T2 and fluid-attenuated inversion recovery (FLAIR) hyperintensities scattered in the brainstem (midbrain and the tegmentum of pons), basal ganglia (head of caudate nucleus and putamen), right hippocampus, and paraventricular and subcortical white matters of bilateral frontal lobes ( Figure 1 ). Some of these lesions showed hyperintensities on both DWI and apparent diffusion coefficient (ADC) maps and heterogeneous patchy or ring-like enhancement on gadolinium (Gd)-enhanced MRI ( Supplemental Figure 1 ).
case_images: Timeline of patient 1 with relevant data of the episodes and interventions. *This admission. mRS, modified Rankin scale; IVIg, intravenous immunoglobulin; IVMP, intravenous methylprednisolone.
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case_images: PMC8631873_02_fimmu-12-772763-g002.jpg
case_images: f2
case_images: ADC map ( Supplemental Figure 2 ). All lesions did not show any enhancement on Gd-enhanced MRI.
case_images: PMC8631873_02
case_images: Timeline of patient 1 with relevant data of the episodes and interventions. *This admission. mRS, modified Rankin scale; IVIg, intravenous immunoglobulin; IVMP, intravenous methylprednisolone.
case_images: fimmu-12-772763-g002.jpg
case_images: PMC8631873_02_fimmu-12-772763-g002.jpg
case_images: f2
case_images: ADC map ( Supplemental Figure 2 ). All lesions did not show any enhancement on Gd-enhanced MRI.
case_images: Brain magnetic resonance imaging (MRI) of patient 2 performed during acute attack. Axial T2-weighted (A-J) images obtained 4 days after onset show multiple patchy hyperintense lesions in the left brainstem (medulla, brachium pontis, and midbrain) (A-G) and juxtacortical white matters of the right frontal lobe (I). Axial FLAIR (K-T) images obtained 15 days after onset reveal expanding lesions in the brainstem (K-Q). Meanwhile, new patchy or spotty lesions are confirmed in the left occipital lobe (O, P) as well as juxtacortical and subcortical white matters of the left frontal lobes (R, T).
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case_images: PMC8631873_02_fimmu-12-772763-g003.jpg
case_images: f3
case_images: T1 hypointensities and T2 and FLAIR hyperintensities in the left brainstem (medulla, brachium pontis, and midbrain) and juxtacortical and subcortical white matters of bilateral frontal lobes and the left occipital lobe ( Figure 3 ). The majority of these lesions revealed hyperintensities on DWI and isointensities relative to normal white matter on
case_images: Timeline of patient 2 with relevant data of the past episodes and interventions. *This admission. mRS, modified Rankin scale; IVIg, intravenous immunoglobulin; IVMP, intravenous methylprednisolone; RTX, rituximab.
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case_images: PMC8631873_02_fimmu-12-772763-g004.jpg
case_images: f4
case_images: The timeline of patient 2 with relevant data of the episodes and interventions is presented in  Figure 4 .