PMC5327755_01
Clinical course. After the treatment with intravenous methylprednisolone, cell counts and proteins of CSF decreased, and seizures disappeared. MTX: methotrexate, ETN: etanercept, PSL: prednisolone, CBZ: carbamazepine, VPA: sodium valproate, LEV: levetiracetam, ZNS: zonisamide, and mPSL: methylprednisolone.
CRINM2017-7638539.001.jpg
PMC5327755_01_CRINM2017-7638539.001.jpg
fig1
There was no notable family history.  Figure 1 shows clinical course (Figure 1).
Brain MRI findings on the 4th admission. (a) Axial T2 fluid-attenuated inversion recovery (FLAIR) image (1.5 T; TR 10000 ms, TE 108 ms). (b) Diffusion-weighted image (DWI) (1.5 T; TR 5000 ms, TE 75 ms). (c) T1-weighted image (T1WI) enhanced by gadolinium (1.5 T; TR 7.50 ms, TE 2.82 ms). MRI shows extensive thick linear hyperintensity of the leptomeninges in bilateral frontal lobe and the left parietal lobe on T2 FLAIR and DWI (red arrows). T1WI after gadolinium administration shows enhancement of the leptomeninges (red arrowhead).
CRINM2017-7638539.002.jpg
PMC5327755_01_CRINM2017-7638539.002.jpg
fig2
Although the cortex of the left parietal lobe had mild swelling, there were no abnormal findings in the white matter (Figure 2).
Brain biopsy. Microscopic view of biopsied specimen showed leptomeningitis with plasma cells and lymphocytes infiltration. Haematoxylin and eosin stain, magnification of (a) 100x and (b) 400x.
CRINM2017-7638539.003.jpg
PMC5327755_01_CRINM2017-7638539.003.jpg
fig3
A brain biopsy from the lesion in the right frontal lobe showed invasion of lymphocytes and plasma cells into the superficial brain layers, resulting in necrosis of the brain surface (Figure 3).
Brain MRI finding 2 years after treatment. T2 FLAIR image (1.5 T; TR 10000 ms, TE 108 ms). MRI performed 2 years after treatment no longer shows linear hyperintensity of the leptomeninges.
CRINM2017-7638539.004.jpg
PMC5327755_01_CRINM2017-7638539.004.jpg
fig4
On brain MRI, abnormal signals in the sulci improved (Figure 4), and the slow waves were rarely observed on EEG.