Figure 1.

Three patients diagnosed with primary‐progressive multiple sclerosis had focal white matter changes. (A) Axial FLAIR images with a punctate lesion in the right deep white matter (white arrow); (B) axial FLAIR images with only a few small, focal white matter lesions located in the deep white matter of both the left and right brain hemispheres (white arrows); and (C) axial FLAIR images with small, focal lesions located in the right brain hemisphere's deep white matter (white arrow) and periventricular white matter, Figure from Siger. ⁴²