Thickening and Contrast Enhancement of Spinal Roots on MR Imaging in Guillain-Barré Syndrome: Thoughts on Pathologic Background

A, Complete semithin transverse section of the L5 ventral root in a control subject with no pathology. B, Complete semithin transverse section of the L5 ventral root from the patient reported in reference 3. Note that despite apparent severe reduction of myelinated fibers, the transverse fascicular area is preserved or even increased (A and B, toluidine blue, original magnification, ×10 objective). C, At higher magnification, note extensive inflammatory demyelination with numerous denuded axons and foamy laden macrophages (toluidine blue, original magnification, ×63 oil immersion objective).