Fig 3.

Patient 3: A and B, Color FA cross-sectional images show elongation of the SCP (green).The white star indicates the fourth ventricle. Descending long tracts (corticospinal and corticopontine) appear in blue. The ventral and middle transverse pontine fibers are missing; the SCP decussation is not visible. B, The ectopic bundle of fibers appears in red at the dorsal aspect of the pons and seems not to connect the MCPs visible laterally. C, Coronal FA image shows the elongated SCPs running laterally (arrows); the dorsal band (arrowheads) crossing the midline may join either the SCPs vertically or the MCPs horizontally. D and E, 3D projections of tractography. In the control (D), ventral transverse fibers are clearly seen (black arrow) and the MCPs are of normal size (arrowheads). In patient 3 (E), long descending tracts and the MCPs appear smaller (arrowheads). The ectopic dorsal pontine fibers are visible (long arrow) and are not seen to definitely connect the MCP (arrowheads).