Fig 1. Venous congestion of the spinal cord and separated tracts (patient 1, DTI25d). This 57-year-old woman presented with a 2-year history of progressive paresthesia in the bilateral lower limbs, followed by further development of leg weakness and sphincter problems. The McCormick score was II. A pial arteriovenous fistula that was fed by the lateral spinal artery arising from the left posteroinferior cerebellar artery was found.
A, T2-weighted images showed enlargement of the spinal cord at the C6 level with hyperintensity reflecting local venous congestion (arrow).
B, There was a dilated vessel at the anterior surface of the cord, which corresponded with a vein draining the shunt caudally, as depicted on selective injection during angiography.
C, Posterior view of the FT25d showed separated fascicles at the level of C6 (arrow), with global enlargement of the beam of tracts. The remaining fibers were grouped together into fascicles. By counting the tracts at the level of the congestion (674) and below it (741; ratio: lesion level/caudal to lesion = 0.91), we were able to show that there was no evidence of focal interruption of the tracts.