A neuroimaging case of chronic arachnoiditis.

A 50-year-old man complained of an eight-year-history of low back pain, ataxia, paresthesias, and dysesthesias from the waist down, bilateral leg weakness, and neurogenic bladder. In 2006, he underwent two lumbar laminectomies, initially for Tarlov’s cyst and lumbar pain with repeat surgery for failed back syndrome, complicated by meningitis. Lumbar MRI using T2-weighted images showed: (1) sagittal view with clustering of lumbar nerve roots descending on the spinal canal giving the false impression of descended conus medullaris and tethered cord (Fig. 1a); (2) axial view at L3 level with peripheral adhesion of nerve