Presentation
2 days ago sudden onset low back pain while bending down, L leg pain and numbness/pins and needles from buttock to heel, no weakness. saddle anesthesia, PR normal tone. no incontinence from bladder or bowels. ?cauda equina/disc prolapse NOTE had cauda equina decompressed two years ago
Patient Data
L4/5: Discectomy with loss of disc height. No protrusion or bulge into the spinal canal. No exit foraminal stenosis.
L5/S1: Large left paracentral disc extrusion, with caudal migration. At this level, the disc compresses the transiting left S1 nerve. The migrated portion also compresses the transiting S2 nerve root lower down, with compression of the thecal sac and contents. Patent exit foramina.
Degenerative changes at L4/5 and L5/S1 levels, otherwise normal marrow signal. Normal distal cord and conus. Normal CSF signal. No concerning extraspinal findings.
Case Discussion
L5/S1 left paracentral disc extrusion and migrated component causing compression of the left S1 and S2 nerve roots. Note the patient had a previous discectomy at the level above.