from: nerve root compression

Pathophysiology of nerve root compression

• <65 y: 90% from disc herniation. ≥65 y also w/ more degenerative contributors: ligamentous hypertrophy, osteophyte formation, facet arthropathy, neural foraminal narrowing

• Spinal stenosis: central canal narrowing → root compression via direct impingement, CSF flow obstruction, vascular compromise

Nb, lumbar disc protrusion tends to compress the nerve root that exits 1 vertebral level below the protrusion.