Cauda equina syndrome due to lumbar disc herniation and ossification of the yellow ligament.

Background Patients with lumbar disc herniation at a level with significant stenosis due to ossification of the yellow ligament (OYL) may rarely present with rapid neurological deterioration warranting emergent surgery. Case description A 40-year-old female developed an acute cauda equina syndrome (CES) attributed to an acute lumbar disc herniation and to marked canal stenosis due to OYL. As the patient underwent a 9 h delayed removal of the ossified ligament and discectomy, she sustained only minimal recovery. Conclusion Patients diagnosed with acute lumbar disc herniation and severe stenosis due to OYL who present with acute CES warrant emergent surgical decompression to avoid permanent postoperative neurological sequelae.