• Ahn NU, Ahn UM, Nallamshetty L, Springer BD, Buchowski JM, Funches L, Garrett ES, Kostuik JP, Kebaish KM and Sponseller PD (2001). Cauda equina syndrome in ankylosing spondylitis (the CES-AS syndrome): meta-analysis of outcomes after medical and surgical treatments. J Spinal Disord. 14 (5): 427-33. Summary: The cauda equina syndrome in ankylosing spondylitis (the CES-AS syndrome) is marked by slow, insidious progression and a high incidence of dural ectasia in the lumbosacral spine. A high index of suspicion for this problem must be maintained when evaluating the patient with ankylosing spondylitis with a history of incontinence and neurologic deficit on examination. There has been disagreement in the literature as to whether surgical treatment is warranted for this condition. A meta-analysis was thus performed comparing outcomes with treatment regimens. Our results suggest that leaving these patients untreated or treating with steroids alone is inappropriate. Nonsteroidal antiinflammatory drugs may improve back pain but do not improve neurologic deficit. Surgical treatment of the dural ectasia, either by lumboperitoneal shunting or laminectomy, may improve neurologic dysfunction or halt the progression of neurologic deficit. Department of Orthopaedic Surgery, Johns Hopkins University, Baltimore, Maryland, USA.