[Cauda equina syndrome with plantar perforating ulcer and neurogenic osteoarthropathies in a case of rheumatismal pelvospondylitis].

The authors report a case of ankylosing spondylitis complicated by a cauda equina syndrome presenting with a plantar perforating ulcer and lesions of neuropathic arthropathy of the foot. On the basis of an analysis of 54 cases published in the literature they review the principal aspects of this complication of ankylosing spondylitis. Neurological manifestations occur late after several decades of progression of the disease. Urinary sphincter problems are common whilst trophic disturbances remain rare. Myelography and, above all, lumbar CAT scan reveal characteristic and stereotyped anatomical lesions: widening of the dural sac in its posterior part with meningoceles eroding the posterior vertebral arch. The pathogenic mechanisms are unknown. The authors suggest that lesions may start with posterior epidural inflammation rather than a primary process of arachnoiditis as has been mentioned in earlier publications.