Abnormal spinal meningeal morphology Dural ectasia 2011-06-07T05:22:13Z UMLS:C1851712 HP:0100775 A widening or ballooning of the dural sac surrounding the spinal cord usually at the lumbosacral level. Dural ectasia is one of the major manifestations of Marfan syndrome. It may cause low back pain, headaches and neurological signs such as weakness and loss of bowel and bladder function, but in many patients it is asymptomatic. It is also a cause of posterior vertebral scalloping present in radiographs in patients who are diagnosed with Neurofibromatosis. Dural ectasia may also manifest in Ehlers-Danlos Syndrome, cauda equina syndrome and in ankylosing spondylitis.