Dural ectasia is widening or ballooning of the dural sac surrounding the spinal cord. This usually occurs in the lumbosacral region, as this is where the cerebrospinal fluid pressure is greatest, but the spinal canal can be affected in any plane.
Case courtesy of Dr Franco Ruales, Radiopaedia.org. From the case rID: 16114
Most common symptoms include low back pain, headaches, weakness, numbness above and below the involved limb, leg pain, and sometimes there can be rectal and genital pain. Bowel and bladder dysfunction, urinary retention or even incontinence may occur.
The symptoms are usually exacerbated by upright posture and often but not always relieved by lying down. However, in many patients it is asymptomatic.
It is common in Marfan syndrome, occurring in 63–92% of people with the syndrome. Dural ectasia may also occur in Ehlers-Danlos Syndrome, neurofibromatosis type I, ankylosing spondylitis, and trauma.
A “classic” picture of dural ectasia in the Marfan patient may consist of low back pain, headache, proximal leg pain, weakness and numbness above and below the knee, and genital/rectal pain. Symptoms, when present, are typically moderate to severe, occur several times per week (often daily), are commonly exacerbated by upright posture, and are not always relieved by recumbency 1).
Saccular dural diverticula (type I, n = 28) caused by defects of both dural layers, dissections between dural layers (type II, n = 29) due to defects of the inner layer, and dural ectasias (type III, n = 9) related to structural changes of the dura were distinguished. For all types, symptoms consisted of local pain followed by signs of radiculopathy or myelopathy, while one patient with dural ectasia presented a low-pressure syndrome and 10 patients with dural dissections additional spinal cord herniation. Type I and type II pathologies required occlusion of their dural defects via extradural (type I) or intradural (type II) approaches. For type III pathologies of the dural sac no surgery was recommended. Favorable results were obtained in all 14 patients with type I and 13 of 15 patients with type II pathologies undergoing surgery.
The majority of dural pathologies involving nerve root sleeves remain asymptomatic, while those of the dural sac commonly lead to pain and neurological symptoms. Saccular dural diverticula (type I) and dissections between dural layers (type II) pathologies were treated with good long-term results occluding their dural defects, while dural ectasias (type III) were managed conservatively 4).