Dural ectasia refers to ballooning or widening of the dural sac (the dura is the membrane that lines the brain and spinal cord). The dura becomes weakened and expands outwards.
It tends to affect people who have certain health conditions. For example, dural ectasia is present in more than 60 percent of people who have Marfan syndrome, because of weak connective tissue.
Other conditions which have a higher incidence of dural ectasia include:
- Ehlers-Danlos syndrome
- Loeys-Dietz syndrome
- Ankylosing spondylitis
- Osteogenesis imperfecta
- Vertebral fracture
- Postopertative adhesions
In many people, dural ectasia is asymptomatic, however it can cause a range of symptoms, including:
- Aching in the very low back, almost in the tailbone
- Abdominal pain
- Pain and numbness in the perineum
- Leg pain
- Numbness in the calves
Dural ectasia causes issues because as the membrane expands, it presses on the vertebrae in the lower back. However, occasionally, ectasia can also occur in the neck or in the upper torso. For the vast majority of of people with dural ectasia, it affects in the lowest part of the spine. This is because this is where the fluid pressure is greatest when standing.
MRI imaging can identify dural ectasia. A mylogram, CT scan, might also reveal its presence.
Greater than normal volume of cerebrospinal fluid can have implications for a person having surgery on the spine. Dural ectasia is an important factor to consider for spinal anaesthesia. It is one of the likely causes of incomplete or failed spinal anaesthesia.