What is the cauda equina?
The spinal cord ends at the lower edge of the first lumbar vertebra where it tapers to form the conus medullaris. The lumbar and sacral nerve roots that arise from the lower part of spinal cord form a bundle within the spinal canal below the conus medullaris. This bundle of nerves is similar in appearance to a horse's tail and is called the cauda equina, from the latin (See Fig. 1 and Fig. 2). Lumbar and sacral nerve roots leave the spinal canal and send and receive nerve impulses to and from the lower limbs and pelvic organs.
What is Cauda Equina Syndrome?
Cauda Equina Syndrome (CES) occurs when the nerves within the spinal canal have been damaged. As a result, the nerves supplying the muscles of the legs, bladder, bowel and genitals do not function properly. Patients experience numbness, loss of sensation and pain in the legs, buttocks and pelvic region to varying degrees. The damage is usually permanent.
What are the causes of Cauda Equina Syndrome?
Whilst the cauda equina is protected by the vertebrae (backbone) it is still vulnerable to damage.
Causes of cauda equina damage can be separated into those that are present at birth (congenital), and those acquired after birth.
|Congenital causes of Cauda Equina Syndrome:
Acquired causes of Cauda Equina Syndrome:
- Spina bifida (abnormality in closure of spinal canal)
- Tumours of the cauda equina
- Injury (spinal fractures)
- Secondary to medical procedures
- Intravertebral disc herniation ("Slipped" or "prolapsed" disc)
- Tumours of the cauda equina
- Vascular (blood vessel) problems of the cauda equina
- Infections (eg CMV, cytomegalovirus) of the cauda equina
What happens to the cauda equina following damage or injury?
In mild cases, the myelin sheath that surrounds and protects the nerves is damaged, resulting in temporary dysfunction, which lasts for a few weeks or months. There are no long-term effects, and mild cauda equina injury may even be unrecognised by the patient or doctor.
In other cases the nerve fibres (axons) are damaged but the nerves to the muscles (motor nerves) can regrow over time. In certain cases, surgery can limit nerve damage and thus aid the natural repair process. Regrowth can take up to a year, but unfortunately some degree of dysfunction persists permanently. This is partly due to the fact that the nerve fibres transmitting sensation (sensory nerves) do not regrow efficiently. As a consequence, tingling and numbness usually persists despite good recovery of muscle power. When permanent damage to the motor nerves occurs, wasting of the muscles supplied by these nerves can be a problem, resulting in weakness (eg buttocks, sphincters and legs).
What are the symptoms of Cauda Equina Syndrome?
In this section of the website, we are focusing in particular on dysfunction of the pelvic organs (bowels, bladder and sexual organs) that typically follows cauda equina injury. Symptoms of pelvic organ dysfunction are often invisible to others, but can still severely affect the patient's quality of life. In addition, other problems such as difficulty in walking or severe unexplained pain can be a source of great distress. There is considerable variation in both the type and severity of symptoms amongst patients, which depends on the degree of injury to the nerves of the cauda equina. We have a lot of sympathy for how you are feeling because, as cauda equina patients, we too faced this devastating change in our lives and continue to live with CES.
Pelvic floor dysfunction in Cauda Equina Syndrome is divided into four areas of disability, namely: bowel problems, bladder problems, sexual problems, and other problems.
Page Last Updated: 10 June 2004