Cauda equina syndrome is commonly caused by a slipped disc (otherwise known as a herniated or prolapsed disc). In this article we explore slipped discs in more detail.
The anatomy of the spine
The spine is made up of circular bones called vertebrae. In between each vertebra is a disc. These allow the spine to be flexible and cushion the vertebra, preventing them from rubbing against each other. A disc has a tough, fibrous outer shell and a soft, jelly-like centre called the nucleus pulposus.
The spinal cord, which runs from the brain to the bottom of the back, is encased by the vertebrae. The hollow space through which the spinal cord runs is called the spinal column. The nerves from the spinal cord emerge from between the vertebrae to send and receive messages across the body.
What is a prolapsed disc?
When someone suffers a slipped disc, it does not mean that the entire disc has slipped out of place. Rather, it means that the outer part of the disc tears and the inner part bulges outwards. The bulging inner part of the disc may then press upon nearby structures such as nerves. The area may also become inflamed.
Most commonly a prolapsed disc will occur in the lower part of the back – known as the lumbar. The size of the prolapse will differ from person to person. Generally the larger the prolapse the worse the symptoms will be. Slipped discs are more likely to affect those between the ages of 30 and 50 years old, and are twice as likely to affect men.
What causes a slipped disc?
Most slipped discs occur when the disc is suddenly put under excess pressure. This might include, for example, heavy lifting. There are also factors that are known to increase the risk of a slipped disc, such as weight bearing sports, smoking, obesity, old age, and jobs that involve lots of lifting, sitting or driving. However, medical practitioners are not entirely sure why some people will suffer a slipped disc and others not.
Symptoms of a slipped disc
A slipped disc will cause back pain which is often severe and comes on very suddenly. This pain may be alleviated when lying down, and may increase upon coughing or sneezing. A prolapsed disc can also cause sciatic pain that radiates down one or both legs to the calf or foot. This occurs because a nerve root is being compressed or irritated by the surrounding inflammation. A compressed or irritated nerve root can also lead to pins and needles, and numbness and weakness in the buttocks and legs.
Symptoms of a prolapsed disc can improve with time, although a minority will require surgical intervention. If a disc is pressing upon the cauda equina nerves, urgent surgery is needed. If doctors fail to achieve this, there may be a case of medical negligence.