Cauda Equina Syndrome

Severe Compression of the Spinal Nerves

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Cauda equina syndrome is an unusual condition caused by severe compression of the spinal nerves in the lowest region of the spinal canal (lumbar spine). Most cases of nerve compression are not emergencies, but patients with cauda equina syndrome require urgent diagnosis for proper treatment.

The word caudo equina literally means "horse's tail," and is used because of the appearance of this segment of the spinal cord and spinal nerves.

  The lowest segment of the spine looks like a horse tail with the nerves branching off the base of the spinal cord.

Signs of Cauda Equina

Cauda equine syndrome causes symptoms due to the compression of the spinal nerves. The symptoms may vary in different patients in the type and the intensity. Patients with any symptoms of cauda equina should seek medical attention to determine if there is an emergency situation:

  • Difficultly controlling the bowel and/or bladder
  • Numbness around the genitals
  • Progressive numbness or weakness of the legs

Causes of Cauda Equina Syndrome

Anything condition that causes pressure on this region of the spinal nerves can cause cauda equina syndrome. These include problems such as:

The most common cause of cauda equina is a space-occupying condition, such as a tumor or large herniated disc, that abruptly takes up the space where the nerves were able to occupy previously.

  The abnormal nerve function that occurs is due to compression on the nerves, as well as compression of the blood supply to those nerves.

It is important to note that this condition can occur both as the result of an acute onset problem that develops very suddenly, or a gradual process that can occur over the span of weeks or months.

  Either way, this requires prompt diagnosis and treatment to prevent lasting problems as a result of the nerve compression.

Treatment of Nerve Compression

Cauda equina syndrome can become permanent if the symptoms are not properly addressed. Patients who have cauda equina may require emergency surgical treatment in order to relieve pressure on the affected nerves.  This surgery, called a spinal decompression, removes bone and soft-tissue from the back of the spine to allow more room for the nerves.  Depending on how much bone needs to be removed, there may need to be additional surgery to place spinal instrumentation to support the spinal column.

In general surgery should be performed as soon as possible after cauda equina is identified.  When surgery is performed within the first 24-48 hours after the onset of symptoms the results tend to be better.  Long-term prognosis depends on the extent of the nerve damage, and how quickly the pressure on the nerves was relieved. 


Spector LR, et al. "Cauda equina syndrome" J Am Acad Orthop Surg. 2008 Aug;16(8):471-9.

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