Cauda Equina Syndrome

Cauda equina syndrome was first described in 1934 by William Mixter and Joseph Barr. It was described in an English medical journal with the title ‘rupture of the intervertebral disc with the involvement of the spinal cord’.

Since then it has become a well-recognised neurological condition. Nevertheless, it remains a rare occurrence, with most GPs only seeing one case during the course of their professional career.

Causes of cauda equina syndrome

Cauda equina syndrome is when the cauda equina nerve roots, located below the conus medullaris at the end of the spinal cord, are compressed. Compression results in nerve damage and dysfunction.

The most common cause of compression is a herniated lumbar disc (also called a prolapsed disc or slipped disc). Around 3% of all herniated lumbar discs will lead to cauda equina syndrome.

There are different levels in the spine and a disc can herniate at any point. The majority of cauda equina syndrome cases occur due to a herniated disc at the L4-L5 level and the L5-S1 level.

Other causes of cauda equina syndrome include: spinal stenosis, spinal tumours, haematomas, infections, fractures and inflammation.

Symptoms of cauda equina syndrome

The symptoms of cauda equina are: low back pain, saddle numbness, sciatica, muscle weakness in the legs/feet, bladder dysfunction and bowel dysfunction.

These symptoms can appear very suddenly, as with acute cauda equina syndrome. Or these symptoms can appear very gradually, as with chronic cauda equina syndrome.

Diagnosing cauda equina syndrome

Not all patients will have every single symptom. The most important indicators of cauda equina syndrome are numbness around the genitals, perineum and buttocks, as well as urinary disturbance.

A patient with the symptoms of cauda equina syndrome should undergo a neurological assessment. This will verify if the clinical signs of cauda equina syndrome are present, including: loss of perineal sensation, lax anal tone, and motor weakness in the lower limbs.

A patient should also undergo an MRI scan. This will reveal whether the nerves are being compressed. It should also confirm what exactly is causing the compression.

Treating cauda equina syndrome

Cauda equina syndrome can only be treated with surgical decompression.

Much has been made of the timing of surgery. Indeed, cauda equina syndrome is a medical emergency. Like cancer, the prognosis for cauda equina syndrome is much improved the earlier surgery is performed.

However, there are just hours to treat the condition or a patient will be left with permanent dysfunction. One study states that patients are five times more likely to achieve normal bladder function if operated on within 24 hours of the onset of symptoms, as opposed to after 48 hours.