Cauda Equina Syndrome - Causes, Symptoms and Treatment

Cauda Equina syndrome is a rare but serious lower back condition caused by compression of the very lowest part of the spinal cord.

What is the Cauda Equina and where is it?

cauda equina syndrome
The cauda equina starts about the 1st Lumbar level
and it looks a bit like a horses tail

The spinal cord actually ends quite high up in the back – at about the level of the 1st lumbar vertebra. At this point the spinal cord separates off into strands which bundle together to form the cauda equina (Latin for horses tail - and it does look a little like that). This important part of the spinal cord carries nerve impulses to and from important structures like your bladder and bowel.


What is Cauda Equina Syndrome?

Cauda equina syndrome is caused by a compression of this part of the spinal cord.

If this area of you spinal cord becomes squashed to the point that it becomes damaged then you may suffer permanent changes that may make you unable to control your bladder and bowel normally. It may also lead to loss of power and severe weakness in the legs - sometimes affecting your ability to walk.

The reason it is called a 'syndrome' is because it may cause a variety of problems which are different for each person. It entirely depends on which part of the cord is compressed and how badly it is squashed.

What causes a compression of the cauda equina?

1. A central disc bulge or prolapse

if the disc bulges backwards and to the middle (instead of the usual backwards and to the side) it can compress the spinal cord.

severe lower back problems
Sometimes a severe spinal disc prolapse or
bulge can cause a compression of the cauda equina.

2.A slip of one vertebrae on another (called a spondylolisthesis) can compress the cauda equina.

image of spondylolisthesis showing a slip of one vertebrae on another
Spondylolisthesis can cause compression
as the vertebrae slips forwards

3. Tumours and Cancer

Rare but serious, cancer can cause a compression of the cord.

What are the Symptoms of Cauda Equina Syndrome

Some of the symptoms of this serious problem to look out for are:

  • Changes in bladder or bowel function – in particular not being able to control your bladder or bowel, or trying to pass water and not being able to.

  • Numbness between the thighs in the saddle area of both legs

  • A feeling of loss of control in the legs that may sometimes interfere with your walking - your legs may feel as if they don't belong to you.

These symptoms are called red flags and will alert your doctor to a possible problem.

Diagnosis and Treatment

Diagnosis is made by your doctor taking a history and by the presence of any of the symptoms listed above.

  • This problem is a surgical emergency and you need an urgent surgical opinion if you have any signs or symptoms.

  • In the UK this means an immediate trip to A+E to get checked out.

  • There is no home or self treatment for this condition.

  • The risks of leaving the condition untreated are severe, they include permanent loss of bladder and bowel control and possible leg paralysis.

If you are in any doubt go to the emergency room or make an urgent appointment with your doctor straight away.

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Case Study

Cauda Equina is rare but serious. In my career I have spotted a few of these. This is a typical story (but not based on any one individual for privacy).

I assessed a lady and asked all the usual clearing 'red flag' questions about bladder and bowel dysfunction, loss of power or numbness in the saddle area. She answered no to these questions.

I asked her if she was sleeping and she said no she wasnt as her pain was keeping her awake.

Then she said something that bothered me. She said that she was having to take a nap most afternoons because she was so tired and she often woke up and had to rush to the toilet to empty her bladder. Sometimes she didn't quite make it in time.

I asked if this had ever happened before and she said she had only ever had occasional stress incontinence in the past after having her children. This was only now and then with coughing and sneezing. She put this new bladder symptom down to tiredness and medication.

I contacted her GP immediately and expressed my worry that this was a cauda equina, the GP arranged for emergency neurosurgical opinion. She was admitted and scanned the same day, the scan showed a large central disc bulge with compression of the cauda equina. She had successful decompression surgery the next day.

She came to see me a few weeks later and was fine, most of her symptoms had gone, her bladder was back to normal.


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Slide show on bulging and herniated discs

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References and Resources

If you want to read some more case stories this support group has an excellent page with case studies of people who have had this problem.

Greenhalgh, S & Selfe, J, 2009. A qualitative investigation of Red Flags for serious spinal pathology. Physiotherapy, 95(3), pp.224–227.

Greenhalgh, Sue, Selfe, James & Gifford, L., 2006. Red Flags: A Guide to Identifying Serious Pathology of the Spine 1st ed., Churchill Livingstone.