Definition of Cauda Equina Syndrome

How Is Cauda Equina Syndrome Defined?

Cauda equina syndrome is a rare and serious back-related condition. It needs immediate evaluation and treatment. No delay.

In Weisel et al (see cauda equina references) it is defined as a complex of symptoms.

The Signs and Symptoms

• Low back pain, often very severe. This is not regular back pain.
• Sciatica in one or both legs, again usually severe.
• Leg muscle weakness.
• Anal and genital loss of feeling or numbness, referred to as saddle anaesthesia.
• Sudden onset of bladder and/or bowel disturbance, such as retention (unable to pass urine) or incontinence. Sexual function may also be disturbed.

What Can Cause Cauda Equina Syndrome?

CES occurs when the nerves which are running down in the spinal canal are interfered with and their conduction is altered. It can be caused by fractures, tumours, infections, spinal stenosis and disc herniation. The commonest cause is trauma, eg accidents such as falls or road traffic accidents.

How Does CES Develop?

Acute CES may develop quickly eg within a week and may be sudden with no warning. People may fall into three main groups:

• Group 1 - there may be no previous history of back pain
• Group 2 - have a previous history of low back pain and sciatica
• Group 3 - have had back pain and sciatica for a few days, followed by bladder symptoms

Description of Group 1

Severe pain around the rectum/anus. Sciatic (leg) symptoms may be less severe (or even absent), urinary retention and severe back pain very common, sciatic pain and sensory changes affecting the buttocks, posterior thighs and calves and soles of feet.

Description of Group 2

As group 1 plus similar less severe episodes in the past not including urinary retention.

Description of Group 3

Initially have low back pain and sciatica, then gradually develop urinary retention.