Cauda equina syndrome (CES) occurs when the nerve roots in the lumbar spine become compressed, cutting off feeling and movement.

CES is a rare condition, affecting an estimated 1 in 33,000–100,000 people. The cauda equina — a group of nerves and nerve roots at the lower end of the spinal cord — helps control the legs, bladder, and other parts of the lower body.

CES is a surgical emergency. Without treatment, it can lead to long-term complications.

This article looks at CES in more detail, including the types, causes, and symptoms.

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The cauda equina is a collection of nerves at the end of the spinal cord. The name comes from its resemblance to a horse’s tail.

The spinal cord ends at the upper portion of the lumbar spine, or lower back.

The nerves of the cauda equina are responsible for providing motor and sensory function to the legs and the bladder. They do this by sending messages to the lower limbs and pelvic organs and receiving them back.

CES occurs when the nerves become compressed or otherwise compromised.

CES can cause a variety of symptoms. The type and severity of the symptoms depend on the location and extent of the compression.

Urinary retention — when the bladder fills with urine, but the person does not feel the need to urinate — is the most common symptom.

Other common symptoms include:

  • sexual dysfunction
  • urinary or bowel incontinence
  • saddle anesthesia, which is a sensory disturbance that may involve the genitals, anus, and buttock region
  • paralysis or weakness of more than one nerve root that extends into the legs
  • pain in the legs or back, called sciatica

There are two main types of CES: complete and incomplete.

Complete cauda equina syndrome

Complete CES occurs when the person loses control over their bladder and experiences retention of urine with overflow.

It results in incontinence and leaked urine.

Incomplete cauda equina syndrome

Incomplete CES occurs when a person still has control and feeling over their bladder, but may:

  • have a reduced desire to urinate
  • experience an altered sensation of bladder fullness
  • need to strain when urinating
  • have difficulty emptying the bladder

The most common cause of CES is a large herniated disk in the lower back. Although the herniated disk may be the result of a traumatic injury, some have no known cause.

Other potential causes of CES include:

CES may be difficult to diagnose, but early treatment can help prevent complications and permanent damage.

As a result, a person should speak with a doctor as soon as possible if they experience:

  • bladder issues
  • bowel issues
  • severe or progressive issues with the lower extremities, such as loss of sensation

A doctor will typically diagnose CES by conducting a physical examination, reviewing the person’s medical history, and ordering several imaging tests.

The physical examination will help the doctor assess a person’s:

  • stability
  • alignment
  • sensation
  • reflexes
  • strength
  • motion

Imaging tests may include X-rays, MRI scans, and CT scans to examine the spine.

Typically, once a doctor determines the cause and diagnosis of CES, they will perform emergency surgery.

The goal of this surgery is to remove the pressure from the nerve roots as quickly as possible.

Receiving treatment within 48 hours of the first symptoms provides the best chance of recovery, with a lower risk of sensory, motor, urinary, and bowel dysfunction.

Although most studies recommend the 48-hour time frame, a recent 2022 review stated that receiving surgery within 24 hours results in the best outcomes.

Either way, the sooner a person receives treatment, the better their outcome.

It may not always be possible to prevent CES from developing.

However, a person can take steps to reduce their risk of traumatic injury to the spine or spinal cord, which is a potential cause.

Steps to prevent traumatic injury can include:

  • wearing a safety belt at all times in automobiles
  • avoiding contact sports
  • wearing safety equipment and harnesses on job sites
  • wearing helmets and protective gear while riding bicycles and motorcycles
  • practicing safety measures when using firearms

A person’s outlook will be significantly better if they get emergency treatment within 48 hours of the onset of CES.

Without emergency treatment, a person has a high risk of developing permanent loss of function and paralysis.

A person with CES should see a slow recovery of bladder function over time, which could potentially take years. However, they should see improvements in their motor skills shortly after the surgery.

CES can significantly affect a person’s life, even with successful surgical intervention. It can take an emotional and physical toll that can lead to issues with social, work, and personal relationships.

A person may find that in addition to potential physical therapies, they benefit from psychotherapy, also known as “talk” therapy.

This may help them cope with potential depression and emotional issues related to changes in bowel and urine function or physical movement.

Other suggestions for a person to cope with CES include:

  • getting family members involved in their care process
  • working with medical advisors
  • joining a support group
  • trying physical therapy
  • working with social workers for help with missed work or paying bills
  • working with a sex therapist, in cases of sexual dysfunction

Managing bladder and bowel function

Bladder and bowel function may take years to return to normal.

A person may find that drug therapy combined with intermittent catheterization helps lead to recovery.

Another option is to work with a continence advisor. They can provide treatment and strategies to help improve continence and bowel function.

Below, we provide answers to frequently asked questions about CES.

What are the first signs of cauda equina?

The most common symptom of CES is urinary retention. A person may lose control of their bladder and experience leakage.

Other symptoms may include:

  • reduced sensation in the anal, genital, and buttock region
  • weakness or paralysis in the lower body
  • bladder or bowel incontinence

A person should seek emergency medical attention if they experience one or more of these symptoms.

Can you walk with cauda equina syndrome?

Whether or not a person can walk depends on the severity of CES.

In some cases, CES can cause severe pain in the lower back and legs. If this occurs, a person may experience difficulty walking.

CES can also cause weakness or paralysis in the lower extremities, which may make it difficult or impossible to walk.

How rare is cauda equina syndrome?

CES is a rare condition that affects about 1 in 33,000–100,000 people.

CES is a rare condition in which the nerve roots in the lower back become compressed.

The compression leads to various symptoms, including urine retention and pain.

The condition typically requires emergency surgery to correct. Following this procedure, the full recovery of normal functioning may take some time.