Cauda Equina Syndrome

• Acute onset is marked by a rapid development of symptoms that often includes severe low back pain and significant loss of bladder and bowel function. In an acute onset, sensory and motor deficits in the lower body typically develop within 24 hours.

Symptoms of cauda equina syndrome can develop suddenly, but may take weeks or months. The onset of the condition is often described using the following distinctions:

• Acute onset is marked by a rapid development of symptoms that often includes severe low back pain and significant loss of bladder and bowel function. In an acute onset, sensory and motor deficits in the lower body typically develop within 24 hours.
• Gradual onset can develop over progressively, and symptoms may come and go over the course of several weeks or months. Gradual onset usually typically includes partial or intermittent loss of bowel and bladder function, as well as recurring low back pain in combination with muscle weakness and numbness and bladder and/or bowel incontinence or dysfunction. Sciatica may also occur in one or both legs.

Loss of bowel or bladder function may include incontinence (inability to retain urine or stool), and/or constipation (inability to eliminate urine or stool).

It is possible for a patient to develop cauda equina syndrome with no history of back pain, or in a patient with a long or recent history of low back pain or sciatica

The Cauda Equina and Its Function

The cauda equina gets its name from Latin for “horse’s tail,” because the nerves at the end of the spine visually resemble a horse’s tail as they extend from the spinal cord, through the lumbar spine and over the sacrum, and down the back of each legs.

The cauda equina consists of about 10 pairs of nerve roots, some of which combine to form larger nerves in the lower body—one example of which is the sciatic nerve.

The cauda equina is responsible for sensory and motor innervation to the pelvis and lower limbs, as well as bowel and bladder function. If the cauda equina is damaged by inflammation or compression in the low back, symptoms may be severe and may develop quickly. Early medical attention and treatment are crucial for making as full a recovery as possible.[/toggle_block]

The severity of cauda equina syndrome symptoms varies depending on the degree of nerve compression. For some patients, cauda equina syndrome (CES) develops suddenly while other patients experience a gradual onset of symptoms.

Typical symptoms of cauda equina syndrome include:

• Neurological symptoms in the lower body. Weakness, tingling, or numbness in the legs, and/or feet on one or both sides of the body is a common symptom. Lower body weakness or numbness may make it difficult to walk or stand.
• Altered sensation in the “saddle region,” or saddle anesthesia. The saddle region is the area of the body that would be in contact with a saddle when sitting on a horse. This region includes the groin, the buttocks and genitals, and the upper inner thighs. With cauda equina syndrome, all or parts of this region may have neurological symptoms of numbness, tingling, and/or weakness.
• Bladder or bowel incontinence. Recent onset of bowel or bladder dysfunction, including incontinence and retention, is one of the primary red-flag symptoms of cauda equina syndrome. Bladder/bowel dysfunction typically consists of a poor urinary stream, an altered or lack of sensation while urinating, urinary retention, loss of rectal control, and/or the need to strain in order to urinate.
• Sharp or stabbing pain in the legs or lower extremities. Compression of the cauda equina may lead to sciatic nerve pain felt on both sides of the body, and may be experienced as a sharp, hot pain felt down the backs of the thighs and possibly into the lower legs and feet.
• Localized lower back pain. A dull, steady ache may be felt across the lower back and/or pelvis, potentially causing discomfort or stiffness.
• Patients who experience any combination of the above symptoms should seek immediate medical treatment, as the condition can progress suddenly and requires prompt medical treatment.

Cauda equina syndrome typically requires prompt surgical decompression in order to reduce or eliminate pressure on the impacted nerves. Most surgeons recommend decompression as soon as possible, within about 8 hours of the onset of symptoms if symptoms develop suddenly.

While there are conflicting reports in the literature regarding the timing of treatment, it is generally thought that surgery within 24 to 48 hours gives the maximum potential for improvement of sensory and motor deficits. In one meta-analysis, patients who underwent surgery within 48 hours of onset were found to have a significant improvement in sensory/motor deficits and bowel and bladder function over patients who received treatment after 48 hours.¹ However, even patients who undergo surgery later may experience improvement in their urinary and rectal function, and neurologic deficits.

Surgical Decompression

Cauda equina syndrome is best treated with decompression by a lumbar laminectomy, but a lumbar microdiscectomy may be used given a patient’s unique situation.

Watch: Lumbar Microdiscectomy Surgery Video

The patient will likely be kept in the hospital for a few days following the surgery to monitor recovery of motor and sensory function.

Post-Surgical Prognosis

The prognosis for cauda equina syndrome depends on a variety of factors, such as how promptly the nerve is decompressed and the degree of nerve damage at the time of surgery.

Following surgery, the extent of recovery is variable. Patients may continue to experience some low back or leg pain, bladder or bowel dysfunction, and other physical problems depending on the duration of nerve compression and the severity of symptoms at the time of surgery.

While it is generally thought that neurological damage caused by cauda equina syndrome is permanent, some studies have reported that long-term management may allow patients with initially poor prognosis following surgery to eventually regain a near-normal voiding of a bladder with little daily interruption