Cauda Equina Syndrome: Specialists and Information

Cauda equina syndrome (ICD code G83.4) involves damage to the nerve fibers at the lower end of the spinal cord.

The cauda equina is a cluster of nerve roots that run through a sac of tissue (dural sac) within the spinal column. This structure begins at the conus medullaris, roughly at the level of the first lumbar vertebra, and extends down to the sacrum in adults.

The nerve roots resemble a horse’s tail in shape, which is why they are called the cauda equina (Latin for “horse’s tail”). The dural sac, which protects the nerve structure, is filled with cerebrospinal fluid.

Normally, the nerve roots have sufficient space within this dural sac and can adjust their position as needed. In cauda equina syndrome, however, the dural sac becomes compressed. This increases the pressure inside the sac, causing the nerve roots to become constricted and, in the worst case, damaged.

Here you can see the location of the cauda equina in the lower spine © Henrie / Fotolia

The main cause of cauda equina syndrome is a herniated disc, often in conjunction with a narrow spinal canal (spinal stenosis). In this condition, parts of the intervertebral disc protrude into the spinal canal and press on the nerve fibers.

Tumors or metastases in the lumbar spine can also cause cauda equina syndrome. Anatomical abnormalities, such as those that occur in the embryonic closure disorder spina bifida, are also considered risk factors for cauda equina syndrome.

Due to nerve compression, various neurological deficits occur, such as

• severe back pain that may radiate into the lower legs, as well as
• sensory disturbances in the buttocks or thighs, such as tingling, sensations of cold or heat, and numbness. 

Because of their typical location, these sensory disturbances are also referred to as “riding-breeches anesthesia.”

Cauda equina syndrome is also characterized by

• absent reflexes in the patella and Achilles tendon regions, as well as
• motor abnormalities in the foot area.

For example, patients with cauda equina syndrome are often unable to lift their feet (weakness of the foot lifter).

Other signs of cauda equina syndrome may include:

• sudden-onset impotence,
• flaccid paralysis, as well as
• urinary or fecal incontinence.

If these symptoms occur, prompt action is required! This is especially true if the patient already has a history of back problems or disc disorders. 

If the diagnosis is clear, cauda equina syndrome is a neurosurgical emergency. Prompt treatment of cauda equina syndrome is urgently needed. The surgeon performs a procedure to decompress the nerves.

If this procedure is not performed within six hours of the onset of the first symptoms, there is a high risk of permanent nerve damage. 

The prognosis for cauda equina syndrome depends on

• the time elapsed from the onset of symptoms to surgery and
• the severity of the nerve compression

. The patient’s age, gender, and any underlying medical conditions also play a role in the course of the syndrome.

In cases of complete CES, the chances of a complete and rapid recovery of nerve function are rather low. Many patients continue to experience neurological deficits and still suffer from incontinence or paralysis even after surgery.

Weakness of the sphincter muscles, particularly when accompanied by fecal and/or urinary incontinence, is considered a particularly poor prognostic sign.

Even though the prospects for a complete recovery are relatively low, cauda equina syndrome should be treated as soon as possible. As soon as the first signs of nerve compression appear, it is therefore recommended to call an emergency physician immediately.