Cauda Equina Syndrome
Low back pain affects millions of people every year, and in most
cases, it improves without surgery. But severe back pain can be a
symptom of a serious condition that is not well known and is often
misdiagnosed. Cauda equina syndrome (CES) occurs when the nerve roots of
the cauda equina are compressed and disrupt motor and sensory function
to the lower extremities and bladder. Patients with this syndrome are
often admitted to the hospital as a medical emergency. CES can lead to
incontinence and even permanent paralysis.
The collection of nerves at the end of the spinal cord is known
as the cauda equina, due to its resemblance to a horse's tail. The
spinal cord ends at the upper portion of the lumbar (lower back) spine.
The individual nerve roots at the end of the spinal cord that provide
motor and sensory function to the legs and the bladder continue along in
the spinal canal. The cauda equina is the continuation of these nerve
roots in the lumbar region. These nerves send and receive messages to
and from the lower limbs and pelvic organs.
CES is not related to gender or race. It occurs primarily in
adults, although trauma-related CES can affect people of all ages. CES
affects a very small percentage of patients that have undergone surgery
for lumbar herniated disc.
CES most commonly results from a massive herniated disc in the
lumbar region. A single excessive strain or injury may cause a herniated
disc. However, disc material degenerates naturally as you age, and the
ligaments that hold it in place begin to weaken. As this degeneration
progresses, a relatively minor strain or twisting movement can cause a
disc to rupture.
The following are other potential causes of CES:
lesions and tumors
- Spinal infections or inflammation
- Violent Injuries to the lower back (gunshots,
falls, auto accidents)
- Birth abnormalities
arteriovenous malformations (AVMs)
- Spinal hemorrhages
(subarachnoid, subdural, epidural)
- Postoperative lumbar spine
- Spinal anesthesia
Symptoms and Diagnosis
CES symptoms mimic those of other conditions. Its symptoms may
vary in intensity and evolve slowly over time. CES is accompanied by a
range of symptoms, the severity of which depend on the degree of
compression and the precise nerve roots that are being compressed.
Besides a herniated disc, other conditions with similar symptoms to CES
include peripheral nerve disorder, conus medullaris syndrome, spinal
cord compression, and irritation or compression of the nerves after they
exit the spinal column and travel through the pelvis, a condition known
as lumbosacral plexopathy.
Patients with back pain should be aware of the following "red
flag" symptoms that may indicate CES:
- Severe low back pain
- Motor weakness, sensory loss, or pain in one, or more commonly
- Saddle anesthesia (unable to feel anything in the body areas
that sit on a saddle)
- Recent onset of bladder dysfunction (such as urinary retention
- Recent onset of bowel incontinence
- Sensory abnormalities in the bladder or rectum
- Recent onset of sexual dysfunction
- A loss of reflexes in the extremities
Medical history implications:
- Recent violent injury to the back
- Recent lumbar spine surgery
- A history of cancer
- Recent severe infection
The following tests may be helpful in diagnosing CES:
Magnetic resonance imaging (MRI): A diagnostic test that
produces three-dimensional images of body structures using magnetic
fields and computer technology. MRI produces images of the spinal cord,
nerve roots, and surrounding areas.
Myleogram: An x-ray of the spinal canal following
injection of a contrast material into the surrounding cerebrospinal
fluid spaces; can show displacement on the spinal cord or spinal nerves
due to herniated discs, bone spurs, tumors, etc.
Once the diagnosis of CES is made, and the etiology established,
urgent surgery is usually the treatment of choice. The goal is to
reverse the symptoms of neural dysfunction. Left untreated, CES can
result in permanent paralysis and incontinence.
Those experiencing any of the red flag symptoms should consult a
neurosurgeon as soon as possible. Prompt surgery is the best treatment
for patients with CES. Treating patients within 48 hours after the onset
of the syndrome provides a significant advantage in improving sensory
and motor deficits as well as urinary and rectal function. But even
patients who undergo surgery after the 48-hour ideal timeframe may
experience considerable improvement.
Although short-term recovery of bladder function may lag behind
reversal of lower extremity motor deficits, the function may continue to
improve years after surgery. Following surgery, drug therapy coupled
with intermittent self-catheterization can help lead to slow, but steady
recovery of bladder and bowel function.
Coping with CES
CES can affect people both physically and emotionally, in
particular if it is chronic. People with CES may no longer be able to
work, either because of severe pain, socially unacceptable incontinence
problems, motor weakness and sensory loss, or a combination of these
Loss of bladder and bowel control can be extremely distressing
and have a highly negative impact on social life, work and
relationships. Patients with CES may develop frequent urinary
infections. Sexual dysfunction can be devastating to the patient and
his/her partner and may lead to relationship difficulties and
Severe nerve-type (neurogenic) pain may require prescription pain
medication with side effects that may cause further problems. If the
pain is chronic, it may become "centralized" and radiate to other areas
of the body. Neurogenic pain tends to be worse at night and may
interfere with sleep. This type of pain tends to produce a burning
feeling that can become constant and unbearable. Sensory loss may range
from pins and needles to complete numbness, and may affect the bladder,
bowel and genital areas. Weakness is usually in the legs and may
contribute to problems walking.
It is essential that people with CES receive emotional support
from a network of friends and family members, if possible. It is
important to work closely with your physician on medication and pain
management. There are several medications prescribed to address pain,
bladder and bowel problems. In addition, some patients find that
physical therapy and psychological counseling help them cope with CES.