Cauda Equina Syndrome

Low back pain is a symptom of cauda equina syndrome.

• Cauda equina syndrome is a complication from the compression of the nerves at the end of the spinal cord within the spinal canal.
• Cauda equina syndrome can be caused by any condition that results in direct irritation or pinching of the nerves at the end of the spinal cord.
• Partial cauda equina syndrome is the terminology that applies when there is incomplete compression of the nerves of the lower spinal cord.
• Symptoms of cauda equina syndrome include low back pain, numbness and/or tingling in the buttocks and lower extremities (sciatica), weakness in the legs, and incontinence of the bladder and/or bowels.
• Cauda equina syndrome is diagnosed based on characteristic symptoms and confirmed by neurologic and radiology testing.
• Cauda equina syndrome is a medical emergency generally requiring a surgical decompression operation.
• The outlook for patients affected by cauda equina syndrome is determined by the extent of damage to involved nerve tissue.

Cauda equina syndrome is an uncommon compression of the nerves at the end of the spinal cord within the spinal canal. The terminology cauda equina literally means the tail of the horse and refers to the normal anatomy of the end of the spinal cord in the low back where it divides into many bundles of nerve tracts resembling a horse's tail.

Compression of the spinal cord at this level can lead to a number of typical symptoms of the syndrome (low back pain, sciatica, saddle sensory changes, bladder and bowel incontinence, and lower extremity motor and sensory loss).

Cauda equina syndrome can be caused by any condition that results in direct irritation or pinching of the nerves at the end of the spinal cord. Causes of cauda equina syndrome include

• herniation of lumbar intervertebral discs,
• abnormal growths (tumor or cancer) adjacent to the lower spinal cord,
• localized infection near the spinal cord (epidural abscess), and
• localized bleeding (epidural hematoma) causing pressure on the spinal cord in the low back.

Localized lumbar tumors that can lead to cauda equine syndrome include

• ependymomas,
• metastatic cancer, and
• Paget's disease of bone.

Localized infection near the spinal cord can be caused by

• staphylococcus bacteria,
• tuberculosis bacteria (Mycobacterium tuberculosis from Pott's disease), and
• others.

Symptoms and signs of cauda equina syndrome include

• low back pain,
• numbness and/or tingling in the buttocks and lower extremities (sciatica),
• weakness in the legs, and
• incontinence of bladder and/or bowels.

The numbness of cauda equina syndrome typically is in the distribution of where the body would touch a saddle when sitting upon a horse, and is referred to as "saddle anesthesia."

Partial cauda equina syndrome is the terminology that applies when there is incomplete compression of the nerves of the lower spinal cord. This can elicit various degrees and combinations of the symptoms listed above. With complete cauda equina syndrome, the array of symptoms listed above is commonplace.

Cauda equina syndrome is clinically diagnosed based on the characteristic symptoms described above. Often, the physical examination can reveal hyperactive reflexes of the lower extremities. Because the syndrome is a medical emergency, neurosurgery or spinal surgery consultants should be notified immediately. Cauda equina syndrome can be confirmed with neurologic and radiology testing but such testing should not be delayed.

Specialized neurologic nerve testing of the lower extremities, such as nerve conduction velocity (NCV) and electromyography (EMG) tests can indicate nerve irritation effects in the low back. Radiologic testing such as CT (computerized axial tomography) and MRI (magnetic resonance imaging) scanning can document compressed spinal cord tissue.

Cauda equina syndrome is a medical emergency. Compression of the spinal nerves of the spinal cord can lead to permanent dysfunction of the lower extremities, bladder, and bowels. Once the precise cause of cauda equina syndrome is determined (see above), generally aggressive operative intervention with surgical decompression is initiated.

If the infection is present, antibiotics are given, usually intravenously. If a tumor is responsible for compression, after surgical decompression, radiotherapy or chemotherapy may be needed.

The long-term management of cauda equina syndrome depends on whether or not there are persisting symptoms after surgical decompression of the irritated nerve tissue. This can require pain medicine, physical therapy, supportive braces, urinary catheters, and other treatments until optimal nerve and muscle recovery occurs.

Cauda equina syndrome occurs as a result of conditions that are not predictable and is therefore not a preventable syndrome. However, cauda equina syndrome caused by infections initiated by IV drug abuse can be prevented by not using illegal IV drugs.

Ultimately, the outlook for patients affected by cauda equina syndrome is determined by the extent of damage to involved nerve tissue. In general, the longer the duration of the compression of the spinal cord, the longer the recovery period and the less likely complete recovery can occur.