Cauda equina syndrome is a neurological condition affecting the spine and the nerve roots surrounding the spine. This very uncommon condition raises the need for emergency medical attention and treatment. Here is some background information: the spinal cord lengthens from the brain down through the spinal canal inside a structure called the vertebral column. There are various nerves that branch off the spinal cord (called nerve roots) that are basically an extension of the spinal cord, responsible for sending signals to and from the muscles and other structures in the body. This process allows the brain to interpret the information into something we can relate to: pain, touch, and sense of position. Outgoing signals allow the brain to control the movements of organs, muscles, and the like. There is a bundle of nerve roots at the base of the spinal cord called the cauda equina; when these nerve roots become compressed or inflamed, severe symptoms will undoubtedly occur. This is the phenomenon of cauda equina syndrome. It is a surgical emergency because if not treated promptly, it will result in permanent, irreversible damage.
The signs and symptoms associated with cauda equina syndrome are painful and are sometimes hard to diagnose because they can range in intensity, and sometimes even take quite some time to fully develop. They include: lower back pain (which can be local and due to soft tissue and vertebral body irritation, or stabbing leg pain resulting from compression of the nerve roots); pain in one or both legs that starts at the buttocks and travels down the back of the legs; numbness in the groin; bowel and bladder disturbances (such as urinary retention, difficulty initiating urination, decreased sensation when urinating, and incontinence for urinary, and constipation, inability to stop or feel a bowel movement, or loss of anal tone and sensation for bowel); lower extremity muscle weakness; loss of sensations in the lower extremities; and reduced or absent lower extremity reflexes.
The cause of cauda equina syndrome are of the narrowing of the spinal canal that ultimately compresses the nerve roots below the level of the spinal cord; there are numerous reason why this would happen, including traumatic injury, disk herniation, spinal stenosis, spinal tumors (neoplasms, such as metastatic tumors, meningiomas, schwannomas, and ependyomas), inflammatory conditions, infectious conditions, and accidental causes due to medical intervention (called iatrogenic).
The initial diagnosis is made based off the patient’s symptoms, medical history, and physical exam. The extent of the physical exam would be testing muscle strength of the lower extremities, evaluating sensation to touch and pain, checking the lower extremity reflexes, and evaluating rectal tone, sensation, and reflex. It is possible that the diagnosis may need imaging tests to be done, like x-ray of the lower back to assess degenerative changes; MRI with and without contrast to look at tumors, intervertebral disks, and nerve roots (this allows a closer examination and for the doctor to determine to what degree the nerves are compressed and by what structures).
As mentioned above, treatment should be started as soon as possible so permanent changes do not occur, such as paralysis and permanent loss of bladder control; it goes without saying that if you experience any of the symptoms, go to the emergency room. However, the treatment depends on the cause. If it caused by an inflammatory process, anti-inflammatory medications (such as ibuprofen) could be taken. If it is caused by an infection, antibiotics will be the first treatment. Lastly, surgery is needed in most causes to decompress the nerve roots (surgical decompression); this must be done within 48 hours from the onset. The goal of surgery is to remove the structures that are causing the compression, allowing more space for the nerves of the spinal canal. For example, if a herniated disk is the cause, removal of a portion of the bone surrounding the nerves and the disk material compressing the nerves is removed as well. If the surgery is done early, the chance of preventing permanent damage raises greatly. It is always important to have follow-up appointments after surgery so the physician can monitor the progress.
The outcome, or prognosis, of an individual with cauda equina syndrome depends on how long the symptoms were present prior to treatment. The longer the individual has the symptoms, the less likely that he or she will fully recover.