Spinal injuries are among the most common injuries resulting from an accident.  The spine is divided into three regions – cervical (neck), thoracic (mid-back), and lumbar (low back).  Depending on whether the spinal nerves have been affected, a person may experience tingling, numbness or pain in her arms/hands following a cervical spinal injury or numbness, tingling and pain in the legs with a low back injury. In this blog I will touch upon one particular type of low back spinal injury, “Cauda Equina Syndrome.” This is a devastating generally permanent condition involving full or partial loss of bowel and bladder function, sexual function, pain or numbness in the legs, and an impaired ability to walk. The condition is named after a series of nerves found in the lower part of the spinal canal called the Cauda Equina, Latin for “horse’s tail”, a description of the appearance of the nerves.

          The spinal cord descends from the brain down your back and ends in the lower back. Beneath approximately the first lumbar vertebrae, the cauda equina spinal nerve roots exist within the spinal canal without the protection of the spinal cord, terminating in the coccyx (tail bone).

What causes Cauda Equina Syndrome?

          Although there are many causes of cauda equina syndrome, all result from compression of the cauda equina nerve roots which increases pressure on the nerves and disrupts the blood supply to them. One of the most common causes of this compression is due to a central herniated disc. Herniated means movement of part of the disc structure – the nucleus – from its proper anatomical location; central means that the nucleus has moved into the spinal cord itself where the cauda equina nerve roots exist, as opposed to either side of the spinal canal where a single nerve exits.  If the herniated disc comes into contact with just a single nerve, a person might feel low back pain traveling or radiating down own one leg. But if the disc compresses the cauda equina – which is a series of nerves – the person might experience low back pain radiating down both legs plus bowel/bladder/sexual impairment, loss of sensation around the upper thighs and groin, and difficulty raising or lowering your feet (dorsiflexion or plantarflexion) which will affect your ability to walk.

Diagnosis and treatment

          Cauda Equina Syndrome is a clinical diagnosis, i.e. it is made once a person develops radiating low back pain, loss of bowel/bladder function and sensory loss and foot weakness. While not every central herniated disc results in Cauda Equina Syndrome, only a central herniated disc can cause the condition (again I remind readers I’m only referring to a herniated disc as a cause of compression.) The compression of the cauda equina nerves and onset of symptoms means the patient is in a medical emergency and must have immediate surgery.  Some medical literature states that there’s a 24 – 48 hour window in which symptoms can be relieved if the pressure on the cauda equina nerves is removed by surgery.  Beyond that time, the symptoms are likely to be permanent in nature.  

          Diagnosis of compression of the cauda equina nerves can only be made with imaging studies – MRI, CT or Myelogram. If these films show significant spinal canal stenosis (narrowing of the spinal canal wherein the cauda equina nerve roots lie) immediate referral should be made to a spinal surgeon. The patient’s clinical symptoms of low back pain with radiating pain together with the MRI findings showing significant stenosis, means that the person runs a risk of developing cauda equina syndrome. The safest course at this point would be surgery, before the onset of bowel/bladder etc. symptoms, as once these begin permanent deficits may not be avoidable. On the other hand, if surgery is performed before bowel/bladder etc. symptoms develop, there is no chance that a cauda equina syndrome will develop, because the root cause – central herniated disc compressing the cauda equina nerve roots – will have been eliminated. From the patient’s vantage point, low back pain running down one or both legs is a symptom which must be taken very seriously and evaluated by a spinal surgeon as soon as possible to avoid the possibility of a life altering condition.

          Athough cauda equina syndrome is a rare condition, I have had experience with several such cases. Among all medical-legal cases, cauda equina syndrome is among the most unfortunate, leaving a person’s life unalterably changed by permanent bowel, bladder, sexual and mobility deficits.  Should you, a loved one or friend have developed cauda equina syndrome and wonder whether the condition arose from medical negligence, I would welcome discussing your case with you.