Cauda Equina Syndrome is a syndrome involving a group of signs and symptoms that are caused by compression of the cauda equina. Cauda equina literally means “horse’s tail,” named for its appearance. The spinal cord has many nerve roots and rootlets that branch off of it. In the upper spine these nerve roots branch off at specific levels and exit the spinal canal between the vertebrae. The lower lumbar nerve roots and the sacral nerve roots travel down past the end of the spinal cord before they exit. In the lower spinal canal this looks like a bundle of nerves that resembles a horse’s tail, hence ‘cauda equina’.
Cauda equina syndrome occurs when the cauda equina is compressed, and this compression causes dysfunction of the lower lumbar and sacral nerve roots. Compression can be caused by a large herniated disc, spinal tumor, trauma with a free bone fragment, a spinal hematoma or abscess, or can be a complication after spinal surgery.
Symptoms can include “saddle anesthesia,” or groin numbness in a distribution as if sitting on a saddle. Motor weakness, or trouble walking, can occur. This can lead to paraplegia, or paralysis, if left untreated. Other symptoms include low back pain, sciatica, sexual dysfunction, urinary retention, or urinary or fecal incontinence. These are all things controlled by the lower lumbar and sacral nerve roots. These can occur suddenly or gradually.
Treatment is usually surgical with a laminectomy with or without microdiscectomy. The procedure relieves the compression on the nerves of the cauda equine.
Lindsey Parker PA-C; Justin F. Fraser M.D.