The cauda equina is a bundle of nerve roots located at the base of the spinal cord. The descriptive Latin name is a reference to the physical appearance of the cauda equina; it looks like a horse's tail. A rare neurological condition known as cauda equina syndrome can cause damage to the nerve roots involved, leading to lower back pain, loss of sensation in the legs, and incontinence.
When vertebrates develop, their spinal cords actually stop developing before their spines do. As a result, although people think of the spinal cord as something which runs down the length of the whole spine, it actually stops short. The cauda equina, which marks the end of the spinal cord, is located between the first and third lumbar vertebrae. It splits off into sacral, lumbar, and coccygeal nerves which feed out through the vertebrae.
In lumbar punctures, where a sample of spinal fluid is taken for analysis, the doctor taking the sample aims for the cauda equina with the needle. In these procedures, care is taken to hit the right area of the spine and to avoid injuring or traumatizing the patient. Stress on the part of the patient can complicate the procedure and the results, and patients may be offered sedatives in advance so that they will be able to relax.
The nerves which originate at the cauda equina are responsible for sending and receiving signals from the lower limbs and the organs in the pelvis. As a result, damage to the cauda equina can cause significant problems for the patient. This can include paralysis of the lower limbs, limb weakness and lack of coordination, and abnormal sensations in the lower limbs which become disruptive over time.
This region of the spinal cord can be injured by herniated discs, trauma, and degenerative diseases, among many other things. Signs of injury can include difficulty moving or controlling the lower limbs, muscle pain and weakness, numbness and tingling, fecal or urinary incontinence, and pain which may be localized in the lower back or distributed down the legs. Diagnostic testing, such as magnetic resonance imaging (MRI), can be used to identify damage to the cauda equina and develop a treatment plan for the patient.
Treatment of disorders involving the cauda equina usually involves a neurologist and a neurosurgeon or spinal specialist. The neurologist can perform patient evaluations which will provide information about the area and extent of the damage, while the surgeons can conduct repairs, if necessary.