What is the cauda equina?

CES is a serious type of nerve root problem where there is a pressure on the nerves at the very bottom of the spinal cord. The nerves at the base of the spinal cord are squeezed that causes pain in the lower back and/or legs, numbness or weakness in one or both legs, in the buttocks or between the legs

Cauda equina is called horse tail because the collection of nerves at the bottom of the spinal cord looks same like volumized horse tail.

Though Cauda equine syndrome is rare but is a severe neurological disorder that can lead to incontinence or even paraplegia if left untreated.

CES commonly results in low back pain, problems with bowel and bladder function (not able to pass urine), weakness in legs, numbness in saddle area.

Cauda Equina Syndrome needs urgent treatment and investigation to prevent the nerves of bladder and bowel from becoming permanently damaged.

What do the nerves do?

Nerves acts differently in the whole body, some join to form the sciatic nerves and some provide the sensation and control for the bladder, anal and genital regions.

The Cauda Equina is behind the lumbar discs, in the spinal canal. The lumbar discs sit between the vertebrae but they rupture sometimes which is known as slipped disc. And this happens suddenly usually in the younger people. This rupture makes the nerves of caudal equine trapped and squased.

Older people faces this problem due to arthritic changes within the spine.

Causes of Cauda Equina Syndrome

1. Trauma – Trauma can lead to fracture or dislocation of the lower back that can result in compression of caudal equina. Collection of blood in the nerves, gun shots or stab wounds, partial dislocation can damage or compression can cause cauda equina syndrome.
2. Herniated Disk– Seventy five percent cases of herniated disk leads to caudal equine syndrome in people with the history of chronic lower back pain and even some develop caudal equine syndrome as the first symptom of lumbar disk herniation. Males aged between30-40 are prone to caudal equine syndrome caused by disk herniated.
3. Spinal Stenosis:This term can be explained as the narrow distance of the front and back of the spinal canal. The abnormal narrowing of the spinal canal is due to the developmental abnormality or degenerative process and is called spondylolisthesis. The severe cases lead to caudal equine.
4. Tumors – CES syndrome can be caused by isolated tutors or the tutors that have spread to the spine from other parts of the body. The initial symptom cauda equina syndrome caused by atumour is severe low back and leg pain.
5. Infectious Conditions –Infections can cause deformity of the nerve roots and spinal column in the spinal canal.
6. Inflammatory Conditions –Spondylitis and the Paget’s disease can lead to narrowing of the spinal canal and lead to cauda equina syndrome.

Cauda Equina Syndrome Symptoms

1. Low back pain
2. Sciatica
3. Numbness in the groin or area of contact if sitting on a saddle
4. Bowel and bladder disturbances
5. Lower extremity muscle weakness and loss of sensations
6. Leg pain
7. Inability to urinate
8. Decreased sensation while urinating
9. Inability to stop or control urination
10. Constipation

Medical Care and Treatment

This syndrome is a surgical emergency. Patient should immediately seek medical emergency if the doctor believe the symptoms of caudal equine syndrome. The initial symptoms like low back pain and muscle weakness are often caused by disk herniation which doesn’t require urgent attention but if the symptoms increases to develop severe palm or loss of sensation, bowel or bladder disturbance then an immediate medical attention is required.

The initial diagnosis is based on the findings from patients history, symptoms and physical exam. The tests include muscle strength testing, evaluating sensation to touch and pain, sensation and reflex.

X-ray and MRI helps in diagnosis of evidence of trauma , severe arthritis , tumours, infection, intervertebral disks, and nerve roots. It is a most important study required to diagnose if the nerves are being compressed, to what degree, and by what structures.

These studies help doctor or the surgeon to plan the appropriate treatment. The medical treatment options are useful in certain cases and the underlying cause of the caudal equina syndrome.

In the inflammatory cases, anti-inflammatory agents and corticosteroids are effective. Cauda equina syndrome caused by an infection should receive appropriate antibiotic therapy. Patients with spinal tumors should be evaluated for chemotherapy and radiation therapy.

Patient having symptoms of groin numbness or weakness or loss of bowel or bladder control should not wait for more than 24 hours for medical help. If there is no relief after initial treatment, immediate surgical decompression is often recommended to minimize the chances of permanent nerve injury.

The emergency decompression of the spinal canal is the best treatment option for this syndrome. The motive is to relieve pressure on the nerves of the cauda equina by removing the compressing structures and increasing the space available for the nerves in the spinal canal.

CES is considered as a  surgical emergency, with surgical decompression considered necessary within 48 hours of the onset of symptoms.

People having herniated disk as a cause of cauda equina syndrome, are suggested to remove the portion of the bone surrounding the nerves.

About the author- Dr Arvind G Kulkarni, ‘Head of Mumbai Spine Scoliosis & Disc Replacement Centre, Bombay Hospital, Mumbai