Cauda equina syndrome

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Introduction0:00–0:22

Cauda equina syndrome is a condition caused by damage to the bundle of peripheral nerves protruding from the bottom of the spinal cord, called the cauda equina.
The latin words cauda equina mean horse’s tail, which is what early anatomists thought this nerve bundle looked like. The spinal column is made of individual bones, called vertebrae.

Anatomy and physiology0:22–2:30

Each vertebra is made of a large anterior portion called the body, and the posterior part called the vertebral arch. The central cavity between the body and the arch is called the vertebral foramen.
Now the spinal column is made of 33 vertebrae: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 4 coccygeal. Each cervical, thoracic, and lumbar vertebra is separated by an intervertebral disc, which allows for a slight movement of the vertebrae, and act as a shock absorber.
The sacral and coccygeal vertebrae are fused together to form the sacral bone and coccyx, or tailbone respectively. Now if you cut the spinal column in half lengthwise you can see that all the vertebral foramina together form the vertebral, or the spinal canal, which is occupied by the spinal cord.
The spinal cord is connected to the brain and travels through the spinal canal to the second lumbar vertebra, where it ends in a cone, called conus medullaris.
There are 31 pairs of nerves originating from the spinal cord called spinal nerves; there are 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal.
Each nerve leaves the spinal canal through the corresponding intervertebral foramen, which are openings between two adjacent vertebrae.
Since the spinal cord is shorter than the spinal canal, the nerves of the lumbar, sacral and coccygeal regions have to travel down the spinal canal to reach their corresponding openings, forming a nerve bundle below the spinal cord called the cauda equina.
These nerves carry motor innervation for the genitals, both internal and external anal sphincter, detrusor vesicae, which is a muscle in the bladder that contracts during urination, and muscles of the leg.
They are in charge of the knee and ankle reflexes. Skin sensations of the legs and pelvis are also carried by these nerves.

Pathology2:30–4:16

Cauda equina syndrome is caused by compression, trauma, or damage to multiple nerves of the cauda equina. Large lumbar disc herniation is the most common cause of cauda equina syndrome.
And poor posture, traumas, physical activity, and strong rotational movement can cause herniations where the intervertebral disc bulges out and compress the nerves or spinal cord.
This is similar to sciatica, but the herniation is usually larger, and more nerves are compressed, including those that control the bladder and reproductive organs.
Compression can also be caused by spinal stenosis which is the narrowing of the vertebral foramen in the lumbar vertebrae.
It can be congenital, meaning that the person is born with it, or acquired, usually due to degenerative disorders like ankylosing spondylitis, where the bones remodel causing intervertebral discs ossification, and the narrowing of the spinal canal.
Another cause is spondylolisthesis where a lumbar vertebrae is displaced. This can be caused by trauma, surgery or degenerative spinal disease.
The most common type of lumbar spondylolisthesis is anterolisthesis, where a vertebra moves forward and narrows the spinal canal, causing compression of the nerves.
Finally, any trauma to the spine, like the one caused by a car crash, gunshot, etc. can lead to nerve damage or compression directly, or by causing bleeding inside the spinal canal, causing compression via hematomas.
Finally any growths within the spinal canal like tumors, cysts, or abscesses can cause compression on the spinal cord and nerves.

Symptoms4:16–4:55

Symptoms of cauda equina include decreased bowel and bladder control due to a decreased tone of anal sphincters and muscle wall of the bladder and decreased sexual function.
It can also cause saddle anesthesia, which is a loss of sensation in the saddle area, which includes the buttocks, inner surface of the thigh and perineum.
One or both legs can be impaired by muscle weakness, loss of knee and ankle reflexes, and even paraplegia, which is when the affected person loses all feeling and muscle control in the legs.
Sometimes, there can be sciatic pain, which is a sharp pain going down the back and leg. Diagnosis of cauda equina syndrome is usually based on the pattern of sensory and motor nerve findings and confirmed by an MRI or CT scan.

Diagnosis4:55–4:55

Diagnosis4:55–5:06

Treatment5:06–5:36

The treatment of cauda equina syndrome depends on the cause. If it was caused by disc herniation, trauma, tumors or abscess, the symptoms appeared suddenly, and surgical decompression should be performed within 48 hours.
Abscesses should also be treated with antibiotics. However if it’s caused by degenerative disease, then symptoms appear more gradually, and it’s treated with anti-inflammatory medications and corticosteroids.
All right, as a quick recap cauda equina syndrome is a condition caused by damage or compression to the nerves or cauda equina.

Review5:36–6:04

The most common cause is lumbar disc herniation. Typical symptoms include decreased urinary and bowel control, decreased sexual function, and saddle anesthesia.
Depending on the cause cauda equina syndrome can be treated surgically, as well as by anti-inflammatory medications or by antibiotics.