Your spinal cord is the thick bundle of nerves that runs from your brain down the inside of your spine. The spinal cord is like an electric cable that carries signals back and forth between your brain and body.
Signals from the brain tell your body what to do, such as moving your arms or legs
Signals to the brain carry information from your body such as what you're touching or where it hurts
The spinal cord is very delicate. It's protected inside a tunnel in your spinal bones (vertebrae). The tunnel is called the spinal canal.
Spinal nerves are medium-sized nerves that connect your spinal cord to smaller nerves that travel to different parts of your body.
How the Spine Is Organized
A column of bones called vertebrae make up the spine (spinal column). The vertebrae protect the spinal cord, a long, fragile structure contained in the spinal canal, which runs through the center of the spine. Between the vertebrae are disks composed of cartilage, which help cushion the spine and give it some flexibility.
Spinal nerves: Emerging from the spinal cord between the vertebrae are 31 pairs of spinal nerves. Each nerve emerges in two short branches (roots).
The motor roots carry commands from the brain and spinal cord to other parts of the body, particularly to skeletal muscles.
The sensory roots carry information to the brain from other parts of the body.
Cauda equina: The spinal cord ends about three fourths of the way down the spine, but a bundle of nerves extends beyond the cord. This bundle is called the cauda equina because it resembles a horse's tail. The cauda equina carries nerve impulses to and from the legs.
What is spinal cord compression?
Spinal cord compression is when your spinal cord is squeezed by something pressing on it:
The part that's compressed doesn't work right
If the compression continues long enough, it permanently damages your spinal cord
Only the nerve signals below the compressed area are affected
Symptoms may include back pain, numbness, muscle weakness, or trouble controlling your urine or bowel movements
Sometimes, symptoms affect only one side of your body
Doctors do an MRI Magnetic Resonance Imaging (MRI) MRI is a test that uses a machine with a powerful magnet to make pictures of the inside of your body. A computer creates a series of detailed pictures. Each picture looks like a slice taken... read more (magnetic resonance imaging) or other imaging tests
Corticosteroid medicine sometimes lessens swelling that comes from compression
You may also need surgery or radiation therapy to relieve the compression
What causes spinal cord compression?
The most common causes of spinal cord compression include:
Cancer that has spread to your spine
Narrowing of your spinal canal by excessive bone growth (spinal stenosis Lumbar Spinal Stenosis Lumbar spinal stenosis is narrowing of the spinal canal in the lower back. The narrowing squeezes (compresses) the nerves that travel through the lower back into the legs. Osteoarthritis, injuries... read more )
The discs in your spine are round, flat pads of soft material. They act like shock absorbers between each of your spine bones. Sometimes a disc splits open and the soft material inside bulges out (herniates). The material can compress your spinal cord or one of your spinal nerves.
Less common causes include:
Hematoma (a collection of blood from an injury or illness)
Abscess (a pocket of pus from an infection)
What are the symptoms of spinal cord compression?
The main symptoms include:
Pain in your spine
Muscle weakness or paralysis
Loss of sensation (can't feel pain or someone touching you)
Difficulty controlling your urine and bowel movements
The parts of your body that are affected depend on which part of your spinal cord is compressed. For example:
Compression of the spinal cord in your neck affects both your arms and legs
Compression high up in your neck may affect your ability to breathe
Compression further down may affect only your legs and your arms may be okay
Compression at any level can keep you from controlling your urine and bowel movements.
If your cord is compressed only on one side, then only one side of your body is affected.
The severity of your symptoms depend on the severity of the compression.
Mild spinal cord compression may cause only:
Slight muscle weakness
Severe compression may cause:
Severe muscle weakness or complete paralysis
Complete loss of sensation (can't feel pain or someone touching you)
Inability to control your urine and bowel movements
If you have cancer and have new back pain or nerve symptoms, that's considered a medical emergency. Doctors need to make sure your spinal cord isn't being compressed by the cancer.
How can doctors tell if I have spinal cord compression?
Doctors suspect spinal cord compression if you have weakness or loss of sensation only below a certain point on your body.
Doctors will then do testing, such as:
How do doctors treat spinal cord compression?
Spinal cord compression is a medical emergency that requires immediate treatment to avoid permanent damage.
Treatment depends on the cause and can include:
Draining of a hematoma or abscess
But even early treatment doesn't guarantee all your symptoms will go away.