The Intervertebral Foramen and the Role it Plays in Spinal Stenosis

Spinal column showing vertebral bodies, discs, processes and intervertebral foramen.
Spinal column showing vertebral bodies, discs, processes and intervertebral foramen. Creative RM/Science Picture Co/Getty Images

Intervertebral Foramen

The intervertebral foramen is a key location of the spinal column because it gives passage to nerves that exit the spinal cord.  The word "foramen" is plural; "foramin" is the singular form.

The intervertebral foramen is an opening made by two adjacent, stacked vertebrae. In the spinal column, stacking occurs down the front part of the bones (called the bodies).

Behind the body of a vertebra is a ring of bone.

Looking at a vertebra from either side, the body and ring combination make an arch-like shape. A hole is created by the meeting of the "pillars" of the arch with the bone below. This hole is the intervertebral foramen.

Once the spinal nerve roots branch off the spinal cord (a key structure of the central nervous system that runs down the center of the spinal column, in another hole called the spinal canal,) they exit the column via intervertebral foramen. The nerves keep branching out to all parts of the body.

Neuroforaminal Spinal Stenosis

One common problem that affects the neuroforamen is spinal stenosis. Stenosis is a general medical term that refers to narrowing. Spinal stenosis is (generally, but not always) an age related disorder related to arthritis.

Spinal stenosis can occur in two places: The spinal canal and the neuroforamin. When spinal stenosis occurs in the spinal canal, it's called central canal stenosis.

When spinal stenosis occurs in the neuroforamina, it is called neuroforaminal stenosis.

With pain due to neuroforaminal spinal stenosis, arthritis-related bone growth (also known as bone spurs or osteophytes) that are present in the foramen sort of "bump into" the nerve root that passes through space.

As they do, they may cause pain or other symptoms down one leg or arm (called radicular pain if you experience pain only, or radiculopathy if the pain is accompanied by other sensations as well.) 

The main symptom of neuroforaminal stenosis is neurogenic claudication — a kind of cramping that is related to your posture. Most of the time, people with spinal stenosis feel better when they flex (bend forward at) the trunk, and worse when they arch their backs. Other symptoms include weakness and/or difficulty walking more than short distances.

Treatment for stenosis is usually aimed at relieving pain and preventing nerve symptoms from occurring or getting worse. You don't automatically need surgery if you have spinal stenosis, but if your symptoms correlated with findings on your X-rays, your doctor may suggest it — especially if you also experience one or more of the following:

  • Radiculopathy (pain, pins and needles, electrical sensations and/or weakness going down one arm or leg,)
  • Neurogenic claudication in your low back (discussed above,)
  • Myelopathy in your neck and/or upper or mid back (myelopathy symptoms are spinal cord related and occur in central canal stenosis.)  
  • Incapacitating pain.

The rest of the time, conservative (i.e. non-invasive treatment is used.) This may consist of medication and physical therapy.

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