While the term “stenosis” comes from Greek and means “choking,” spinal stenosis, however, has little in common with choking. So what is spinal stenosis?

There are two types of spinal stenosis: lumbar stenosis and cervical stenosis. While lumbar spinal stenosis is more common, cervical spinal stenosis is often more dangerous because it involves compression of the spinal cord, as explained below in more detail.

Lumbar Spinal Stenosis vs. Cervical Spinal Stenosis

  • In lumbar stenosis, the spinal nerve roots in the lower back are compressed, or choked, and this can produce symptoms of sciatica — tingling, weakness or numbness that radiates from the low back and into the buttocks and legs – especially with activity.

Lumbar Spinal Stenosis Video

  • Spinal stenosis pain in the neck (cervical spinal stenosis) can be far more dangerous by compressing the spinal cord. Spinal cord stenosis may lead to serious symptoms, including major body weakness or even paralysis. Such severe spinal stenosis symptoms are virtually impossible in the lumbar spine, however, as the spinal cord is not present in the lumbar spine.

In rare cases, lumbar stenosis can go no further than to produce severe persistent disabling pain and even weakness in the legs. Most cases of stenosis in the lumbar spine, however, have pain that radiates into the leg(s) with walking, and that pain will be relieved with sitting. This is called neurogenic claudication, which must be distinguished from circulatory claudication (due to arterial stenosis or constriction of blood vessels) to the legs, as discussed later in this article.

Spinal stenosis is related to degeneration in the spine and usually will become significant in the 5th decade of life and extend throughout every subsequent age group. Most patients first visit their doctor with symptoms of spinal stenosis at about age 60 or so. Patients need only seek treatment for lumbar spinal stenosis if they no longer wish to live with significant activity limitations, such as leg pain and/or difficulty with walking.

Spinal stenosis can occur in a variety of ways in the spine. Approximately 75% of cases of spinal stenosis occur in the lumbar spine (low back), which is called lumbar spinal stenosis, and most will affect the sciatic nerve which runs along the back of the leg. When this happens, it is commonly called sciatica.

Learning about spinal stenosis requires an understanding of  spinal anatomy. The vertebral column in the spine and sacrum (at the bottom of the spine) are like a stack of blocks that serve to support the structures of the body.

Each of these bony structures has additional bony attachments that serve to help stabilize the spine and to protect the spinal cord or nerves passing downward from the brain to organs, muscles, and sensory structures of the body. Each vertebral body and its attachments and the disc between the adjacent vertebrae are known as a spinal segment.

The entire length of the spinal column has a large central canal or passage through which the spinal cord descends, and holes to each side of the canal to allow emergence of spinal nerves at each level. The spinal cord stops at the upper part of the low back, and below that the tiny, contained nerve rootlets descend loosely splayed out – like a horse’s tail – and are protectively enclosed in a long sack. All central nerve structures are protected further by membranes, with a tough outer membrane called the dura (tough) mater (mother).

Spinal Anatomy and the Major Types of Spinal Stenosis

  • Foraminal stenosis. As the nerve root is about to leave the canal through a side hole (lateral foramen), a bone spur (osteophyte) that has already developed from a degenerating disc can press on that nerve root. This type of stenosis is also called lateral spinal stenosis, which is by far the most common form of spinal stenosis. 72% of cases of foraminal stenosis occur at the lowest lumbar level. With this type of lumbar stenosis, the emerging nerve root is trapped (thus comprising a major part of the sciatic nerve).
  • Central stenosis. A choking of the central canal (called central stenosis) in the lumbar (low back) area can compress the sack containing the horse’s tail (cauda equina or cauda equine) bundle of loose nerve filaments. Central spinal stenosis is more common at the second from the lowest lumbar spinal level and higher, and is largely caused by a bulging of the disc margin plus a major overgrowth or redundancy of a ligament (ligamentum flavum) that is there to help protect the dura. This overgrowth is caused by segmental instability, usually from a degenerating disc between adjacent vertebrae. The ligament arises from under the flat laminas of the vertebrae and the inside part of the facet joints (stabilizing joints located on each side at the back of the spine segments).
  • Far lateral stenosis. After the nerve has left the spinal canal it can also be compressed beyond the foramen by either a bony spur protrusion, bulging disc, or herniated disc. When this happens, it is called lateral stenosis.

These differences in spine anatomy may result in similar symptoms, which is why all forms of stenosis are typically referred to as simply spinal stenosis.

However, if spinal stenosis surgery is to be performed, the differences are very important in guiding the surgeon. That is, the bad spot(s) must be exactly known in advance to guide the approach for its proper treatment or removal.

Generally speaking, the various types of spinal stenosis produce similar symptoms.

The most common symptoms of lumbar spinal stenosis include leg pain (sciatica) that may be accompanied by:

  • Low back pain
  • Leg numbness and tingling
  • Limitations in walking.

Leg pain with walking (claudication) can be caused by either arterial circulatory insufficiency (vascular claudication) or from spinal stenosis (neurogenic or pseudo-claudication). Leg pain from either condition will go away with rest, but with spinal stenosis the patient usually has to sit down for a few minutes to ease the leg and often low back pain, whereas leg pain from vascular claudication will go away if the patient simply stops walking.

Although occasionally the leg pain and stenosis symptoms will come on acutely, they generally develop over the course of several years. The longer a patient with spinal stenosis stands or walks, the worse the leg pain will get.

Flexing forward or sitting will open up the spinal canal and relieve the leg pain and other symptoms, but they recur if the patient gets back into an upright posture. Numbness and tingling can accompany the pain, but true weakness is a rare symptom of spinal stenosis. An older person leaning over the handle of their shopping cart while making short stumbling steps often has spinal stenosis.

Overview of Lumbar Spinal Stenosis Symptoms

Overall, lumbar spinal stenosis symptoms are often characterized as:

  • Developing slowly over time
  • Coming and going, as opposed to continuous pain
  • Occurring during certain activities (such as walking) and/or positions (such as standing upright)
  • Being relieved by rest (sitting or lying down) and/or any flexed forward position.

Spinal Stenosis Diagnosis

Diagnostic imaging studies for patients with cervical stenosis or lumbar stenosis include either an MRI scan or a CT scan with myelogram (using an x-ray dye in the spinal sack fluid), and sometimes both. CT scans that are plain or not enhanced are of limited value unless made with very fine segmental scan slices.

It can be shown that each form of spinal stenosis has a dynamic (changing) effect on nerve compression, such as when bearing weight. Due to this changing compression, spinal stenosis symptoms vary from time to time and the physical examination generally will not show any neurological deficits or motor weakness. Some recent scanning methods allow the upright body position to study the effects of spinal loading.

Depending on the severity of symptoms, spinal stenosis can often be managed through non-surgical treatments.

The three most common non-surgical spinal stenosis treatments include:

  • Exercise
  • Activity modification
  • Epidural injections

Non-surgical Treatment for Spinal Stenosis

Non-surgical spinal stenosis treatment options for patients may include:

Exercises for Spinal Stenosis Video

  • Exercises. Although a suitable program of spinal stenosis exercises may be helpful in the hands of a good physical therapist, it is not curative. Even though stenosis exercises are not a cure, however, it is very important for patients to remain active as tolerated and not additionally debilitated from inactivity; therefore, an appropriate spinal stenosis exercise program is a key part of any treatment program.
  • Activity modification. With this treatment for stenosis, patients are usually counseled to avoid activities that cause adverse spinal stenosis symptoms. Patients are typically more comfortable while flexed forward. Examples of activity modification for treatment of spinal stenosis might include: walking while bent over and leaning on a walker or shopping cart instead of walking upright; stationary biking (leaning forward on the handlebars) instead of walking for exercise; sitting in a recliner instead of on a straight-back chair.

Epidural Steroid Injection Video

Additional Treatments for Spinal Stenosis

Anti-inflammatory medication (such as aspirin or ibuprofen) may be helpful in treating spinal stenosis. Some physicians recommend a multiple B-complex vitamin with 1200 mcg of folic acid daily, but this has not been substantiated in the medical literature as an effective treatment for stenosis.

Some people may successfully manage the symptoms of spinal stenosis with the non-surgical therapies either for a period of time or indefinitely. The key in choosing whether or not to have surgery is the degree of physical disability and disabling pain from lumbar spinal stenosis.

As a guideline, when the (usually elderly) patient can no longer walk sufficiently to care for himself or herself (such as to go shopping for essentials), then lumbar spinal stenosis surgery is usually recommended. Surgery for lumbar stenosis is mainly designed to increase a patient’s activity tolerance, so he or she can do more activity with less pain.

Cervical foramina stenosis can be pinpointed not only by the CT and MRI scans, but by injecting the suspicious nerve with a small volume of about 2 dozen drops of local anesthetic (selective nerve root block). After the injection a remission of the symptoms of cervical spinal stenosis when walking, along with true temporary weakness of the limb, is clinically diagnostic and helps the patient decide about stenosis surgery.