In the medical field, stenosis means the abnormal narrowing of a body channel. When combined with the word spinal, it defines a narrowing of the bone channel occupied by the spinal nerves or the spinal cord.
While the narrowing may occur at different parts of the spine, the symptoms of nerve compression are often similar. That is why specialists often will perform testing to determine the cause and location of the narrowing.
Lumbar vs. Cervical Stenosis
The lower back develops lumbar stenosis, while the neck develops cervical stenosis.
- Lumbar Spinal Stenosis
In lumbar stenosis, the spinal nerve roots in the lower back become compressed 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 often mimics symptoms of vascular insufficiency. Both conditions can cause claudication, which means leg pain with walking. If vascular studies identify normal blood flow, and there is confirmation of spinal stenosis on diagnostic testing, the symptoms are then called neurogenic claudication. In the classic description, people with spinal stenosis will describe an onset of leg pain, or weakness with walking, but with relief of symptoms with sitting. Many will also describe increased tolerance to walking when flexed forward, such as when walking while leaning forward on a shopping cart.While lumbar spinal stenosis most often occurs at the L4-L5 and L3-L4 levels, it can occur any level in the spine. The degenerative cascade may eventually effect most of the vertebral segments of the lumbar spine.
- Cervical Stenosis
Spinal stenosis pain in the neck is called cervical spinal stenosis. This condition means that there is potential compression of the spinal cord. Unfortunately, the spinal cord compression can lead to serious problems such as extreme weakness, or even paralysis. With cervical stenosis, anyone who develops signs of spinal cord compression (myelopathy) may need more invasive treatment, such as surgery.
Thoracic stenosis can also occur, but is less common. The thoracic part of the spine is the middle/upper portion of the spine, and mainly consists of the vertebrae that are attached to the rib cage. This stable and strong part of the spine allows for minimal movement, which is why degenerative conditions such as spinal stenosis are less likely to develop.
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. As it is a gradual process and rarely causes immediate symptoms, the subtle changes of spinal stenosis often result in a gradual decrease in physical activity, and a development of a more kyphotic or forward flexed posture.
This gradual accommodation may be evident when looking at a series of oneself in pictures – over the course of several years—after around age 50. It is typical to start stooping forward more and become less active as effects of spinal stenosis increase.
When learning about spinal stenosis, it is helpful to have a clear visual of spinal anatomy and how spinal stenosis develops.
The vertebral column in the spine and sacrum (at the bottom of the spine) are like a stack of bony blocks that serve to support the body.
Each of these bones 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 (the bone channel described above) through which the spinal cord descends, and holes to each side of the canal to allow emergence of spinal nerves at each level. These holes are call the neuro-foramen.
How Spinal Stenosis Affects the Spine
Normally, there is ample space for spinal canal and for the nerve roots as they exit the spine through the neuro-foramen. With spinal stenosis, however, development of bony growths from osteoarthritis and/or other degenerative changes constrict the space for the spinal cord and/or spinal nerves.
The spinal cord stops at the upper part of the low back, usually at about the T12-L1 level. Individual nerves then extend off the end of the spinal cord and travel down the central canal, and exit the spinal canal through those neuro-foramen. The spinal cord and the individual nerves in the spinal canal move within a fluid-filled sac. It is like the spinal cord and the nerves are encased in a garden hose. In this manner, the spinal cord and the nerves can bend along with the spine, and still be protected within that garden hose. The strong outer membrane that encases the cord and the nerve is called the dura (tough) mater (mother).
The area where the nerves extend off the spinal cord is called the cauda equina, as it looks like a horses tail. While rare, it is possible for lumbar spinal stenosis affect the cauda equina and cause a condition known as cauda equina syndrome. This is a serious medical condition requiring immediate medical attention.
There are a number of potential symptoms of spinal stenosis, and one’s specific symptoms are mainly determined by the location and severity of the stenosis in the spine.
Common Spinal Stenosis Symptoms
Overall, spinal stenosis symptoms are often characterized as:
- Developing slowly over time, or slow onset
- Coming and going, as opposed to continuous pain
- Occurring during certain activities (such as walking for lumbar stenosis, or biking while holding the head upright) and/or positions (such as standing upright for lumbar stenosis)
- Feeling relieved by rest (sitting or lying down) and/or any flexed forward position.
Lumbar Stenosis Symptoms
When stenosis has developed in the lower back (lumbar spine), leg pain with walking may develop.
Leg pain with walking is medically known as claudication, and it 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.
For lumbar stenosis, flexing forward or sitting will open up the spinal canal by stretching the ligamentum flavum and will relieve the leg pain and other symptoms, but the symptoms will 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.
Spinal Stenosis Diagnosis
Diagnostic imaging studies for patients with any type of spinal stenosis include either an MRI scan or a CT scan with myelogram (using an X-ray dye in the spinal sac fluid), and sometimes both. Plain CT scans can better identify bony causes of spinal stenosis, but cannot give the same detail for soft tissue causes of stenosis such as disc bulges, disc herniations, and ligament hypertrophy. 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. Certain activities and body position may trigger the symptoms.
There is a wide range of nonoperative treatments for spinal stenosis. The more common options include:
- Exercises. A suitable program of physical therapy and exercise is a component of almost every spinal stenosis treatment program. While the spinal stenosis exercises are not a cure, it is important for patients to remain active as tolerated and not become additionally debilitated from inactivity.The treating physician may prescribe a supervised physical therapy program. After a period of physical therapy instruction, most people can then transition to their own exercise program. The key is to start slowly, and build strength and tolerance over time.
- Activity modification. Patients are usually counseled to avoid activities that worsen their spinal stenosis symptoms. For lumbar stenosis, patients are typically more comfortable while flexed forward. For example, recommended activity modification 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.
Are you currently suffering from spinal or cervical stenosis? Call our office at (304) 263-4927 today to schedule an appointment for physical therapy. Dr Terry Chambers is a Board certified chiropractor and acupuncturist licensed in WV.