Robert A. Hayden, DC, PhD, FICC
The question often arises in a chiropractic office, either when someone else uses the term with a patient or when I need to use it to describe what I see from the history and physical exam. The question: “What is stenosis?”
The word sounds threatening because it has three syllables. Have you ever noticed that the amount of pain, expense, and personal danger associated with the condition is directly proportional to the number of syllables in the name?
Stenosisis the term we use to describe what happens when a hole is too small. It is used in cardiovascular discussions when blood vessels are clogged with plaques or clots, making them smaller in diameter and more resistant to blood flow. In musculoskeletal terms, stenosis usually refers a hole through which nerves must pass. When those holes are too small, nerves may become pressurized, leading to pain, numbness, tingling, and/or muscle weakness in the areas served by those nerves.
Patients with lumbar spinal stenosis—one of the most common reasons for spinal surgery in seniors—are commonly recognized by a bent-forward, shuffling posture and a characteristic small-step gait. Stenosis surgery, however, is a major procedure that is recommended only when conservative methods of care aren’t effective—or when stenosis is caused by such things as tumors or accompanied by intolerable pain or severe neurological problems, such as loss of bowel and bladder function.
Spinal stenosis is created by the narrowing of the spinal canal. This narrowing may be caused by mechanical problems or by abnormalities in the aging (“high-mileage”) spine. It may or may not result in low-back pain, limping, and numbness and tingling in the legs. Stenosis is often a degenerative condition. It may exist for years without causing pain or discomfort, waiting for a fall or an accident to trigger characteristic stenotic pain.
Numerous factors can cause stenosis, such as thickened ligaments, expanding infection, abscess, a congenital or developmental anomaly, degenerative changes, vertebral fractures or dislocations, or a spinal cord tumor. Other conditions, such as a herniated disc, can mimic stenosis.
While herniated discs usually cause rapid and acute muscle spasm, discomfort caused by stenosis builds gradually. Other conditions that can be confused with stenosis include vascular claudication (temporary loss of blood flow), peripheral vascular disease, and abdominal aortic aneurysms (BTW—I screen all seniors for abdominal aneurysms, and occasionally we find them). Claudication—pain triggered by walking—caused by vascular disease most often occurs after walking a fixed distance. Patients with spinal stenosis, however, walk variable distances before symptoms set in. Activities like riding a bicycle and walking up a hill can cause pain in patients with vascular claudication, but not in those with stenosis. On the other hand, standing makes pain worse for stenotic patients, while it relieves vascular claudication.
How is stenosis diagnosed? Spinal stenosis can be diagnosed based on the history of symptoms, a physical examination, and imaging tests. An MRI is a very poor predictor of future disability in stenosis. An electrodiagnostic study is more dependable for information on a stenotic spine.
Although degeneration is the most common cause of the condition, spinal stenosis can also result from long-term steroid use. Degenerative stenosis also has multiple contributing factors, including disc degeneration, disc bulging, bone spur formation around the vertebrae and the facets, thickening of the soft tissues, and bulging around the disc. Some anatomical factors, such as the enlarged, weakened bones caused by Paget’s disease, can complicate both the degenerative process and treatment.
Speaking of treatment, what can we do? How is stenosis treated? There are three basic treatment approaches to spinal stenosis: the conservative medical approach, which frequently involves bed rest, analgesics, local heat, and muscle relaxants; the conservative chiropractic approach, which includes manipulation, exercise and self-care techniques; and surgery. The source of the stenosis often dictates the treatment.
Although medications can provide pain relief, those powerful enough to deaden the pain can also exacerbate patients’ already compromised sense of balance. When the patient loses bowel or bladder control, suffers from intolerable leg pain and claudication, and has progressive loss of function or spinal cord tumors, surgery is the first and only option.
The standard stenosis surgical procedure usually involves opening the spinal canal and decompressing the neural elements by removing the bony structures that contribute to canal narrowing. Although many patients do fairly well after the surgery, the symptoms are likely to return after a period of time. Recent studies show that although stenosis surgery will often have good results up to two years, in the long run, outcomes are much the same between surgery and conservative care.
Some surgeries are far from satisfactory and have to be repeated years later. Surgery is a complicated procedure that irreversibly changes the structure of the back. In many mild and moderate cases of stenosis, however, non-invasive conservative care, such as the chiropractic approach, can help lessen pain and discomfort, maintain joint mobility, and allow the patient to keep a reasonable lifestyle, at least for some time.
The chiropractic approach includes various forms of spinal decompression. There is a very good track record in containing and controlling the symptoms of stenosis. I have had patients return to a normal lifestyle after appropriate treatment. We also use physiotherapy, such as ultrasound and electrotherapy, to control and decrease pain while we are addressing the cause.
Home exercises are a major part of the conservative treatment program. Recommended four or five times a week, the exercises, such as bicycle riding or lying on the side and grasping the knees with the arms, focus on flexing the spine in a forward position—stretching and strengthening the lower back and stomach muscles and improving muscle strength. Exercises designed to mobilize the involved nerves have been found to be particularly helpful.
Ultimately, stenosis is a chronic condition that cannot be “cured,” but it often can be improved, and improvement can be maintained over the long term. Patients can work with a health care provider, such as a doctor of chiropractic, to reduce symptoms and improve their quality of life. So, small holes do not necessarily lead to closed doors.