By Wendy Haaf
What causes narrowing of the spine, or spinal stenosis, and what are the treatments?
There are two main kinds of spinal stenosis. It can occur in the hollow tube surrounding the spinal cord or in one or more of the foramina—the spaces between each pair of vertebrae through which nerves pass.
Spinal stenosis is usually caused by age-related changes. For example, “arthritic changes can cause abnormal growth of bony tissue called osteophytes, or bone spurs,” explains Maria Rachevitz, an advanced practice physiotherapist and professional leader of the Rapid Access Low Back Clinic at Sunnybrook Hospital in Toronto. Bone spurs develop as a result of continuous wear and tear on the joints associated with aging. The small joints in the spine are covered with smooth cartilage so bones can glide against each other; when this protective layer wears down, spine arthritis develops.
In addition to age, risk factors include genetic predisposition (some people are born with smaller openings), ethnicity, excess body weight, smoking, and occupations involving heavy physical labour.
Most often, spinal stenosis affects the lower back. “It happens four times more often in the lumbar spine,” Rachevitz says. According to a 2022 JAMA article, up to 20 per cent of people aged 60 or older show evidence of lumbar spinal stenosis (LSS) on imaging studies, but 80 per cent don’t experience any symptoms and so don’t need treatment.
However, if the opening gets small enough, it begins to exert pressure on the nerve. This, in turn, is thought to block blood flow to the nerve. The result is “pain, tingling, numbness, or weakness in the leg that gets worse with standing, walking, or bending backward,” Rachevitz says. Typically, sitting or leaning forward can provide relief “because it releases the pressure on the nerves,” she explains. How- ever, symptoms can fluctuate. Spinal stenosis is diagnosed by means of imaging, reviewing symptom pattern, and conducting a physical exam.
As for treatment, “some people get better with conservative management,” Rachevitz says. Physiotherapy is the mainstay, especially for foraminal narrowing. This includes a flexion-based exercise program in combination with core-muscle strengthening (which eases the load on the back) and learning how to modify certain activities. For instance, working out on a stationary bike is usually more comfort- able than walking. When you do walk, bending forward slightly can help ease symptoms.
Certain medications may be useful for managing pain, as well. “Non-steroidal anti-inflammatories such as ibuprofen can help, and there are special neuropathic agents, such as pregabalin and gabapentin, that can help leg pain,” Rachevitz says.
The minority of people whose symptoms get progressively worse or don’t improve with conservative management may require surgery. Called a laminectomy, the operation involves shaving the bony roof off of a portion of the spine. “It’s like making a convertible out of your spine,” Rachevitz says. “That will allow the nerve beneath to breathe. This surgery is very effective for leg pain, numbness, and tingling, but it usually doesn’t help back pain.”
Resources
- You can find exercises for lumbar spinal stenosis at lowbackrac.ca and by searching online for “Dr. Andrea Furlan and spinal stenosis.”
- Videos explaining surgery
- Weighing the pros and cons of surgery.
