Bilateral Spinal Stenosis
The majority of spinal stenosis is unilateral as it occurs due to wear and tear on the spine throughout life. This means that the damage is often more extensive on one side of the spinal column simply due to a slightly higher degree of activity on one side of the body than the other. Bilateral stenosis, when it does occur, is often due to a congenital abnormality that causes problems through foraminal stenosis or creates a predisposition to develop stenosis with only a small amount of osteophyte growth or disc bulging. Many people with spondylolisthesis find that they develop bilateral foraminal stenosis as the spine slips forward to an equal degree on both sides.
Symptoms of Bilateral Spinal Stenosis
Symptoms of bilateral spinal stenosis are the same as for other types of spinal stenosis but differ due to their presence on both sides of the body. Where a person with unilateral spinal stenosis may have radicular pain in their right arm or sciatica in one leg only, a person with bilateral stenosis suffers from pain on both sides due to nerve compression at either side of the spine. The general causes of bilateral spinal stenosis remain the same, with osteophyte growth and disc bulging or herniation the major culprits.
Rheumatoid arthritis may also be implicated in some cases as this tends to create a symmetrical pattern of arthritic symptoms throughout the body rather than the asymmetry usually observed with osteoarthritis (spondylosis in the spine). Ligament calcification can also cause bilateral spinal stenosis if it puts equal pressure on both sides of the spinal canal, as can whiplash-induced damage on both sides of the cervical vertebrae. Degenerative disc disease may lead to compression of spinal nerves on both the left and right side of the intervertebral space but is more usually confined to a rupture in one direction only. It may be that patients experience bilateral spinal stenosis from disc herniation or osteophyte growth at neighbouring vertebral levels that create similar symptoms.
Diagnosing Bilateral Spinal Stenosis
MRI scans, and CT scans can help to identify possible areas of stenosis in the spine, but X-Rays may require more extensive scrutiny and/or scans from different angles in order to locate bilateral stenosis. Due to the proximity of spinal nerves on either side of the vertebrae, it can be difficult to determine if both sets of nerves are creating symptoms. Selective nerve-root blocks may allow some of the analgesic and anti-inflammatory to diffuse across to the nearby nerve and compromise the results when used diagnostically. Back surgery on one side of the spinal canal may, therefore, not fully address a patient’s symptoms of bilateral stenosis if incorrectly diagnosed.
Bilateral Spinal Stenosis Treatment
Treatment is usually conservative for unilateral spinal stenosis as it is often caused by a bulging or herniated disc that might resolve itself. Bilateral spinal stenosis however, may be considered more likely to require surgical intervention through decompression back surgery as the condition implies some degree of mechanical pathology that is unlikely to be addressed by NSAIDs, physical therapy or rest. Foraminotomy to widen the exit-space of the spinal nerves, discectomy to remove a severely degenerated disc, the X-Stop procedure to restore intervertebral height, or even spinal fusion may be necessary to realign and stabilize the spine and prevent nerve compression.