Canal stenosis is the narrowing of the canal through which the spinal cord and nerves travel. It can produce neurological and/or pain symptoms and is often indicated as a cause or contributor to sciatica (radicular pain). At times it will be considered as a cause of back pain when associated neurological features are present, such as leg or bowel/bladder weakness. Canal stenosis can be congenital and/or acquired. The combination of disc degeneration, disc protrusion, bone spurs at the back and sides of the vertebrae, facet joint arthritis, and ligament damage can cause Canal Stenosis over time.
The typical presentation of canal stenosis is leg pain made worse by walking. This comes about because one or more nerves are squashed where they protrude from the spinal canal. Walking not only causes mechanical pressure on the nerve, but also causes increased blood flow through the region, which will aggravate the symptoms. If you experience pain in your legs when you walk, there are three primary causes a doctor will consider. Only one is caused by canal stenosis, and it’s called spinal claudication. Claudication simply means pain in the legs when walking. The other two, vascular claudication, and hip arthritis are unrelated to Canal Stenosis. Your doctor will attempt to diagnose which cause is most likely in your case.
Canal stenosis is most common as a cause of pain in the elderly. However, it is difficult to pinpoint it as a cause for pain because it’s possible to have the condition and feel no pain symptoms. Just because it exists on a scan does not imply that it is the cause of the pain. To further complicate the situation, Canal Stenosis can be a significant factor in the presence of other symptoms. Any condition that compromises the spinal canal, sciatica from disc herniation for example, will be exaggerated by Canal Stenosis.
Pain from spinal claudication is activated by walking and relieved by rest. Relief tends to be best achieved by sitting, lying or bending forwards. The pain generally takes minutes to subside. Pain can occur in any part of the leg. Common sites include the calf, outer leg, front of thigh, and foot. The pain is typically localised and at times can be associated with local pins and needles.
It can be difficult to differentiate between the possible origins of pain when walking. One way to differentiate is to perform a caudal epidural with low concentration anaesthetic and then see if walking is then a lot easier (during the time the anaesthetic is active). If pain is abolished or significantly relieved, then the pain is more likely derived from the spinal canal and from the Canal Stenosis.
By the time a person with leg pain comes to a pain clinic the usual range of conservative management has often been tried. The procedures that address the local problems in the spine are epidural injections and surgery. Treatment options include:
a) Exercise: Although walking can be painful it does not cause further injury. Some people become frightened to walk, fearing that they are promoting more damage. You won’t. Stretch your back, pelvis, hip and leg muscles. They might benefit from hydrotherapy or even light gym work.
b) Medication: analgesics and anti-neuropathic pain drugs may be issued by your doctor.
c) Physical Therapy: Local massage, back mobilisation and exercise prescription are options.
d) Acupuncture / local injections into tender points is another possible treatment option.
e) Epidural injection: An epidural can help diagnose the specific cause of your pain and also be therapeutic at the same time.
f) Surgery: The presence of neurological symptoms such as numbness may indicate the need for surgery. Otherwise, the need for surgery is relative. Severe pain that is unrelieved by other treatments is the most common indicator that surgery may be needed. Surgical results for leg pain are good. However, any low back pain is frequently not helped (about 65%-85% satisfaction rate).The outcome for overweight people is not as good.
g) Neuromodulation with spinal cord stimulation: Especially for people who are unfit for surgery.