Stenosis refers to the narrowing of the transits, in the spine, through which the nerves and the spinal cord travel. Stenosis leads to compression of the nerves and the spinal cord resulting in pain and numbness of the affected region. Depending on the location of stenosis, it can be classified into:
Foraminal stenosis: Stenosis of the neuroforamen results in compression of the spinal nerves roots. Neuroforamen are the empty spaces on either side of each vertebra, through which the spinal nerves travel to different parts of the body.
Central canal stenosis: The spinal canal is a hollow space, within the spinal column, created by the articulation of the different vertebrae; one over the other. It protects the spinal cord. The narrowing of this spinal canal may result in spinal cord compression which is known as central canal stenosis.
Depending on the region of the spine affected, stenosis is broadly classified into cervical stenosis (Neck) and lumbar stenosis (low back).
Stenosis is usually caused by osteoarthritis and degenerative changes in the spine, and is more common in adults above 50 years of age. These degenerative changes are part of the natural ageing process resulting from wear and tear with repetitive use and include herniated or bulging disc, degenerative disc disease, bony outgrowths (osteophytes) and thickening of the spinal ligaments, especially the ligamentum flavum, which may buckle and compress the nerves.
Some patients have a narrow spinal canal right from birth which is referred to as congenital spinal stenosis. A spinal injury, tumor or spine surgery may aggravate the condition.
The symptoms of stenosis vary depending on the area of the spine affected. Cervical stenosis results in neck pain, which may radiate to the shoulders, arms and hands and may also be associated with arm weakness. Lumbar spinal stenosis results in low back pain which may radiate to the buttocks and legs and may be associated with leg weakness. In either case patients may also experience numbness, tingling and pins and needles sensations.
Stenosis is a progressive condition and in severe cases it can cause bladder and bowel dysfunction or paralysis of the lower limbs (paraplegia).
A detailed medical history coupled with physical and neurological examination is essential for an accurate diagnosis. Neurological examination involves the evaluation of reflexes and muscle weakness and helps in identification of any injury. Your doctor may also order an X-ray, MRI or CT for confirmation of the diagnosis. A myelography may also be ordered for better visualization of the nerve compression.
Non-surgical treatment is a preferred approach and includes pain medication such as non-steroidal anti-inflammatory drugs, physical therapy, muscle relaxants and spinal injections. Back braces may also recommend to keep the lower back still and reduce mechanical pain. Acupuncture may be effective in some cases.
Surgery is considered in patients with intolerable pain, spinal instability and neurologic dysfunction. The two commonly performed surgical procedures for treatment of stenosis are laminectomy and spinal fusion. Laminectomy increases the space around the spinal cord and /or spinal nerves by removing bone, bone spurs and ligaments compressing them. It is done either by an open surgery or a minimally invasive approach. In patients with spinal instability due to arthritis, spinal fusion may also be coupled with laminectomy. Spinal fusion involves permanent fusion of two vertebrae with instrumentation such as rods and screws to eliminate movement between them. Most patients undergoing surgery find significant respite in pain, after the procedure.
Consult your surgeon to clarify any concerns you have about stenosis or its management.