Spinal stenosis is a condition in which open spaces within the spine become narrowed, causing pressure on the spinal cord and nerves of the spine. It is caused by degenerative narrowing of the spinal canal, due to aging and degeneration of the spine. This results in pain from pinched nerve roots or compression on the spinal cord itself. The symptoms may include neuropathic symptoms in the leg, including numbness, cramping, or weakness, with pain radiating down the leg, known as Neurogenic claudication. This is distinguished from vascular claudication, which is when the claudication stems from a circulatory problem, not a neural problem.
The cause is thought to be reduced blood flow to the lumbosacral nerve roots secondary to compression from surrounding structures, such as enlarged facet joints, thickening of the ligamentum flavum, bony spurs in the spinal canal, and scar tissue, herniated discs, or spondylolisthesis (misalignment of the vertebral bodies). Spinal stenosis can be a natural result of aging, as the spinal canal becomes compressed through years of wear and tear. In other cases, spinal stenosis can be attributed to a specific cause such as an injury, accident, or a related spine condition such as a herniated disc.
Bone spurs - Bone spurs can form between the vertebrae in anyone as they age, and they usually occur in those over 40.
Arthritis - Osteoarthritis is a common condition among those over 50. It can cause disc degeneration, bone spurs, and overgrowth of ligament that can lead to spinal stenosis. Rheumatoid arthritis is a less common cause of spinal stenosis, although the inflammation it causes can create pressure (usually in the neck) that leads to stenosis.
Degenerative spondylolisthesis and degenerative scoliosis (curvature of the spine) - Degenerative spondylolisthesis (slippage of one vertebra over another) is often caused by spinal degeneration. Frequently, this is seen with lumbar spinal stenosis.
Herniated disc - Herniated discs, also known as slipped or ruptured discs, occur when the cushions in the spine that act as shock absorbers become weakened. Slipped discs have various causes, including age, obesity, and injury. When a disc ruptures, it may put pressure on the spinal cord or nerves, and may cause spinal stenosis. Read more about herniated discs.
Injuries - Trauma to the spine can cause vertebrae fractures or dislocations, which in turn can cause damage to the spine canal. These injuries can come from sports, car accidents, or falls.
Tumors - Tumors are abnormal growths of soft tissue which can occur in the spinal canal. The growths put pressure on the spinal cord and vertebrae, and can lead to bone loss and displacement.
Neurogenic claudication can be bilateral or unilateral calf, buttock, or thigh discomfort, pain or weakness. In some patients, it is precipitated by walking and prolonged standing. The pain is classically relieved by a change in position or bending forward at the waist and not simply relieved by rest, as in vascular claudication. Therefore, patients with neurogenic intermittent claudication have less disability in climbing steps, pushing carts (shopping cart sign) and cycling. In severe conditions, some patients with severe compression of the nerve roots, pain is not intermittent but painfully persistent.
The non-surgical treatment of spinal stenosis involves exercise, and improvement of flexibility. Exercises tailored by an experienced physical therapist are helpful, but not curative. There are activities that increase symptoms of spinal stenosis, which often involve forward flexion when it can be substituted for upright movement. Patients appear to achieve some relief when flexed forward. Anti-inflammatory and neuropathic medications may relieve the pain.
Epidural injections are a key aspect to the nonsurgical treatment of spinal stenosis. This consists of an infection of cortisone (corticosteroid) into the space outside the dura of the spinal cord (the epidural space). Studies have shown that injections into the epidural space may alleviate pain in half of cases of spinal stenosis, and up to four injections over 12 months may be tried. The key factors in the decision about whether or not to have surgery include the severity of pain and the ability to improve symptoms with non-surgical treatment.
For refractory pain and when surgery is not an option, neuromodulation is also a equally effective therapy for this pain, including spinal cord stimulation and intrathecal delivery of medication.