Lumbar spinal stenosis, the narrowing of the spinal canal in the lower back, is the most common reason for surgery in people over the age of 60. This is because the stenosis is most commonly caused by a degenerative process and arthritic changes to the intervertebral discs, ligaments and joints. As the spinal canal narrows, the nerves can be affected and cause a variety of symptoms, some of which can be painful and severe.
The spine is divided into five regions. The cervical vertebrae are the first seven vertebrae and are located in the neck. The thoracic region consists of the next 12 vertebrae. The lumbar region is the lowest section of five vertebrae. These vertebrae are larger, as they support much of the body's weight, which also means that the lumbar region is most prone to the degenerative processes. Symptoms produced by conditions involving the lumbar region can span beyond the back and spine.
Pain in the lower back is second only to headaches as the most common medical complaint. The pain can be acute where it is caused by an injury, happens suddenly and is short lived. It also can be recurrent where the pain returns over and over or chronic in which the pain lasts for at least three months and does not improve with medication. The cause of the back pain is attributed to the nerves being compressed by the narrowing of the spinal canal.
When the nerves contained in the lower part of the back are compressed, the legs can exhibit symptoms. Pain can radiate from the lower back down the legs, which can be so severe that it is incapacitating and causes difficulty walking. Lumbar stenosis also can cause a tingling sensation in the legs, which is known as paresthesias. Leg weakness is also a common symptom.
Bladder and Bowel Symptoms
Lumbar stenosis that results in compressed nerves can cause disturbances in the function of internal organs, most commonly the bladder or bowels. The damage to the nerves can cause urinary incontinence or a change in bowels, such as constipation.
Degenerative spondiylolisthesis is a disorder of the spine, usually occurring in the lumbar region, marked by one vertebra slipping out of place so that it is pushed forward of the one below it. This condition can produce symptoms similar to lumbar spinal stenosis including lower back pain, leg pain and weakness.