The lumbar spine is made up of five vertebral bodies in the lower back. Nerves coming off the spinal cord travel though the spinal canal and exit the canal through small openings on the sides of the vertebral called foramen. Lumbar stenosis (spinal stenosis) is a condition whereby either the spinal canal (central stenosis) or vertebral foramen (foraminal stenosis) becomes narrowed. If the narrowing is substantial, it causes compression of the nerves, which causes the painful symptoms of lumbar spinal stenosis. The most common cause of lumbar spinal stenosis is degenerative arthritis. As with other joints in the body arthritis commonly occurs in the spine as part of the normal ageing process. This can lead to loss of the cartilage between the bones at the joints, formation of bone spurs (osteophytes), loss of the normal height of the discs between the vertebrae of the spine (degenerative disc disease), and overgrowth (hypertrophy) of the ligamentous structures. Each of these processes reduces the normal space available for the nerves and can directly press on nerve tissues to cause lumbar spinal stenosis. Lumbar spinal stenosis can also be caused by other conditions that decrease the space of the spinal canal or vertebral foramen. These can include: - tumor,
- infection, and
- various metabolic bone disorders, such as Paget's disease of bone.
These causes are much less common than degenerative arthritis. Lumbar spinal stenosis can cause: In most cases the symptoms improve when the patient is sitting or leaning forward. Typically, painful sensations shoot down the legs with continued walking, and diminish with resting. Standing and bending backwards can make the symptoms worse. This is because bending forward increases the space in the spinal canal and vertebral foramen, while bending backward decrease the space. It more comfortable for patients to sit or lean forward and are unable to walk for long distances. Patients often state their symptoms are improved when bending forward while walking with the support of a walker or shopping cart. In most cases the symptoms gradually worsen with time. This is because degenerative arthritis is a progressive disease that gradually becomes more severe with time. If left untreated the compression on the nerves from lumbar spinal stenosis can lead to increasing weakness and loss of function of the legs. It can also lead to loss of bowel and bladder control and loss of sexual function. Your doctor can help determine if your symptoms are from lumbar spinal stenosis or a different condition. Many other disorders can cause similar symptoms including: http://www.aafp.org/afp/980415ap/alvarez.html http://orthoinfo.aaos.org/topic.cfm?topic=A00329 http://www.neurosurgerytoday.org/what/patient_e/lumbar.asp http://www.spine-health.com/dir/spinsten.html ©2005MissDawnMaria |