Spinal Stenosis


Ajay K. Mathur, M.D.Most likely you have heard of this condition causing low back and neck pain with complaints spilling over into the arms and legs as well.

This is a common problem seen as people age. Like everything else the spine degenerates with age resulting in pressure on the nerve endings in different parts of the spine.

You may be Interested to know that the human spine consists of stacked up cylindrical bony vertebrae separated by soft cushion-like structures called discs which are wedged between each vertebrae and act as very efficient shock absorbers.

There are 33 total vertebrae (7 cervical, 12 thoracic, 5 lumbar1 5 sacral and 4 coccygeal). The sacral and coccygeal vertebrae at the lowest part of the spine are usually fused to form a solid wedge-shaped base which then connects to both hips. The size of these vertebrae gradually increases from top to bottom to progressively bear more weight. The very delicate spinal cord runs down from the brain securely encased in the canal formed by these bony vertebrae.

Spinal stenosis commonly involves the cervical spine (neck) or lumbar spine (low back). The terms osteoarthritis of the spine, lumbar spondylosis, or degenerative joint and disc disease of the spine can be used interchangeably with spinal stenosis.

Signs and symptoms

Persons suffering from spinal stenosis usually complain of calf and leg pain and difficulty walking a distance sometimes referred to as neurogenic claudication. They may have trouble standing in one place for a prolonged period of time. They can also complain of pain, tingling, numbness in the legs depending on the type of nerve that is being pinched in the back or neck.

Muscle spasm, neck and back pain, decreased sensation and weakness in the extremities can also develop. Severe cases of lumbar spinal stenosis called cauda equina syndrome could affect nerves controlling bowel and bladder functions resulting in incontinence. This is considered a serious problem and may need to be dealt with surgery as an emergency.

Causes of spinal stenosis

Some people have a genetically small spinal canal which can cause symptoms of spinal stenosis. Commonly spinal stenosis is caused by wear and tear damage to the spine resulting in the development of bone spurs.

Soft cushions in between the vertebrae also referred to as discs become dry and start cracking and disintegrating with age, resulting in pressure on the nerves in the spine.

Various types of trauma to the spine can cause fractures of the vertebrae, displaced bone fragments damage to the soft cushions or discs resulting in spinal stenosis. Rarely diseases like Pagets disease of the bone and certain tumors of the spinal cord can cause this problem.

Diagnosis and investigations

It is important to get a proper diagnosis as early as possible. A proper history and physical examination by the physician along with corroboration of the diagnoses with certain tests is helpful. Commonly used tests are:
  • X-rays that can show arthritic changes
  • Magnetic resonance imaging (MRI) is a very useful test in detecting most of the causes of spinal stenosis
  • CT scan of the spine can be equally useful if MRI scan cannot be done for some reason
  • Sometimes CT myelogram which involves a CT scan in conjunction with a contrast dye may be needed

Treatment

Best way to treat spinal stenosis is with a multifaceted approach including:
  • Pain relievers and anti-inflammatory medication such as Tylenol, Advil or Aleve
  • Muscle relaxants such as Flexeril
  • Tricyclic antidepressants, such as amitriptyline, can help deal with chronic pain
  • Judicious use of certain pain relieving medications such as Gabapentin, Lyrica or narcotic medications if needed

The above drugs in different combinations along with physical therapy measures seem to work quite well for mild to moderate symptoms. Physical therapy helps to strengthen the muscles in the back, stabilize the spine and improve balance.

Appropriate use of injections containing corticosteroids and a numbing solution into the space around the pinched nerve in the back can be very helpful in combination with the above treatment modalities as well. Steroid injections do not work for everyone and repeated injections are usually not recommended.

If the above treatments are not sufficient to control the symptoms, surgery to relieve the pressure on the nerve endings and ┬Ěstabilize the spine remains an option.

Surgery for spinal stenosis is usually a type of decompressed laminectomy in which pressure on the nerves are released. In some cases the vertebrae may have significant damage and require metal hardware and bone grafting to stabilize the spine called spinal fusion.

Investigative treatments such as use of stem cells and gene therapy are still not mainstream. Alternative therapies can act as an adjunct to conventional treatment such as massage therapy and acupuncture.

Maintaining a normal weight (losing weight if one is overweight), as well as, stretching and strengthening exercises of the spine are all critical to maintain improvement in pain and functional status.