The vertebrae consist of structures that provide: stability to the spine (vertebral body, discs, ligaments and facet joints), areas for muscles to attach, as well as protection of the nerve and spinal cord as they travel from the brain to the rest of the body. The spinal cord and nerves travel through a protective channel (spinal canal) made up of these components of the vertebra. When there is narrowing within this channel, the spinal cord and nerves may be compressed, leading to spinal cord damage (‘myelopathy’) or nerve pain (‘radiculopathy’). The medical term for this narrowing is ‘spinal stenosis’. Spinal stenosis can affect different regions of the spine. The commonly affected regions are the lower back (lumbar spinal stenosis) and neck (cervical spinal stenosis). Of the two, lumbar stenosis is more common, but cervical stenosis is a more serious condition because of pressure on the spinal cord.
Most cases of spinal stenosis are caused by degenerative conditions (e.g. disc herniation, osteoarthritis, thickening of joints and ligaments), with a small number of people inheriting a predisposition to the condition due to their anatomical make-up.
Symptoms of spinal stenosis are very similar to other conditions causing inflammation or compression of spinal nerves. Sometimes spinal stenosis does not cause any symptoms, however over time, the following symptoms may be experienced:
- Pain (often a 'radiating' type of pain).
- Numbness / tingling.
- Difficulty or heaviness with walking.
Areas affected can include the legs and the lower back (for lumbar stenosis); the arms, neck and shoulders (for cervical stenosis). Symptoms may appear during some form of physical activity. With lumbar stenosis, standing or prolonged walking may make the symptoms worse (‘spinal claudication’), or the symptoms can be very similar to those of sciatica. In some cases, there may also be loss of sexual function, abnormal bladder / bowel function or paralysis. Paralysis is a medical emergency and medical assistance must be sought as soon as possible.
Tests / Diagnosis
The first part of the diagnostic process is a physical examination and a review of symptoms and any medical history. Diagnosis is generally confirmed via x-ray or CT (computed tomography) or MRI (magnetic resonance imaging) scans. Blood tests may also be required to rule out any other potential causes of the symptoms. The symptoms can sometimes be confused with inadequate blood flow to the legs, and so an ultrasound / Doppler test of the blood vessels in the legs may also be done.