Cervical stenosis occurs when either the cervical spinal canal becomes narrowed, termed "central stenosis", or when lateral nerve foremen become narrow, termed "lateral stenosis". Both cause neck pain, although the spinal cord is injured with central stenosis, whereas the cervical nerve roots are injured with lateral stenosis. Sometimes, patients suffer from both types. The symptoms associated with both types differ. According to the Colorado Spine Institute, most cases of cervical stenosis develop in patients over age 50 with a history of neck injury or trauma, which results in abnormal wear and aging.
Neck Pain
Cervical stenosis is not nearly as common as lumbar--low back--stenosis, although Dr. Harry Herkowitz notes that 25 percent of patients who suffer in either location have stenosis present in both. Lateral and central cervical stenosis usually both develop slowly over years because degeneration in later life is the main cause. Symptoms rarely appear all at once with degenerative stenosis and are usually initially limited to localized neck pain. Stiffness and achy neck pain is common and frequently not that severe. Neck stiffness can lead to reduced range of motion. It has been estimated that about 5-7 of every 1000 Americans older than 50 years experience symptoms of spinal stenosis and this number will only increase as the population ages.
Shoulder and Arm Pain
As lateral stenosis progresses in the cervical spine, typically by growth of lateral bone spurs and loss of intervertebral disc height, radiculopathy can develop. Radiculopathy is pain caused by compression or irritation of spinal nerve roots. Cervical spine radiculopathy often involves burning and shooting pain into the shoulders and down one or both arms. The shoulder, arms and hands are affected because nerves from the cervical region innervate those areas. Radicular pains are often the result of moderate to severe cervical osteoarthritis and intervertebral disc herniation. Chronic cervical nerve root irritation can lead to increased incidence of carpal tunnel syndrome, which can lead to hand weakness/clumsiness and numbness.
Arm and Hand Weakness
Lateral and central stenosis can have overlapping symptoms as they pertain to the upper limbs. Both types of cervical stenosis can cause numbness in the arms/hands, but weakness and muscle atrophy is usually reserved for central stenosis and injury to the spinal cord. When compression results in cord damage, it is termed "myelopathy" and causes weakness, reduced coordination and loss of fine motor skills—like typing—in the hands. Grip strength also becomes reduced and is often measured by doctors as it is a good indicator of cervical central stenosis and spinal cord injury.
Leg Symptoms
Sometimes, the first symptoms of cervical stenosis to appear is gait and balance disturbances, and patients don’t realize it’s coming from their neck. However, pressure on the cervical spinal cord can affect the nerves and muscles of the legs, leading to weakness, spasticity, reduced reflexes and “jerky” walking patterns. Many people who have such symptoms do show evidence of cervical stenosis on magnetic resonance imaging scans. For example, an adult male without spinal stenosis has a spinal cord diameter of 16-17 mm in the upper and middle cervical levels; a measurement much below this with symptoms would be suggestive of stenosis.
Rare Symptoms
In severe cases of cervical stenosis, loss of bladder and bowel control can arise leading to incontinence, but this is rare. Also rare, is paralysis of the upper and lower limbs.
References
- Colorado Spine Institute
- Spine Universe: Dr. Harry Herkowitz
- "Spine"; A review of the pathophysiology of cervical spondylotic myelopathy with insights for potential novel mechanisms drawn from traumatic spinal cord injury; M.G. Fehlings et al; Dec 15 1998
- "Essentials of Physical Medicine and Rehabilitation"; W.R. Frontera et al; 2008
- "Chiropractic Management of Spine Related Disorders"; Meridel I. Gatterman D.C.; 2001
