Within the cervical vertebra, a canal exists through which the spinal cord passes. As a part of the normal aging process, discs lose their water content and begin to bulge. In some patients, however, the bulging of the disc and other arthritic changes between the vertebrae constrict the space through which the spinal cord and nerve roots pass. This narrowing results in compression of the spinal cord and nerve roots— called cervical narrow canal or “stenosis”.
Cervical myelopathy: The compression of the cord results in functional loss in the upper and lower limbs. Cervical myelopathy has a progressive course. Handwriting detoriation, dropping objects, and failure to button are frequent complaints. Loss of balance may also occur. In extreme cases, severe weakness and numbness in the arms and legs may exist. More rarely, there may be changes in bowel or bladder control.
Cervical radiculopathy: The compression of the nerve roots resulting in functional loss in a certain part of the extremity. Cervical radiculopathy is pain radiating pain from the neck to the arms, forearms or hands. Muscular weakness may associate in the corresponding muscle groups.
What is the Natural Course of Cervical Myelopathy and Cervical Radiculopathy?
The duration of symptoms suggests the natural course. In most the acute cases, symptoms of pain, numbness, and weakness generally disappear within 6-12 weeks. In sub-acute and chronic patients, however, the outcomes vary. In approximately one third of patients, physical therapy and nonoperative care can cause the pain to disappear or reach a level that is tolerable.
For some patients, the pain may be intolerable, thus, requiring further treatment. Although the “natural course” is more uncertain in clinically evident cervical myelopathies, there is a general aggreement that the myelopathy symptoms will progress over time. The rate, timing and rapidity of such a progression, however, are not predictable. Approximately 75 percent of patients show a staged deterioration. In between these “stages,” there may be limited time periods that the symptoms improve. Twenty percent of the patients have a constant worsening, and 5 percenthave rapid worsening.
How are Cervical Myelopathy and Radiculopathy Diagnosed?
If a stubborn or worsening numbness or weakness is present in your arms and/or legs, you should refer to a spine surgeon. Medical history followed by a physical examination to check the functions of the nerves in your arms or legs, and to check your balance and assess your gait will be performed.
Then radiographic evaluation may follow. X-rays may reveal degenerative changes in the disc spaces or the facet joints. There might also be a slight slippage between the cervical vertebrae. Magnetic resonance imaging (MRI) enables visualization of the soft tissues on the spinal cord or nerve roots that have a possibility of compression. Computed tomography (CT) myelogram that uses contrast material may also be used to enhance viewing the spinal cord.
Electromyogram (EMG) and nerve conduction studies may be used to evaluate the functions of the cord and nerves. These studies help differentiate cervical radiculopathy (illness due to nerve roots) from other nerve diseases in the arm and forearm such as carpal tunnel. Somatic sensory evoked potentials (SSEP) are electrical tests that evaluate signal transduction in the spinal cord, and can be performed in some patients with cervical myelopathy. Follow this link to read about the treatment of cervical spinal stenosis.