Degenerative disease in the spine is a very common age-related disease, which most commonly affects the mid-to-lower lumbar and cervical spines, where the natural curve and flexibility of the spine are most pronounced.  

Those factors increase wear and tear changes in the vertebrae, discs, posterior facet joints and associated ligaments and explain why pain and stiffness are so common in the lower back and neck beginning in midlife and why, past 50 years of age, imaging studies reveal degenerative changes in almost everyone, whether they have symptoms or not.

This week focuses on the cervical spine. 

The degenerative changes observed in the cervical spine are similar to those observed in the lumbosacral spine — disc space narrowing and bulging discs, thickening of the vertebral edges where they meet the discs, similar changes in the posterior facet joints and thickening of spinal ligaments. 

Those pathological changes in the cervical region may crowd the exit foramina for the cervical roots, especially for the C5, C6, C7 nerve roots or less often, the C8 nerve root.

But unlike the lumbosacral region, where the spinal cord ends well above the most affected regions of the spine, degenerative changes in the cervical region may sometimes be severe enough to compress the spinal cord, producing weakness and instability in the legs and adding to weakness in the arms.  

The pain and stiffness in the neck limit flexion, extension and rotation of the neck the last of which can limit the extent to which some drivers can properly check for traffic beside and behind them, a real problem these days where rear and back corner visibility in some cars is so limited — posing a real risk for drivers on busy streets and highways. 

Like the lumbar spine, the pathology seen on imaging studies commonly involves two or more levels — and more, the older we are. This places a premium on the clinical history and examination to figure out which changes in imaging studies are relevant to the patients’ symptoms. 

Tips to which nerve roots are relevant include pain and weakness in the shoulder and shoulder blade muscles for the C5 root, tingling in the thumb, weakness in the biceps and loss of or a reduced biceps reflex for the C6 root, tingling in the index and middle fingers, weakness in the triceps and a lost or a reduced triceps reflex for the C7 root, and for the C8 root, tingling in the baby finger and weakness in the small muscles of the hand.

There are other findings, of course, but those are the most helpful.

Evidence that the spinal cord is compressed is based on weakness in what’s often referred to as a “long-track” distribution — involving flexion of the hip and knee and dorsiflexion and eversion of the ankle and toes, together with a upgoing big toe if the bottom of the foot is stroked accompanied by brisker than normal tendon reflexes in the legs. 

Some patients report that they feel an electric shock sensation extending from their neck and often into their trunk legs when they flex their neck, cough or step down hard on something.

This symptom is proof positive that the spinal cord is affected in the neck, but not the specific cause. 

The point is that examining patients thoroughly is essential to making sense of the patient’s symptoms and clinical findings and determining the best options for treating the symptoms.

What can be done?

For patients with evidence that the spinal cord is compressed and especially if accompanied by weakness in cocking up and everting the feet, which so often lead to tripping and falls, consideration should be given to surgically “decompressing” the spinal cord from the front or back accompanied by fusion to stabilize the cervical spine should that be indicated.

Which approach is best depends on the precise features of each case and frankly, the neurosurgeon. 

In my experience working in major centers in London Ont., Boston and Hamilton, Ont., the most important decision is choosing a spine center with a multidisciplinary approach and expertise to properly assess complex spine cases, whether in the lower back or neck. 

In the spring, there will be a several-week series at the Niagara-on-the-Lake Public Library on the causes of neck and lower back pain and common nerve injuries in the arm and leg. 

Dr. William Brown is a professor of neurology at McMaster University and co-founder of the InfoHealth series at the Niagara-on-the-Lake Public Library.