Degenerative cervical myelopathy, often called DCM, is a progressive condition affecting the spinal cord in the neck. It develops when the spinal canal, the bony channel protecting the spinal cord, narrows and squeezes the cord. This compression is not from a sudden injury but is a consequence of gradual, age-related “wear and tear” changes in the cervical spine. When the narrowing becomes significant enough to put pressure on the spinal cord, it can disrupt nerve signals between the brain and the rest of the body. This interference leads to a range of neurological symptoms that develop slowly and worsen over time, making DCM the most common type of spinal cord dysfunction in adults.
Underlying Causes of Spinal Cord Compression
The compression of the spinal cord in DCM stems from a combination of age-related changes. One of the primary drivers is cervical spondylosis, which is arthritis of the neck. This process involves the gradual deterioration of the vertebrae and the intervertebral discs, the cushion-like pads that sit between them. As these discs age, they lose water content, shrink in height, and can bulge outwards, reducing space within the spinal canal.
In response to disc degeneration, the body often creates extra bone, known as osteophytes or bone spurs. While intended to reinforce the spine, these osteophytes can protrude into the spinal canal, further narrowing the space for the spinal cord.
Another factor is the behavior of the ligaments that support the spine. With age, ligaments such as the ligamentum flavum can thicken and lose their flexibility. This stiffening and enlargement, known as hypertrophy, can cause the ligaments to buckle into the spinal canal, adding another source of pressure.
Common Symptoms and Early Signs
The symptoms of degenerative cervical myelopathy often develop insidiously and can vary greatly from person to person. One of the most characteristic signs is a change in walking ability, or gait. Individuals may develop an unsteady, wide-based walk as they subconsciously try to improve their stability and prevent falls. This balance disturbance happens because the compressed spinal cord struggles to transmit sensory information about the body’s position from the legs to the brain.
A decline in fine motor skills is another frequent symptom. People may notice increasing clumsiness in their hands, making everyday tasks that require dexterity difficult, like buttoning a shirt, writing, or picking up small objects. This loss of coordination is a direct result of the disrupted nerve signals that control the intricate muscles of the hands and fingers.
Sensory changes are also common, often appearing as numbness, tingling, or a “pins and needles” sensation. These feelings, medically termed paresthesia, frequently start in the fingertips and can spread through the hands and up the arms. While neck pain and stiffness can be present, they are not universal symptoms, and their absence does not rule out the condition.
The Diagnostic Process
Diagnosing degenerative cervical myelopathy begins with a thorough discussion of the patient’s symptoms and medical history. A physician will ask detailed questions about the onset and progression of issues like hand clumsiness, balance problems, or sensory changes. This is followed by a comprehensive physical and neurological examination to look for objective signs of spinal cord dysfunction.
During the physical exam, the doctor will observe the patient’s gait and test muscle strength, sensation, and reflexes in the arms and legs. Specific neurological tests are performed to detect signs of upper motor neuron involvement. These may include checking for a positive Hoffman’s sign, where flicking the middle finger’s nail causes an involuntary flexion of the thumb and index finger, or the Babinski sign, where stroking the sole of the foot causes the big toe to extend upward.
While the physical exam provides strong clues, imaging studies are necessary to confirm the diagnosis and assess the compression’s severity. Magnetic Resonance Imaging (MRI) is the most definitive imaging test for DCM. An MRI provides detailed images of the spinal cord and surrounding soft tissues, clearly showing the location and extent of the compression.
Medical and Surgical Interventions
The management strategy for degenerative cervical myelopathy depends on the severity of the symptoms. For individuals with mild forms of the condition, non-surgical approaches may be considered. These conservative treatments, such as physical therapy, are aimed at managing symptoms like pain or stiffness but do not address the underlying spinal cord compression.
Because the condition is often progressive, surgery is the primary treatment for patients with moderate to severe symptoms. The goal of surgery is decompression—to physically create more space for the spinal cord and relieve the pressure causing the neurological symptoms. This aims to stop the progression of neurological decline and, in some cases, may allow for functional recovery.
Surgeons can perform this decompression from either the front (anterior) or the back (posterior) of the neck. An anterior cervical discectomy and fusion (ACDF) is a common procedure where the surgeon removes a problematic disc and bone spurs from the front. Posterior approaches include a laminectomy, which involves removing a section of bone from the back of the vertebra, or a laminoplasty, which expands the spinal canal.