Cervical Myelopathy (CM) is a neurological condition resulting from chronic compression of the spinal cord within the neck. This disorder is the most common cause of spinal cord dysfunction in adults over the age of 50. The pressure on the spinal cord interferes with signal transmission between the brain and the rest of the body. Understanding if surgery can “cure” this condition requires examining the pathology and the specific aims of the procedure.
Understanding Spinal Cord Compression
Cervical Myelopathy is caused by a narrowing of the spinal canal, known as cervical stenosis. This narrowing typically results from age-related degenerative changes, collectively called Cervical Spondylosis. These changes include the formation of bone spurs, bulging intervertebral discs, and the thickening of surrounding ligaments.
A less common but significant cause is the Ossification of the Posterior Longitudinal Ligament (OPLL), where the ligament along the back of the vertebral bodies turns into rigid bone. Regardless of the exact cause, the resulting compression gradually injures the spinal cord, impairing nerve function. This pathology manifests as a progressive decline in neurological function that is often initially subtle.
The neurological symptoms of CM follow a distinct pattern of decline. Individuals commonly experience gait disturbance, characterized by unsteadiness, balance issues, and a wide-based walking pattern. Fine motor skill loss is frequent, often described as clumsiness or difficulty performing tasks like buttoning a shirt or handling small objects.
Patients may also notice diffuse numbness or tingling in the hands and arms, which is not confined to a single nerve pathway. Muscle weakness in the limbs and changes in reflexes are common findings during a neurological examination.
Diagnostic Process and Treatment Timing
The diagnosis of Cervical Myelopathy is established by correlating a patient’s clinical symptoms with definitive imaging evidence of spinal cord compression. Magnetic Resonance Imaging (MRI) is the primary diagnostic tool, as it provides detailed visualization of the spinal cord, discs, and soft tissues. A Computed Tomography (CT) scan may also be used, particularly to assess the bony structures, such as the presence and extent of bone spurs.
A thorough neurological examination is performed to quantify the severity of the myelopathy and track its progression. Physicians use standardized scales, such as the Modified Japanese Orthopaedic Association (mJOA) scale, to grade the functional deficits related to motor, sensory, and sphincter function. This grading helps determine the urgency of intervention.
The decision regarding treatment timing is a central component of managing this condition. For patients with mild symptoms, a period of close observation, sometimes called “watchful waiting,” may be considered if symptoms are stable. However, the evidence supporting non-surgical management for CM is weak, and the disease typically advances over time.
Timely surgical intervention is recommended for patients presenting with moderate to severe symptoms or progressive neurological decline. A delay in treatment is strongly associated with poorer outcomes, as spinal cord damage can become irreversible. The goal is to decompress the spinal cord before permanent injury occurs.
Goals of Surgical Intervention
Surgery is the only effective treatment for Cervical Myelopathy, and its primary purpose is to halt the progression of neurological decline. The surgical intervention aims for two distinct goals: decompression and stabilization.
Decompression involves removing the anatomical structures that are impinging upon the spinal cord, thereby creating more space within the spinal canal. This may include removing herniated discs, bone spurs, or portions of the vertebrae and thickened ligaments. Relieving this pressure is designed to prevent further injury and allow the spinal cord to recover some function.
The second goal is stabilization, which is often necessary when the decompression procedure creates instability in the cervical spine. Stabilization is typically achieved through spinal fusion, where hardware like plates, rods, and screws are used to connect two or more vertebrae and encourage them to grow together into a single, solid bone segment. This prevents abnormal movement that could re-injure the spinal cord.
Anterior Approaches
Anterior approaches, performed from the front of the neck, include Anterior Cervical Discectomy and Fusion (ACDF) or corpectomy. These procedures involve removing the disc or vertebral body, respectively, to relieve pressure.
Posterior Approaches
Posterior approaches, accessed from the back of the neck, include laminectomy or laminoplasty. A laminectomy involves removing the posterior bony arch (lamina) to widen the spinal canal, often followed by fusion for stability. Laminoplasty is an alternative where the lamina is hinged open and held in a wider position, sometimes avoiding fusion. The specific procedure chosen depends on the anatomy of the compression and the alignment of the cervical spine.
Defining Long-Term Prognosis
Following surgical decompression, the long-term prognosis is positive, with the primary expectation being the prevention of future neurological deterioration. Studies indicate that a large majority of patients, often more than 85 percent, achieve neurological stability or improvement after the procedure. The degree of functional recovery, however, is highly variable.
Reversal of existing symptoms is possible, but this outcome is strongly dependent on the severity and duration of the myelopathy before the operation. Patients with milder symptoms and a shorter history of compression tend to experience more substantial recovery of function. Conversely, those with severe, long-standing deficits may only achieve stability or partial improvement.
Physical therapy and rehabilitation are necessary in the post-operative phase to maximize functional recovery, address muscle weakness, and improve gait and balance. While decompression stops the physical injury process, the nervous system requires time and guided activity to regain lost capabilities.
A long-term concern is the risk of developing adjacent segment disease, where accelerated wear and tear occurs at the spinal levels immediately next to a fused segment. There is also a possibility of recurrence if re-stenosis occurs at the operated site or new compression develops elsewhere. However, for most individuals, timely surgery successfully interrupts the progressive course of Cervical Myelopathy, leading to a stable functional outcome.