Receiving a diagnostic report mentioning “narrowing of C5 and C6” can be concerning. This phrase describes a specific anatomical change in the cervical spine (neck). This explanation defines what this finding means, why it occurs, and how it relates to overall health. Narrowing is common, especially with age, but requires careful interpretation by a healthcare provider to determine if it is causing symptoms.
The C5-C6 Segment and Cervical Anatomy
The cervical spine is the uppermost section of the backbone, consisting of seven bones, or vertebrae, labeled C1 through C7. The C5-C6 segment refers to the junction between the fifth (C5) and sixth (C6) vertebrae. Located toward the lower part of the neck, just above the shoulders, this region bears significant load and stress from the weight of the head.
The cervical spine supports the head, which weighs an average of 10 to 13 pounds, while allowing for extensive movement. A single vertebral segment, like C5-C6, includes the two bony vertebrae and an intervertebral disc positioned between them. This disc acts as a shock absorber, consisting of a tough outer ring and a soft, gel-like interior.
The segment also features openings on either side, called neural foramina, through which spinal nerves exit the spinal canal. The C6 nerve root, which controls sensation and movement in specific parts of the arm, exits the spine at the C5-C6 level. The spinal cord runs through the central, hollow space formed by the stacked vertebrae, known as the spinal canal.
Causes and Medical Definition of Narrowing
“Narrowing” is a general descriptor for spinal stenosis, a structural reduction in the space available for the spinal cord or nerve roots. This reduction can occur in the central spinal canal (central stenosis) or the neural foramina (foraminal stenosis). Both types of narrowing at the C5-C6 level are most frequently caused by age-related degenerative changes, often beginning after age 50.
A primary cause is the gradual drying out and flattening of the intervertebral disc, known as degenerative disc disease. As the disc loses water content and height, the space between the vertebrae decreases. This often causes the disc to bulge or herniate outward into the spinal canal or the neural foramen, encroaching on the space needed by neural structures.
Another factor contributing to narrowing is the formation of bone spurs, or osteophytes, along the edges of the vertebrae and facet joints. These growths are the body’s response to instability and wear, but they directly reduce the diameter of the spinal canal or the foramen. Ligaments that stabilize the spine can also thicken and become less flexible, further diminishing the available space for the spinal cord and nerve roots.
How Narrowing Impacts Nerves and Function
Narrowing transitions from a structural problem to a functional one when it compresses neural tissues. Compression of the spinal cord is termed cervical myelopathy, while pressure on the exiting C6 nerve root is known as cervical radiculopathy.
If the central canal is significantly narrowed, causing myelopathy, symptoms affect both the upper and lower extremities. This may manifest as difficulty with fine motor skills in the hands, such as buttoning a shirt or handling coins, or as balance and coordination problems leading to an unsteady gait. Myelopathy symptoms also include weakness, numbness, or tingling in a non-specific, bilateral pattern, often extending down the limbs.
When narrowing compresses the C6 nerve root, resulting in radiculopathy, symptoms follow a specific pathway. The C6 nerve root provides sensation to the thumb side of the forearm and hand, so compression often causes pain, numbness, or tingling in this dermatomal distribution. The C6 nerve root also controls the muscles for wrist extension and biceps function, making weakness in these muscle groups a common finding.
Treatment Pathways and Recovery
Management of C5-C6 narrowing typically begins with a conservative, non-surgical approach, especially if symptoms are mild or intermittent. Initial treatment involves physical therapy, focusing on strengthening neck and shoulder muscles to improve stability and posture. Therapists also use gentle stretching and range-of-motion exercises to reduce stiffness and improve flexibility in the neck.
Medications are a common component of early treatment, including non-steroidal anti-inflammatory drugs (NSAIDs) to manage pain and reduce inflammation in the affected tissues. For more focused relief, an intermediate step involves therapeutic injections, such as epidural steroid injections. These injections deliver anti-inflammatory medication directly to the area of the compressed nerve root, often providing substantial symptom relief.
If conservative treatments fail, or if there is evidence of progressive neurological deficits like worsening weakness or gait instability, surgical intervention may be considered. Common surgical procedures include anterior cervical discectomy and fusion (ACDF), where the damaged disc is removed and the vertebrae are fused. Another option is a foraminotomy, which enlarges the nerve root exit hole. Consulting with a specialist, such as a neurologist or an orthopedic spine surgeon, is necessary to determine the most appropriate and individualized treatment plan.