Anatomical and Physiological Overview
The cervical spine consists of seven cervical vertebrae and six intervertebral discs. The first cervical vertebra, also known as the atlas, is composed of an anterior arch, a posterior arch, and two lateral masses. The second cervical vertebra, or axis, has a dens that projects upward from its vertebral body, forming the atlanto-odontoid joint with the anterior arch of the atlas. The transverse processes of the first to seventh cervical vertebrae feature transverse foramina, through which the vertebral arteries pass from the transverse foramen of C6 to C1 and into the cranial base.
Characteristics of cervical intervertebral connections:
The vertebrae are connected via five joints at each segment: the intervertebral disc, two uncovertebral joints, and two facet joints.
The posterior longitudinal ligament in the cervical region is relatively wide, with a thick and firm central portion. Degeneration, hypertrophy, and calcification of the posterior longitudinal ligament in the cervical region are important causes of spinal canal stenosis and spinal cord compression.
The supraspinous ligament in the cervical spine is particularly strong and forms the nuchal ligament, which resists cervical flexion. Degeneration and calcification of the nuchal ligament are also potential causes of neck pain.
The cervical spine has the greatest range of motion in the entire vertebral column. The primary site of flexion and extension of the head is the atlanto-occipital joint, while rotation occurs primarily at the atlantoaxial joint. Most cervical flexion and extension occur in the lower cervical spine. When the mobility of any spinal segment is restricted, the adjacent cervical segments bear increased stress on their joints, intervertebral discs, and ligaments, leading to their degeneration.
The cervical region has a complex neurological structure:
Among the spinal cord's three physiological enlargements, the cervical enlargement in the lower cervical region is the most prominent, making the spinal canal relatively narrow and its internal nerve structures more susceptible to compression.
The cervical plexus is formed by the anterior rami of C1–C4 nerves and is responsible for innervating the neck muscles, diaphragm, and the sensory regions of the neck, occipital area, and face. The posterior rami of C1–C4 nerves form the posterior cervical plexus. Irritation of the greater occipital nerve (arising from the posterior ramus of C2) can cause pain in the suboccipital muscles and sensory abnormalities in the ipsilateral scalp.
The brachial plexus is formed by the anterior rami of C5–T1 spinal nerves and innervates the scapular, shoulder, thoracic, and upper limb muscles and skin.
The cervical spinal cord does not have preganglionic sympathetic fibers, which instead originate from the upper thoracic spinal cord. These fibers ascend and synapse to form the cervical sympathetic ganglia and chains. Postganglionic fibers from these structures join the cervical spinal nerves and, in some cases, the cranial nerves. As a result, the cervical sympathetic nerves have a wide range of functions, and their irritation can result in symptoms and signs involving multiple organs and systems.
Diseases that cause neck and shoulder pain are numerous, with cervical spondylosis and cervical myofibrositis being the most common. The causes and classifications of these conditions are broadly similar to those of low back and leg pain:
- Cervical spondylosis
- Cervical myofibrositis: This nonspecific, aseptic inflammatory condition results from various factors that cause microcirculatory disturbances, tissue exudation, edema, and fibrotic changes within the cervical fascia and muscles.
Etiology
Acute Trauma
Previous acute soft tissue injuries in the cervical region that were not promptly or properly treated may progress to chronic traumatic inflammation.
Chronic Strain
Prolonged maintenance of a single position or sustained load on the shoulders can lead to chronic strain.
Structural Abnormalities of the Cervical Spine
Abnormal curvature or instability of the cervical spine may result in prolonged muscle tension as the body attempts to maintain local or overall balance.
Environmental Factors
Weather can significantly influence this condition. Cold and damp conditions affect the nutrition and metabolism of the muscles and fascia.
Psychological Factors
Conditions such as depression, obsessive-compulsive disorder, and chronic anxiety may have an impact.
Other Factors
Certain viral infections or rheumatic diseases are associated with this condition.
Clinical Manifestations
The condition is primarily characterized by chronic pain in the neck, shoulders, and upper back. Symptoms worsen in the morning or after exposure to cold or changes in weather. Physical activity often alleviates the pain, though symptoms tend to recur. During acute episodes, there may be localized muscle spasms, neck stiffness, and restricted movement. Symptoms may become exacerbated by weather changes, cold and damp conditions, physical overexertion, or mental stress. The condition may be underdiagnosed or subjected to excessive diagnostics and treatments.
On physical examination, noticeable tender points, painful nodules (fascial fat herniation), and cord-like structures can often be palpated in the painful regions. Localized muscle spasms may also be detected. In severe cases, cervical spine motion is limited, though there are no indications of nerve damage. Diagnostic imaging such as X-rays or infrared thermography is generally sufficient for a preliminary diagnosis.
Diagnosis
Diagnosis is often made based on a combination of medical history, symptoms, and physical signs. Patients typically have a history of living or working in cold, damp environments or a history of chronic strain. Most cases present the typical symptoms and signs mentioned earlier. X-ray imaging may reveal varying degrees of degenerative changes, although it may also show no positive findings. Complex tests such as CT or MRI are generally unnecessary for this condition. In some patients, an elevated erythrocyte sedimentation rate (ESR) and a positive anti-streptolysin O (ASO) test may suggest that the etiology is related to rheumatic activity.
Differential Diagnosis
This condition needs to be differentiated from cervical degenerative pain, cervical disc herniation, and frozen shoulder. It often coexists with degenerative diseases of the cervical spine, making differentiation challenging. However, since the treatment principles for early degenerative conditions are similar, observations during treatment can aid in determining the underlying diagnosis.
Treatment
The condition is primarily managed through non-surgical treatment, with an emphasis on addressing the underlying cause and combining prevention with intervention. Non-surgical approaches may include local physiotherapy, massage, and oral administration of nonsteroidal anti-inflammatory drugs (NSAIDs). For patients with significant localized pain, corticosteroid injection therapy may be utilized, although addressing causative factors such as maintaining warmth and correcting poor posture is crucial to prevent recurrence.
For patients with distinct tender points or peripheral nerve compression, localized point or patch soft tissue release procedures may be performed. This involves surgical decompression of the adhesions and fibrosis affecting the fascia, as well as the vascular and nerve endings.