Cervical spondylotic radiculopathy (CSR) is a clearly diagnosed and clinically common type of cervical spondylosis among all types of cervical spondylosis. It is a cervical spine disc degenerative changes and its secondary pathological changes stimulate and compress the spinal nerve roots, and clinical manifestations such as radiating pain and numbness in the upper limbs of the corresponding segment appear.
1.Symptoms and signs.
The symptom onset process can be acute or chronic, with acute onset occurring mostly at the age of 30 to 40 years old, often a few days after neck trauma or with a previous history of neck trauma. The symptoms are mainly painful, manifested as severe neck pain and limited neck movement, neck pain radiates to the shoulder, arm, forearm and fingers, and there may be upper limb weakness and finger numbness. When the pain is severe, the patient may not even be able to sleep. The course of the disease is chronic, and most of the patients have developed from acute attacks, and a significant number of patients have multiple nerve root involvement. The age of the patient is higher than that of the patient with acute attack, and it is manifested by dull pain in the neck and radiating pain in the upper limbs, and there may be numbness in the scapula. Common triggers include exertion, cold, and lifting heavy objects.
The symptoms may be unilateral or bilateral, usually involving a single nerve root, or two or more nerve roots due to a multisegmental lesion. Cervical spine lesions are mainly seen below the cervical 4-5 segments, with cervical 5, cervical 6 and cervical 7 nerve root involvement being the most common.
Neck pain is the most common clinical symptom of cervical spine disorders, but it is not unique to neurogenic cervical spondylosis. In neurogenic cervical spondylosis, the pain may radiate to the shoulder and medial scapula, and may be accompanied by restricted cervical movement, paravertebral muscle spasm and paravertebral pressure pain, and is often accompanied by headache. The cause of the pain is still unclear and may be related to stimulation of nonspecific sensory nerves in the fibrous rings and ligaments of the cervical discs, paravertebral muscle spasm or osteoarthritis of the small joints, or autoimmune and inflammatory reactions caused by the discs.
Radicular pain is the most important clinical manifestation of neurogenic cervical spondylosis, and sometimes it is even the only clinical manifestation. Since there is mostly single nerve root involvement, pain is often confined to a specific area of the neck, chest or upper extremity. Rotation, lateral flexion or posterior extension of the cervical spine can induce or exacerbate radicular pain.
Commonly used tests are.
(1) Spurling test: also known as intervertebral foraminal squeeze test, the patient’s head is flexed laterally to the affected side while tilting back, and the examiner presses downward with both hands from the top of the patient’s head to induce or intensify pain in the affected shoulder and upper extremity as a positive Spurling sign.
(2) Jackson’s test: The examiner supports the patient’s head with one hand and bends it to the healthy side, while pressing the healthy shoulder with the other hand downward, which induces or aggravates the pain of the affected shoulder and upper limb.
(3) Upper limb extension test: also known as brachial plexus pull test, the patient’s head is flexed to the affected side and tilted back slightly, while maintaining the upper limb in the extended elbow and wrist position, and external rotation of the shoulder joint induces or aggravates the pain and numbness of the affected shoulder and upper limb.
According to Henderson and Hennessy, in a group of 846 cases of neurogenic cervical spondylosis, the triceps, biceps, deltoid and intrinsic hand muscles were involved in 37%, 28%, 1.9% and 0.6% of cases, respectively, and 68% of patients had varying degrees of muscle weakness. When the degree of hypotonia is mild, the effect on upper limb movement is slight, and when the disease progresses slowly, the function of the damaged muscles can still be compensated by other muscles, which is often not easily detected by the patient, so a systematic and detailed physical examination is important for diagnosis.
The tendon reflex can sometimes be weakened, and the comparison between the two sides should be noted during physical examination.
2.Imaging examination.
2.1 X-ray plain film: orthopantomogram shows the formation of articular spurs in the hook vertebral joint (Luschka joint). Lateral radiographs show narrowing of the vertebral space, formation of spurs on the anterior and posterior edges of the vertebral body, and the physiological anterior convexity of the cervical spine may be reduced or disappeared. The osteoarthritis of the hook joint and synovial joint is more clearly demonstrated in the oblique view. These changes may become more pronounced with increasing age, with cervical 4-5 being the most common.
The degree of stability of the cervical spine can be determined on the basis of lateral cervical flexion/extension films. The judgment is based on two main factors: (1) the horizontal displacement of vertebral body is greater than 3.5mm; (2) the angle difference between two adjacent vertebral spaces is greater than 11°.
2.2 Myelography: Filling defects of the nerve roots of the lesioned segment can be shown on orthogonal, lateral and oblique films. The filling defect is biased to the affected side in the orthopantomogram, while it is more obvious in the oblique one. The filling defect on the lateral view is anterior and consistent with the level of the disc, but to a lesser extent. It generally does not show the intraforaminal compression very well.
2.3 Intervertebral discography: The disc is irregularly imaged after contrast injection, and the contrast agent diffuses in all directions, and may even leak into the Luschka joint or even the spinal canal. When contrast is injected, attention should be paid to whether the patient’s pain response is the same as the clinical symptoms, and comparison with adjacent joints is required. It is generally used to determine discogenic pain.
2.4 CT scan: The herniated disc tissue shows an increased density shadow, and CT shows the bony structures of the intervertebral foramen particularly well. Unfortunately, the difference in density between the nerve roots and intervertebral discs and the ligamentum flavum seems to be less pronounced than in the lumbar spine, and CT myelography can make up for this deficiency.
2.5 MRI: The signal of the cervical disc is generally stronger than that of the lumbar spine, and the signal of the central nucleus pulposus is significantly stronger than that of the surrounding annulus fibrosus. The spinal cord tissue signal is moderately strong, and its surrounding cerebrospinal fluid and dural sac signal is low. On T2-weighted images, the signal of the intervertebral disc is significantly stronger than on T1-weighted images, and the signal of the degenerated disc is significantly lower.MRI can show the compression of nerve roots by the herniated cervical disc tissue more accurately, with axial images being more diagnostic. However, it is difficult to differentiate between a protruding disc and a hyperplastic Luschka joint on T1-weighted images.
3. Diagnostic points of neurogenic cervical spondylosis.
① neck pain with upper limb radiating pain; ② weakened sensation in the distribution area of skin segments of compressed nerve roots, abnormal tendon reflexes, muscle atrophy and muscle strength loss; ③ positive brachial plexus nerve pull test or intervertebral foramen squeeze test; ④ cervical spine X-ray shows vertebral hyperplasia, obvious hyperplasia of the hook vertebral joint and small intervertebral foramen; ⑤ MRI and CT show disc protrusion, posterior vertebral spur and narrowing of the nerve root canal and enlargement of spinal nerve roots.
In addition, there can be hypoesthesia or hypersensitivity, muscle atrophy or weakened tendon reflexes in different parts of their respective areas. Weakness of upper limb muscles is a symptom of motor nerve damage, which is manifested by the patient’s difficulty in holding objects, and some patients tend to fall off when holding objects. The skeletal muscles of the limbs are jointly innervated by more than two nerves, and damage to individual nerves may manifest as mild muscle weakness, while involvement of major nerve roots may result in significant motor dysfunction.
Protrusion of the cervical intervertebral disc to the lateral posterior after degeneration or the development of hyperplastic bone spurs in the hook vertebral joint may stimulate compression of the nerve roots of the corresponding segment and the corresponding clinical manifestations may occur. Different segments of cervical spine lesions can stimulate or compress different nerve roots, resulting in different manifestations, and their respective specific clinical manifestations are as follows.
Lesions above the 3-4 interspace of the cervical spine can stimulate or compress the nerve roots of cervical 3 or cervical 4, and the patient often feels neck pain, strings to the head and occipital area, and there may be pressure pain near the Fengchi point and numbness in the skin of the occipital area. However, it is generally less common for cervical spondylosis to occur in segments above the 3-4 interval of the cervical spine with degeneration.
Cervical spine 4-5 gap lesions can stimulate or compress the cervical 5 nerve root, and patients often feel pain via the top of the shoulder, the upper part of the inner edge of the scapula, the shoulder, radiating to the outer part of the upper arm, and rarely to the forearm. When the doctor examines the patient, he may find that there may be pain hypersensitivity or hyperalgesia in the shoulder and the lateral upper arm, and the muscle strength of the deltoid muscle in the upper arm abduction and elevation is reduced. In severe cases, muscle atrophy of the deltoid, trapezius and supraspinatus muscles in the shoulder may be found, and under direct vision, the above muscles may be found to lose their normal plump shape and collapse after atrophy.
Lesions in the cervical spine 5-6 interspace can irritate or compress the cervical 6 nerve roots. In addition to pain and numbness in the neck, inner edge of the shoulder lunate, shoulder, anterior thorax and radial side of forearm (thumb side of forearm), the patient can also radiate to the lateral side of upper arm, radial side of forearm (thumb side of forearm) and thumb and index finger. On examination, the physician may find hyperalgesia or hyperalgesia in the lateral upper arm, the radial side of the forearm (thumb side of the forearm), and the thumb and index finger; weak elbow flexion strength (biceps strength) and hyporeflexia of the biceps tendon reflexes. Weak or absent radial tendon reflexes may be found; in severe cases, atrophy of the biceps muscle (i.e., the muscle on the anterior side of the upper arm) may occur.
Cervical spine 6-7 interval lesions can irritate or compress the cervical 7 nerve root, and the patient feels pain radiating along the upper arm of the neck and shoulder to the dorsal side of the forearm, index finger and middle finger. On examination, the doctor may find that the patient has hyperalgesia or hyperalgesia in the index and middle fingers, reduced elbow extension strength, and reduced or absent triceps tendon reflexes; wrist extension and finger extension muscle strength may also be reduced at times.
Lesions in the cervical7 and thoracic1 interspace can irritate or compress the cervical8 nerve roots, and the patient has pain in the neck, shoulder, and the inner lower border of the scapula, and often radiates along the medial side of the upper arm and the ulnar side of the forearm (i.e., the medial or pinky side of the forearm) to the ring finger and little finger, with greater impairment of fine hand movement. During the examination, the doctor may find that the patient has hyperalgesia or hyperalgesia of the little finger and ring finger, and the power of flexion of the index finger, middle finger, ring finger and little finger, as well as the power to separate and join together, is often reduced, and in severe cases, hand muscle atrophy is evident, and there is generally no change in tendon reflexes.
4.Clinical stages.
① Acute stage: also known as inflammatory edema stage. The main clinical manifestations are: pain in the neck and shoulder, restricted movement of the cervical spine, the pain in the neck, shoulder and arm can be aggravated by slight activity, and it is difficult to sit and lie down when the pain is severe, and the affected limb is dragged by the healthy limb passively, affecting sleep.
② Chronic phase: also called ischemic phase. The main clinical manifestations are: neck stiffness, soreness and dullness of the back of the neck and shoulder, restricted movement of the cervical spine, and painful string numbness of the affected limb, which can be tolerated.
③ Recovery period: the symptoms of numbness and pain in the neck, shoulder and upper limb disappear, but the symptoms of soreness and dullness in the back of the neck, shoulder and upper limb still exist, and the symptoms are aggravated by cold or exertion.