What Are the Causes of Forearm Pain?

Nerve root type cervical spondylosis is severe paroxysmal pain, which is distributed along the nerve root to the outside of the forearm and finger-like pain.

Electric shock pain on the outside of the forearm and fingers

Nerve root type cervical spondylosis is severe paroxysmal pain, which is distributed along the nerve root to the outside of the forearm and finger-like pain.

Affected area: Limbs
Related diseases: Omentitis, cervical spondylosis, osteoproliferative nerve root, cervical spondylosis, electric shock, traumatic arthritis, edema

Affiliated Department: General surgery
Related symptoms: Brachial plexus involvement of the hanging wrist, hypersensitivity, sensory disturbance, muscle atrophy

(I) Causes of Onset

Protrusion or prolapse of the nucleus pulposus, osteoproliferative or traumatic arthritis of the posterior facet joint, spur formation of the hook joint, and loosening of three adjacent joints (intervertebral joint, hook joint, and posterior facet joint) And displacement can cause stimulation and compression on the spinal nerve root. In addition, narrowing of the root canal, adhesive arachnoiditis at the root sleeve, and inflammation and tumors in the surrounding area can cause similar symptoms to this disease.

(Two) pathogenesis

Because this type has many onset factors and the pathological changes are more complicated, the location and degree of optic spinal nerve root involvement are different, and their symptoms and clinical signs are different. If the roots were previously compressed, the changes in muscle strength (including reduced muscle tone and muscle atrophy, etc.) are more obvious; in the future, if the roots are compressed, the symptoms of sensory disturbance are more severe. However, the two are mostly coexisting in the clinic. This is mainly because in the narrow root canal, various tissues are densely packed together, and it is difficult for everyone to shrink. Therefore, when the anterior side of the spinal nerve root is compressed, a compression phenomenon also occurs at the corresponding rear of the root canal. The mechanism of its occurrence is not only due to the hedging action of the force, but also due to the congestion and congestion of local blood vessels under pressure, which affects each other. Therefore, the majority of both sensory and motor dysfunction occur simultaneously. But because the sensory nerve fibers are more sensitive, the symptoms of paresthesia appear earlier.

This type of cervical spondylosis causes three clinical symptoms:

First, various pressure substances directly cause compression, traction, and local secondary reactive edema of the spinal nerve root, which presents as root symptoms;

The second is to show neck symptoms through the sinus vertebra nerve terminal branch on the dural sac wall at the root sleeve;

Third, the internal and external cervical imbalances are caused on the basis of the former two, causing local ligaments, muscles, and joint capsules of the vertebral ganglion to be implicated and produce symptoms (such as the affected vertebral ganglion and the interdependent cervical long muscle and anterior oblique muscle. And sternocleidomastoid muscle are involved in a part of the entire pathological process.

1. Neck, shoulder and upper limb pain, numbness. The cervical intervertebral disc protrudes laterally and posteriorly, the articulation of the hook vertebrae proliferates and enlarges, stimulating and compressing the cervical nerve roots, causing pain and numbness at the back of the neck, shoulders, back and upper limbs. The lighter ones only show faint pain, numbness, and soreness; the severe ones are Paroxysmal severe pain, distributed along the nerve roots to the forearm and fingers, accompanied by electric-like tingling sensation. Symptoms worse when coughing, defecation, and exertion. At the same time, there are often symptoms of lower limb muscle strength and inflexible finger movements.

2. Neck muscle tension was found during examination, and the flexion, extension, and abduction of the shoulder joint on the ipsilateral side were restricted to varying degrees, and there was tenderness in the cervical spinous process, paravertebral, supraganglia, and shoulder and spleen areas. Upper limb pull test was positive: the operator stood on the affected side, holding the affected side's neck with one hand, and holding the affected wrist with the other, pulling in the opposite direction. Radiation pain occurs because the brachial plexus nerve is stretched, which stimulates the compressed nerve roots. Positive indentation test: The patient took a sitting position, tilted his head back to the affected side, and the surgeon pressed the top of his head with the palm of his hand. At this time, neck pain occurred and he radiated to the affected hand. There may be mild muscle atrophy in the upper limbs, reduced grip strength, decreased forearm and hand sensation, weakened biceps reflex, and periosteum reflex.

3. X-ray plain film showed that the physiological curve of cervical vertebra disappeared, the cervical vertebra became straight, the intervertebral space became narrow, bone hyperplasia of the anterior and posterior margins of the vertebral body, hyperplasia of the articulated vertebrae, and the corresponding intervertebral foramen became smaller and deformed. CT or magnetic resonance (MRI) showed degeneration and protrusion of the disc, spinal stenosis, and compression of the dural sac and nerve roots.

There are 8 pairs of cervical spine nerves, and they dominate different parts. Therefore, when they are affected, the distribution and difference of symptoms are different depending on the affected parts. In clinical practice, cervical spine nerve roots involving 5 to 8 are more involved, so this is the focus to identify confusing injuries.

Ulnar neuritis

(1) Overview: The ulnar nerve is composed of the cervical 7,8 and thoracic 1 spinal nerves. The disease is more common in older people and old elbow injuries, and the incidence of elbow deformity is higher. This disease is easily confused with those with cervical 8 spinal nerve involvement (Figure 4).

(2) Identification points:

Posterior elbow ulnar nerve tenderness: The ulnar nerve sulcus located on the medial side of the elbow joint has more obvious tenderness, and can touch the cord-like degenerated ulnar nerve.

Sensory disorders: The sensory disorder distribution area is smaller than that of the 8th cervical nerve, and the ulnar side of the forearm is not affected.

Influence of the internal muscles of the hand: When the ulnar nerve is severely affected, it is often a claw-shaped hand (Figure 5); the Tinel sign of the wrist ulnar nerve tube is mostly positive (Figure 6). Mainly due to the involvement of the interosseous muscles, which causes the metacarpophalangeal joints to overextend and flexion of the interphalangeal joints, especially the ring and little fingers.

Imaging changes: refer to plain radiographs (neck X-rays of patients with ulnar neuritis are mostly negative, but X-rays of the elbow joint, especially those with deformities may have positive findings), medical history and past History, etc.

2. Median nerve damage

(1) Overview: The median nerve is composed of the cervical 7 and thoracic 1 spinal nerves. The damage is mostly caused by trauma or compression of the fibrous duct. The former factor can be diagnosed at the time of the trauma. It is easy to be confused with the 7th cervical spine nerve root compression, and it needs to be carefully identified.

(2) Identification points:

Sensory disorders: As shown in Figure 7, the sensory disorders are mainly distributed in the dorsal fingertips and the thumb, palm, and palm, but the forearms are not affected.

Muscle strength changes: The strength of the hand muscles weakened, and the appearance was ape hand deformities, which were mainly caused by atrophy of the great intermuscular muscles (Figure 8).

Autonomic Symptoms: Because the median nerve is mixed with a large number of sympathetic nerve fibers, the blood vessels and hair follicles of the hands are in abnormal states, such as flushing, sweating, and the pain is often burning.

Reflex: No effect; but when the cervical 7 spinal nerve is involved, the triceps reflex can weaken or disappear.

3. Radial nerve injury

(1) Overview: The radial nervous system is composed of cervical 5-7 and thoracic 1 spinal nerves. It is located in the radial sulcus of the humeral shaft in the upper arm, runs close to the bone surface, and is easily affected by humeral shaft fractures. Radial nerve injury caused by trauma is easy to identify. If it is caused by factors such as fibrous adhesion and local entrapment, it needs to be distinguished from the 6th cervical spine nerve involvement.

(2) Identification points

Vertical wrist sign: a symptom unique to radial nerve damage, mainly due to the loss of control of the extensors of the wrist and extensor muscles. In patients with high radial nerve involvement, elbow extension is also affected.

sensory disorders: as shown in Figure 9. It is different from the involvement of the 6th cervical nerve in that the sensory disturbance area is mainly the dorsal side (thumb, forefinger, middle finger) and the forearm dorsal side except the finger end, and there should be no obstacles on the palm and thumb side.

Change in reflection: no significant effect. In the case of cervical 6 spinal nerves, the biceps and triceps reflexes weakened or disappeared (early hyperthyroidism).

Others: refer to the medical history, local examination and X-ray plain film.

4. Thoracic outlet syndrome

(1) Overview: Thoracic outlet syndrome (TOS), also known as thoracic outlet stenosis, is more common clinically, and can be directly compressed under the brachial plexus, or due to anterior oblique muscle contracture and inflammatory stimulation. The anterior branch of the cervical spine nerve is affected, which causes symptoms of the upper limbs, mainly sensory disorders, and can cause hand muscle atrophy and weakened muscles. The disease mainly includes the following three types, namely, anterior oblique muscle syndrome, cervical rib (or 7th cervical vertebra process), and costal lock syndrome. Although the three are different, they all have similar characteristics and are distinguished from nerve root type cervical spondylosis.

(2) Identification points:

Brachial plexus involvement: mainly the lower trunk of the brachial plexus, which is often manifested as a sensory disorder extending from the ulnar side of the upper arm to the forearm and ulnar side of the hand, and the ulnar carpi flexor, superficial flexor and bone Intermuscular involvement (Figure 10).

Local signs of thoracic cavity exit: the upper clavicle fossa on the ipsilateral side is mostly full. When checking, you can touch the cord-like anterior scalene muscle or osseous cervical ribs. When you press with your thumb to the deep part (or let the patient inhale deeply) Exercise) can induce or exacerbate symptoms.

Adson sign: mostly positive. That is, let the patient sit with their heads tilted back slightly, hold their breath after taking a deep breath, and turn their heads to the affected side. The examiner rested on the patient's jaw with one hand, giving a little resistance. Touch the affected radial artery with the other hand. If the pulse weakens or disappears, it is positive. This is a special test for this disease.

Others: including imaging changes. In this disease, X-ray films are mostly positive, and CT or MRI examinations if necessary can help distinguish between the two. In addition, the neck pressure test of this disease is negative, and there is no tenderness and other signs in the spinous process and the cervical spine. Therefore, it is not difficult to distinguish the two.

5. Carpal tunnel syndrome

(1) Overview: Carpal tunnel syndrome is mainly caused by the compression of the median nerve through the carpal tunnel. It is also more common in clinical practice, especially in the middle, elderly, and wrist trauma patients.

(2) Identification points:

Middle wrist compression test: that is, the examiner presses the middle of the patient's wrist (palm side) with his or her middle finger, which is equivalent to the proximal end of the transverse ligament of the wrist. If the thumb, index finger, middle finger is numb or tingling, It is positive and has diagnostic significance (Figure 11).

Wrist extension test: The patient is allowed to extend the affected wrist joint to the dorsal side for 0.5 to 1 min. If there is numbness or tingling symptoms in the thumb, sign, middle finger, it is positive and diagnostic significance.

Closure test: 1 to 2 ml of 1% procaine is used to locally close the pain points on the wrist. If it is effective, it is positive.

Others: There are symptoms of sensory disturbances of the distal median nerve endings (numbness of the thumb, index finger, middle finger, hypersensitivity or tingling), no corresponding changes in the neck X-ray film, and cervical spondylosis of the nerve root type All tests are negative, if necessary, refer to the results of MRI examinations.

6. Periarthritis of shoulder and other shoulder diseases

(1) Periarthritis of the shoulder: It should be distinguished not only from cervical spondylosis but also from radiculopathy. In addition to the characteristics described in the previous section, the disease does not have the root symptoms of the spinal nerve, so it is easy to identify. However, it should be noted that some cases of cervical spondylosis may be clinically accompanied by inflammation of the shoulder joint. After treatment (such as traction or surgical treatment), the shoulder symptoms may disappear along with other symptoms of cervical spondylosis. This is mainly due to the involvement of the cervical spine nerves 5 to 7 through the axillary nerves to the shoulders.

(2) Other shoulder disorders: including shoulder impingement, rotator cuff disease, shoulder degeneration, and shoulder instability, etc., should be distinguished from nerve root type cervical spondylosis. Mainly based on clinical examination and imaging results, it is generally not difficult to identify. Individuals with difficult diagnosis can be judged by closed therapy.

7. Spinal and root canal tumors

All tumors invading the spinal nerve root and its surroundings, including tumors lateral to the dural sac, the root canal and its adjacent tissues (mainly bone tissues), can cause root pain. Among them, metastatic ones are more common. And it can affect the spinal nerve root and cervical plexus or brachial plexus at the same time, causing a variety of root or plexus symptoms. Therefore, in addition to routine inspections and palpation of the supraclavicular fossa and neck and shoulders, X-ray, CT and MRI examinations should be performed on the shoulder and neck as a center to prevent missed diagnosis or misdiagnosis.

8. In addition to the above injuries, attention should be paid to distinguishing from peripheral neuritis, syringomyelia, rheumatism, tennis elbow (external epicondylitis of humerus), biceps tendonitis, and angina pectoris.

(A) treatment

1. Non-surgical therapy Various targeted non-surgical therapies have obvious curative effects. Among them, continuous (or intermittent) traction of the head and neck, braking around the neck, and correction of poor posture are more important. Manual massage also has a certain effect, but it should be gentle. Avoid accidents caused by rough operation. It is not suitable for massage and push.

2. Surgery The following conditions can be considered surgery:

(1) It is ineffective for more than 3 months after formal non-surgical therapy, and the clinical manifestations, imaging findings and neurological location are consistent.

(2) Progressive muscle atrophy and severe pain.

(3) Although non-surgical therapy is effective, it affects work, study and life due to recurrent symptoms.

The anterior cervical decompression is appropriate, which not only has good curative effect, but also has little effect on the stability of the cervical spine. For those with vertebral instability or root canal stenosis, intervertebral interfacial internal fixation can also be used at the same time to spread and fixate the vertebrae. The posterior neck approach to achieve decompression by incision of small joints is effective, but it is easy to cause cervical vertebra angulation deformities after surgery, which has gradually been abandoned. Laminectomy can also be used to remove or scrape the bony compressive material from the rear side of the vertebral body, but this method is difficult and easy to be injured by accident.

(B) the prognosis

1. Due to simple cervical nucleus pulposus, the prognosis is mostly good, and few patients have recurrence after cure.

2. The prolapse of nucleus pulposus has easily formed residual symptoms.

3. For prognosis caused by hook joint hyperplasia, early and timely treatment is more satisfactory. If the course of the disease is long and the subarachnoid space adhesion has formed at the root canal, the effect is likely to be unsatisfactory due to the delay of symptoms.

4. Radical pain due to extensive bone hyperplasia is not only complicated to treat, but also has a poor prognosis.

What Are the Causes of Forearm Pain?

Electric shock pain on the outside of the forearm and fingers

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