Symptoms of the defeat of the cervical plexus and its branches

For the precise and differentiated control of the movements of the head, numerous neck muscles require separate innervation. Therefore, a significant part of the fibers from the spinal roots and nerves, without interlacing, go directly to the muscles or the skin of the neck and head.

The first cervical nerve (n. Cervicalis primus) emerges from the spinal canal through the gap between the occipital bone and the atlas along the sulcus a. Vertebralis and is divided into the anterior and posterior branches.

The anterior branch of C. Extends to the anterolateral surface of the spine between the lateral rectus muscle of the head and the anterior straight muscle of the head and innervates them. The contraction of the lateral rectus muscle of the head on one side promotes the inclination of the head in the same direction, with bilateral contraction - forward. The forward rectus muscle of the head tilts the head in its direction.

The posterior branch of CI is called the suboccipital nerve (n. Suboccipitalis) and supplies the large posterior and minor posterior rectus muscles of the head, the upper and lower oblique muscles of the head. With one-sided cutting all these muscles tilt the head back and to the side, with the bilateral - back.

Isolated lesion of the 1st cervical spinal nerve is rare and is observed in pathological conditions in the upper cervical vertebrae. When the fibers of this nerve become irritated, convulsive contractions of the lower oblique muscle of the head arise. With a one-sided clonic cramp of this muscle, the head turns rhythmically to the affected side; at its tonic convulsion the head turns slowly and this turn is longer. In the case of bilateral convulsions, the head turns to one or the other side - a rotational cramp (tic rotatore).

The second cervical nerve (n. Cervicalis secundus), leaving the intervertebral opening CII, is divided into the anterior and posterior branches. The anterior branch participates in the formation of the cervical plexus. The posterior branch extends posteriorly between the atlas and the axial vertebrae, skirts the lower edge of the lower oblique muscle of the head and divides into three main branches: the ascending, descending and large occipital nerve (n. Occipitalis major). Two branches innervate part of the lower oblique muscle of the head and the rib muscle. With a one-sided contraction of these muscles, the head rotates in the appropriate direction, with a bilateral one - the head bends backwards with the extension of the neck.

The test for determining the strength of the posterior group of the muscles of the head: the patient is offered to tilt his head back, the researcher is resisting this movement.

The large occipital nerve emerges from beneath the lower edge of the lower oblique muscle of the head and is arched upward. Together with the occipital artery, this nerve perforates the tendon of the trapezius muscle near the external occipital protrusion, penetrates the skin and innervates the skin of the occipital and parietal areas. With the defeat of this nerve (influenza, spondylitis, trauma, tumors, reflex spasm of the lower oblique muscle of the head) there is a sharp soreness in the nape. The pain is paroxysmal and intensified with sudden movements of the head. Patients keep their head still, slightly tilting it back or to one side. With neuralgia of the great occipital nerve, the painful point is localized on the inner third of the line connecting the mastoid process and the external occipital protrusion (the exit point of this nerve). Sometimes there is hypo- or hyperesthesia in the nape of the neck and hair loss.

Neck weave (plexus cervicalis). It is formed by the anterior branches of CI - CIV spinal nerves and is located laterally from the transverse processes on the front surface of the middle staircase and the muscle that lifts the scapula; front covered with a sternocleidomastoid muscle. From the plexus depart sensitive, motor and mixed nerves. In the course of these nerves there are areas of perforation through the fascia or the muscle itself, where conditions for compression ischemic lesions of the nerve trunk can be created.

The small occipital nerve (n. Occipitalis minor) departs from the cervical spine and consists of fibers of the spinal nerves CI-CIII. It passes through the fascial vagina of the upper oblique muscle of the head and branched out into the skin of the outer part of the occipital region. The lesion clinic is presented with complaints of paresthesia (numbness, tingling, crawling) in the outer occipital region. They occur at night and after sleep. Hypesesia is detected in the zone of branching of the small occipital nerve and painfulness at the palpation of the point at the posterior margin of the sternocleidomastoid muscle in the place of its attachment to the mastoid process.

Similar sensations can occur in the temporo-occipital region, the auricle and the external auditory canal. In such cases, differential diagnosis is performed with a lesion of the large ear nerve, which consists of fibers of the spinal nerve III. If the paresthesia and pain are localized along the outer surface of the neck from the chin to the clavicle, one can think of the defeat of the transverse nerve of the neck (n. Transversus colli) - the branch CII-CIII of the spinal nerves.

From the anterior branches of the CIII and CIV spinal nerves are formed supraclavicular nerves (nn. Supraclavicularis). They exit from the posterior edge of the sternocleidomastoid muscle and are sent obliquely downward into the supraclavicular fossa. Here they are divided into three groups:

• the anterior supraclavicular nerves branch out in the skin above the sternal part of the clavicle;
• middle supraclavicular nerves cross the clavicle and supply the skin from the region of the breast to the IV rib;
• posterior supraclavicular nerves run along the outer edge of the trapezius muscle and terminate in the skin of the upper oblate region above the deltoid muscle.

The defeat of these nerves is accompanied by pain in the neck, intensifying when the head is tilted to the sides. With intense pain, tonic tension of the occipital muscles is possible, which leads to the forced position of the head (tilted to the side and fixedly fixed). In such cases it is necessary to differentiate from a meningeal symptom (stiff neck muscles). There are disorders of surface sensitivity (hyperesthesia, hypo- or anesthesia). Pain points are detected with pressure at the posterior margin of the sternocleidomastoid muscle.

Muscular branches of the cervical plexus innervate: interdigitus muscles, which, with one-sided contraction, participate in the inclination of the neck to the side (innervated by segment CI-CII); the long muscle of the head - tilts the cervical spine and head forward (innervated by segment CI-CII); lower hyoid muscles (mm. Omohyoideus, stenohyoideus, sternothyroideus), which pull the hyoid bone at the act of swallowing (innervated by segment CI-CII); sternocleidomastoid muscle - with a one-sided contraction it tilts the head toward the contraction, and the face thus turns in the opposite direction; with bilateral reduction - the head is thrown back (innervated by segment CII-CIII and n. Accessorius).

Tests to determine the strength of the sternocleidomastoid muscle:

1. the subject is offered to tilt his head to the side, and his face to turn in the direction opposite to the inclination of the head; the examiner is resisting this movement;
2. offer to tilt your head back; The examiner is resisting this movement and palpating the contracted muscle.

The muscular branches of the cervical plexus also innervate the trapezius muscle, which brings the scapula closer to the spine, if the whole muscle contracts, lifts the scapula - when the upper tufts contract, lowers the scapula - when the lower portion is cut (innervated by segment CII-CIV, n. Accessorius).

The test for determining the strength of the upper part of the trapezius muscle: the subject is offered to shrug his shoulders; the examiner is resisting this movement. When cutting the top of the m. Trapezii scapula rises up and the lower corner of it turns outwards. With paralysis of this muscle, the shoulder falls, the lower angle of the scapula turns into the medial side.

The test for determining the strength of the middle part of the trapezius muscle: the subject is offered to move the shoulder back, the examiner is resisting this movement and palpating the contracted part of the muscle. In norm under the action of the middle part of m. Trapezii scapula is brought to the spinal column; when paralysis, the scapula is removed and slightly lagged behind the thorax.

The test for determining the sip of the lower part of the trapezius muscle: the subject is offered to move the raised upper limb back, the examiner is resisting this movement and palpating the shortened lower part of the muscle. Normally, the blade is somewhat lowered and approaches the vertebral column. With paralysis of this muscle, the scapula rises somewhat and separates from the spinal column.

The diaphragmatic nerve (n .phrenicus), a mixed nerve of the cervical plexus, consists of fibers of CIII-CV spinal nerves, as well as sympathetic fibers from the middle and lower cervical nodes of the sympathetic trunk. The nerve is located down the front staircase and penetrates into the thoracic cavity, passing between the subclavian artery and the vein. The left diaphragmatic nerve runs along the front surface of the aortic arch, in front of the root of the left lung and along the left lateral surface of the pericardium to the diaphragm. Right - is located in front of the root of the right lung and passes along the lateral surface of the pericardium to the diaphragm. The motor fibers of the nerve supply a diaphragm, sensitive - innervate the pleura, the pericardium, the liver and its ligaments, in part the peritoneum. This nerve is anastomosing with the celiac plexus and the sympathetic plexus of the diaphragm.

With a reduction, the dome of the diaphragm is flattened, which increases the volume of the chest and promotes the act of inspiration.

The test for determining the action of the diaphragm: the subject in the supine position is offered to take a deep breath, the examiner palpates the strained wall of the abdomen. With unilateral paralysis of the diaphragm, the tension of the corresponding half of the abdominal wall is weakened.

Paralysis of the diaphragm leads to a restriction of the mobility of the lungs and a certain breach of breathing. When you inhale, the diaphragm passively lifts the muscles of the anterior abdominal wall. The type of respiratory movements becomes paradoxical: when the inhalation the epigastric region falls, and when exhaled - it protrudes (in norm - on the contrary); difficult coughing movements. The mobility of the diaphragm is well assessed by fluoroscopic examination.

When the diaphragmatic nerve irritates, a diaphragm cramps arises, which is manifested by hiccups, pains that spread to the area of the shoulder, shoulder, neck and chest.

The diaphragmatic nerve is affected in infectious diseases (diphtheria, scarlet fever, influenza), intoxications, traumas, metastases of a malignant tumor into the cervical vertebrae, etc.

Simultaneous defeat of the entire cervical plexus is rare (with infection, intoxication, trauma, tumors). With a bilateral paralysis of the neck muscles, the head leans forward, it can not lift the patient. The irritation of the trunks of the cervical plexus leads to a spasm, which extends to the oblique muscles of the head, the waist muscle of the neck and the diaphragm. With a tonic cramp of the neck muscle, the head is tilted back and into the affected side, with the bilateral side - tilts back, which creates the impression of stiff neck muscles.

The neuralgic syndrome of the defeat of the cervical plexus is expressed by pain in the occipital region, posterolateral surface of the neck and in the ear lobe. In this zone, sensitivity disorders are possible.

[1], [2], [3], [4], [5]