Long thoracic nerve. Injuries and diseases of peripheral nerves. Additional diagnostic methods

The somatic peripheral nervous system includes spinal nerve roots, spinal nodes, nerve plexuses, spinal and cranial nerves. Even within the spinal canal, the anterior (motor) and posterior (sensitive) roots gradually come closer together, then merge and form the radicular nerve along the spinal nodes, and then the spinal nerve. Therefore, the spinal nerves are mixed, since they contain motor (efferent) fibers from the cells of the anterior horns, sensory (afferent) fibers from the cells of the spinal ganglia and autonomic fibers from the cells of the lateral horns and nodes of the sympathetic trunk.

After leaving the central canal through the intervertebral foramina, the spinal nerves divide into anterior branches ( rr. anteriores), innervating the skin, muscles of the limbs and the anterior surface of the body; posterior branches ( rr. posteriores), innervating the skin and muscles of the posterior surface of the body; meningeal branches ( rr. meningei), heading towards the hard shell spinal cord, and connecting branches ( rr. communicantes), containing sympathetic preganglionic fibers that follow the nodes of the sympathetic trunk ( gangl. trunci sympathici). The anterior branches of the cervical, lumbar and sacral spinal nerves form bundles of corresponding plexuses, from which the peripheral nerves arise.

Nerve fiber (axon) is the main structural element of the peripheral nerve. There are myelinated and unmyelinated nerve fibers. Myelinated nerve fibers are divided into thick, which conduct pulses at a speed of 40–70 m/s, and thin, conducting pulses at a speed of 10–20 m/s. The speed of impulse conduction along unmyelinated nerve fibers is 0.7–1.5 m/s. Fibers with a thick myelin sheath provide complex and deep types of sensitivity (two-dimensional spatial sense, discriminatory sense, stereognosis, joint-muscular sense, etc.), fibers with a thin myelin sheath - pain, temperature and tactile, and non-myelinated fibers - only pain sensitivity. In this case, fibers with a thin myelin sheath are involved in the formation of the sensation of localized pain, without myelin - diffuse pain. Myelinated axons predominate in somatic (spinal and cranial) nerves, non-myelinated axons predominate in the visceral nerves of the sympathetic part of the autonomic nervous system; the nerves of its parasympathetic part (vagus, oculomotor nerve root, etc.) mainly consist of myelinated nerve fibers.

Nerve fibers are grouped into separate bundles of various calibers, delimited from other formations of the nerve trunk by the perineural sheath. On a cross section of human nerves, connective tissue sheaths (epineurium, perineurium) occupy significantly more space (67–84%) than bundles of nerve fibers. The bundles in the nerve trunks can be located relatively rarely, with intervals of 170–250 μm, and more often, the distance between the bundles is less than 85–170 μm.

The epineurium of nerves with a large number of bundles is replete with small-caliber blood vessels. In nerves with a small number of bundles, the vessels are single, but larger. The thickness of the bundles depends not only on the number, but also on the type of nerve fibers that make them up. More powerful bundles are formed by myelin fibers. Due to the fact that nerve fibers pass from one bundle to another, complex intra-stem plexuses are formed. This partly explains the absence of clear zones of impairment of motor, sensory and autonomic functions with partial nerve damage.

Cervical plexus (plexus cervicalis) (Fig. 24). The plexus is formed by the anterior branches of the four upper cervical spinal nerves (C 1 -C 4) and is located lateral to the transverse processes on the anterior surface of the middle scalene muscle and the levator scapula muscle, under the sternocleidomastoid muscle. Cutaneous and muscular branches emerge from it to the deep muscles of the neck, which are involved in the innervation of the scalp, ear, neck, diaphragm and shoulder girdle. When damaged, pain and sensitivity disorders occur in the innervation zone.

The cervical plexus forms the following nerves.

Lesser occipital nerve (n. occipitalis minor) is formed from the anterior branches of the C 1 - C 3 cervical spinal nerves. It innervates the skin of the lateral part of the occipital region and partially the auricle. When the nerve is irritated, occipital neuralgia occurs, and with compression-ischemic lesions, paresthesia occurs in the external occipital region.

Rice. 24. Cervical plexus:

1 – suboccipital nerve; 2 – greater occipital nerve; 3 – lesser occipital nerve; 4 – great auricular nerve; 5 – transverse nerve of the neck; 6 – supraclavicular nerves; 7 – phrenic nerve; 8 – neck loop; 9 – upper cervical node; 10 – hypoglossal nerve

Greater auricular nerve (n. auricularis magnus) is formed from the anterior branches of the C 3 -C 4 cervical spinal nerves and provides innervation to the earlobe, auricle and external auditory canal.

Transverse cervical nerve (n. transversus colli) is formed from the anterior branches of the C 2 -C 3 cervical spinal nerves and innervates the skin of the lateral and anterior regions of the neck.

Supraclavicular nerves (nn. supraclavicularis) are formed from the fibers of the anterior branches of the C 3 -C 4 cervical spinal nerves and innervate the skin of the supraclavicular, subclavian, suprascapular regions and the upper outer part of the shoulder.

Damage to the supraclavicular nerves is accompanied by pain syndrome in the innervation zone, increasing when the head is tilted to the sides. Intense pain is usually accompanied by tonic tension of the neck muscles, leading to a forced position of the head (in such cases, differential diagnosis with meningeal syndrome is necessary). In addition, there are disorders of surface sensitivity in the area of innervation and pain points along the posterior edge of the sternocleidomastoid muscle.

Phrenic nerve (n. phrenicus) is formed from C 3 -C 5 cervical spinal nerves, is mixed. It innervates the diaphragm, pleura, pericardium, peritoneum and liver ligaments. When the nerve is damaged, paralysis of the same half of the diaphragm occurs (it manifests itself in paradoxical breathing: when inhaling, the epigastric region sinks, when exhaling, it protrudes), and when irritated, hiccups, shortness of breath and pain in the hypochondrium, shoulder girdle and neck can be observed. Most often the nerve is affected by infectious diseases (diphtheria, influenza, scarlet fever, etc.), intoxication, tumor metastases in cervical vertebrae and etc.

Brachial plexus (plexus brachialis) (see Fig. 25 on color incl.). The plexus is formed by the connection of the anterior branches of the four lower cervical (C 5 -C 8) and two upper thoracic (Th 1 -Th 2) spinal nerves. Nerve fibers form primary bundles - upper, middle and lower, and then secondary bundles (lateral, medial and posterior). The upper bundle is formed from the fusion of the anterior branches of the C 5 -C 6 spinal nerves, the middle – C 7 and the lower – C 8 -Th 2. The brachial plexus is divided into supraclavicular and subclavian parts. The supraclavicular part of the brachial plexus is located in the supraclavicular fossa. The following nerves are formed from it.

Anterior thoracic nerves (rr. anteriores nn. thoracici) innervate the pectoral muscles: major (adducts and rotates the shoulder inward) and minor (pulls the scapula forward and downward). Isolated damage to these nerves is rare. Paresis or paralysis of these muscles is manifested by difficulty in bringing the upper limb to the chest.

Dorsal nerve of the scapula (n. dorsalis scapulae) innervates the rhomboid major and minor muscles and the levator scapulae muscle.

Long pectoral nerve (n. thoracicus longus) innervates the anterior serratus muscle, bringing the scapula closer to the chest.

Subclavian nerve (n. subclavius) innervates the subclavian muscle, which pulls the clavicle down and medially.

Suprascapular nerve (n. suprascapularis). The sensory part supplies the ligaments and capsule of the shoulder joint, the motor part supplies the supraspinatus and infraspinatus muscles (shoulder abduction at an angle of 15° and external rotation of the shoulder) (see color on, Fig. 25).

Thoracospinal nerve (n. thoracodorsalis) innervates latissimus muscle backs. Its defeat is accompanied by a violation of the movement of the arm back behind the back and to the midline, i.e., inward rotation.

Infraclavicular part of the brachial plexus located in armpit and innervates the hand. There are three bundles in it: lateral, formed by the anterior branches of the C 5 -C 7 nerves; medial – anterior branches of the C 8 and Th 1 nerves; posterior - posterior branches of the three primary bundles. The musculocutaneous nerve is formed from the lateral fascicle ( n. musculocutaneus) and lateral root median nerve (n. medianus); from the medial - ulnar nerve ( n. ulnaris), medial cutaneous nerve of the shoulder ( n. cutaneus brachii medialis) and forearms ( ), medial root of the median nerve; from the posterior - axillary nerve ( n. axillaris) and radial nerve ( n. radialis).

Median nerve (n. medianus) contains motor, sensory and big number vegetative fibers. Innervates the muscles of the anterior surface of the forearm; flexors of the hand and I–II fingers, pronators of the forearm and hand, the muscle opposing the thumb and I–II lumbrical muscles; the skin of the palmar surface of the radial edge of the hand, I–III and half of the IV fingers, the dorsal surface of the terminal phalanges of the I–II and partially IV fingers. When the median nerve is damaged, flexion of the hand and fingers I–III, opposition thumb and pronation (it is difficult to grasp objects), flexion of the proximal phalanges and extension of the remaining phalanges of the II–III fingers. The muscles of the forearm and the eminence of the thumb atrophy, a “monkey hand” is formed, and vegetative-trophic disorders (regional pain syndrome, causalgia) may appear. Deep sensitivity is lost in the terminal interphalangeal joint of the second finger.

The nerve is often damaged in natural anatomical tunnels. In this case, a distinction is made between the supracondylar-ulnar groove syndrome (provoked by extension of the forearm and pronation in combination with forced flexion of the fingers and is accompanied by pain, paresthesia in the innervation zone of the median nerve, weakness of the flexors of the hand and fingers); syndrome pronator teres(symptoms of loss of function of the median nerve intensify with pressure in the area of the pronator teres); carpal tunnel syndrome (the main symptom is paresthesia and pain in the fingers, aggravated by the wrist flexion test and tapping along the projection of the median nerve at the level of the wrist).

Ulnar nerve (n. ulnaris) innervates the flexors of the fourth and fifth fingers, all interosseous, third and fourth lumbrical muscles, the muscle that adducts the first finger and abductor the fifth finger. Provides sensitive innervation to the palmar surface of the 5th and half of the 4th, as well as the dorsal surface of the 5th, 4th and half of the 3rd fingers.

When the nerve is damaged, flexion of the little finger, abduction and adduction of the fingers (the patient cannot grasp and hold objects between the fingers), flexion of the proximal and extension of the remaining phalanges of the fourth and fifth fingers are impaired. Arises partial atrophy muscles of the forearm, the interosseous spaces of the hand sink and the elevation of the little finger (“clawed paw”) becomes flattened. Sensory disorders spread to the ulnar part of the hand from the palm and back, the area of the V and ulnar side of the IV fingers. Deep sensitivity is impaired in the joints of the fifth finger.

The following are distinguished: ulnar nerve tunnel syndromes: cubital syndrome (with rheumatoid arthritis, prolonged sitting at a desk, paresthesia and numbness first appear in the area of innervation of the ulnar nerve, and later weakness and atrophy of the hand muscles); wrist syndrome (paresthesia on the inner surface of the hand, weakness in flexion and adduction of the fifth finger, aggravated by digital compression and tapping on the wrist).

Medial cutaneous nerve of the shoulder (n. cutaneus brachii medialis) innervates the skin of the inner surface of the shoulder. It is affected by prolonged walking on crutches or scarring in the upper third of the shoulder.

Medial cutaneous nerve of the forearm (n. cutaneus antebrachii medialis) innervates the skin of the inner surface of the forearm. It is affected by scar processes along the medial surface of the middle and lower third of the shoulder.

Clinical signs of damage to these nerves are paresthesia, pain, and numbness in the innervation zone.

Axillary nerve (n. axillaris) innervates the deltoid muscle, which abducts the shoulder to a horizontal level, and is also involved in flexion and extension of the shoulder (movement of the shoulder forward and backward), rotation of the shoulder outward (teres minor muscle) and provides sensitive innervation of the skin in the area of the shoulder joint and the outer surface of the shoulder in its upper third. Nerve damage is manifested by pain in the shoulder joint, impaired abduction of the upper limb to the side, lifting it forward and backward, hypotrophy deltoid muscle(differential diagnosis must be made with glenohumeral periarthrosis and cervicothoracic radiculopathy).

Radial nerve (n. radialis) innervates the triceps brachii muscle, extensors of the hand and fingers, supinator of the forearm, brachioradialis muscle and abductor muscle of the first finger of the hand. Provides sensitive innervation to the posterior region of the shoulder and forearm, the radial part of the dorsum of the I, II and partially III fingers. If the radial nerve is damaged, the extension of the forearm, hand and fingers, and the abduction of the first finger are disrupted. Atrophies triceps shoulder (“dangling hand”, Fig. 26). The extensor-elbow and carporadial reflexes decrease or disappear, and sensitivity in the innervation zone is disrupted.

There are lesions of the radial nerve in the axilla (with fractures of the humerus), at the level of the intermuscular septum of the shoulder (“sleep paralysis”), in the area elbow joint and upper part of the forearm (lipomas, fibromas of this area, bursitis, synovitis of the elbow joint, etc.), supinator syndrome, Turner syndrome (compression of the radial nerve due to a fracture of the lower end of the radius).

Clinical symptoms of brachial plexus lesions depends on the location and extent of the pathological process. Thus, when the upper primary bundle is damaged (with injuries, prolonged throwing of hands behind the head during surgery, tumor metastases, etc.) upper Erb-Duchenne palsy, characterized by damage to the proximal part of the upper limb while the function of the hand and fingers is preserved. The hand hangs like a whip. The reflex from the biceps brachii muscle disappears, and the carporadial one decreases. The sensitivity of the radicular type (C 5 -C 6) on the outer surface of the shoulder and forearm is upset. One of the clinical forms of compression-ischemic damage to the superior bundle of the brachial plexus is Personage-Turner neuralgic amyotrophy, which begins with increasing pain in the area of the shoulder girdle, shoulder and scapula and gradually turns into deep paresis of the proximal parts of the arm with distinct atrophy of the serratus anterior, deltoid and parascapular muscles.

Rice. 26.“Dangling hand” with damage to the radial nerve

Damage to the primary inferior bundle of the plexus causes Dejerine-Klumpke lower palsy, in which distal paralysis occurs with predominant damage and atrophy small muscles and flexors of the fingers and hand. Sometimes, with high damage, Horner's syndrome occurs. Sensitivity is impaired in a radicular manner (C 8 -Th 2) on the inner surface of the hand, forearm and shoulder.

With total damage to the brachial plexus (with gunshot wounds of the supra- and subclavian areas, with a fracture of the clavicle, 1st rib, with a dislocation of the humerus, tumors or metastases of this localization, etc.), peripheral paralysis of the arm occurs and shoulder girdle with sensitivity disorder and pain in the neck, scapula, arm, with loss of the extensor-elbow, flexion-elbow and carporadial reflexes. The brachial plexus is most often affected in muscular-tonic syndromes cervical osteochondrosis(eg, Naffziger anterior scalene syndrome; scalenus syndrome; small pectoral muscle– Wright-Mendlovich hyperabduction syndrome; Steinbrocker shoulder-hand syndrome; Paget–Schroetter syndrome with thrombosis of the subclavian vein).

Thoracic nerves (nn. thoracici) are mixed, formed from Th 2 -Th 12 roots. The anterior branches of the thoracic nerves are intercostal. The first six intercostal nerves innervate the muscles and skin of the anterior and lateral sections chest, six lower - muscles and skin of the anterior abdominal wall. The posterior branches of the thoracic nerves innervate the muscles and skin of the back. When the intercostal nerves are damaged, girdling and constricting pain occurs and sensitivity in the corresponding zones is disrupted, reflexes are lost, and muscle paresis develops. abdominals. When spinal nodes are involved in the pathological process (ganglioneuritis), a rash in the form of vesicles is observed ( herpes zoster).

Lumbar plexus (plexus lumbalis) (Fig. 27, A) is formed from the anterior branches of the lumbar (L 1 -L 4) spinal nerves and partially the anterior branches of the 12th thoracic nerve. Located anterior to the transverse processes of the lumbar vertebrae on the anterior surface of the quadratus lumborum muscle, in the thickness of the large muscle psoas muscle.

The following nerves emerge from the plexus: iliohypogastric, ilioinguinal, femorogenital, femoral, obturator, lateral cutaneous nerve of the thigh. Damage to the entire plexus is rare (with fractures of the spine and pelvic bones; with compression by tumors, hematoma, pregnant uterus; with inflammatory processes in the retroperitoneal space); individual trunks are much more often affected. The clinical picture of lumbar plexopathy is characterized by pain in the lower abdomen, lumbar region, pelvic bones; reduction of all types of sensitivity of the skin of the pelvic girdle and thighs; movement disorder in lumbar region spine, hip and knee joints.

Iliohypogastric nerve (n. iliohypogastricus) is formed from the anterior branches of the Th 12 and L 1 spinal nerves. Innervates the transverse, rectus and oblique abdominal muscles, the skin of the suprapubic region and the upper lateral region of the thigh. It is usually damaged during operations on the abdominal or pelvic organs (especially during hernia repair).

Ilioinguinal nerve (n. ilioinguinalis) is formed from the anterior branch of L 1. Innervates the lower sections of the transverse, internal and external oblique muscles of the abdomen, the skin of the upper section of the inner surface of the thigh, genitals and groin area. Usually damaged during operations for hernia repair, appendectomy, nephrectomy; The development of compression-ischemic (tunnel) neuropathy is also possible. Nerve damage is manifested by pain and paresthesia in the groin area, antalgic posture when walking and limited extension, internal rotation and abduction of the hip.

Femorogenital nerve (n. genitofemoralis) is formed from the anterior branches of the L 1 -L 2 spinal nerves. Motor fibers innervate m. cremaster And tunica dartos, sensitive – the skin of the front and inner thighs in the upper third. When the nerve is damaged, the cremasteric reflex decreases or disappears and sensitivity disorders occur (most often pain in the groin area) in the corresponding area.

Femoral nerve (n. femoralis) is formed from the anterior branches of the L 1 -L 4 spinal nerves. Innervates the iliopsoas muscle (flexes the thigh at the hip joint and the spine in the lumbar region), the quadriceps femoris muscle (flexes the thigh and lower leg, turns the bent lower leg inward). Sensitive fibers innervate the skin of the lower two-thirds of the anterior surface of the thigh and the anterior inner surface of the leg. It is affected by injuries, spontaneous hematomas along its course, inguinal lymphadenitis, appendicular abscess, etc.

Rice. 27. Lumbosacral plexus:

A– lumbar plexus: 1 – iliohypogastric nerve; 2 – ilioinguinal nerve; 3 – genitofemoral nerve; 4 – lateral cutaneous nerve of the thigh; 5 – obturator nerve; 6 – femoral nerve.

B– sacral plexus: 7 – superior gluteal nerve; 8 – inferior gluteal nerve; 9 – sciatic nerve; 10 – common peroneal nerve; 11 – tibial nerve; 12 – posterior cutaneous nerve of the thigh; 13 – pudendal nerve ( n. pudendum); 14 – coccygeal nerve ( n. coccygeus)

When the nerve below the inguinal ligament is damaged, pain first occurs in the groin area, radiating to the lower back and thigh; Extension of the lower leg is impossible, atrophy of the quadriceps femoris muscle is noticeable, the knee reflex is lost, sensitivity on the anterior inner surface of the lower leg is impaired. If the nerve above the inguinal ligament is damaged, sensitivity disorders on the anterior surface of the thigh, impaired flexion of the hip (bringing it to the stomach) and lifting of the body in supine position; gait is difficult (the leg is excessively extended in knee joint) and especially climbing stairs. When the nerve is irritated, Wassermann's symptom appears: with the patient lying on his stomach, lifting a straight leg or bending the knee joint causes pain in the groin area or along the front surface of the thigh.

Obturator nerve (n. obturatorius) is formed from the anterior branches of the L 4 -L 5 spinal nerves and is located behind or inside the psoas major muscle. Motor fibers innervate the hip adductor muscles. Sensory fibers innervate the lower half of the inner thigh. Nerve damage is possible at the beginning of its discharge (with a retroperitoneal hematoma).

If the nerve is damaged, it is difficult to adduct the leg, it is impossible to put one leg on the other, and in addition, there are sensory disturbances in the corresponding area.

Lateral cutaneous nerve of the thigh (n. cutaneus femoris lateralis) is formed from fibers of the roots L 2 -L 3 and innervates the skin of the outer surface of the thigh. When a nerve is damaged, sensitivity disorders occur in the innervation zone; when irritated, paresthesia and numbness occur in the same area of the skin (Bernhardt-Roth disease, or meralgia paresthetica).

Sacral plexus (plexus sacralis ) (Fig. 27, B). Formed from the anterior branches of the L 4 -S 3 roots, located on the anterior surface of the sacrum and piriformis muscle. The nerves emanating from it exit through the greater sciatic foramen. The sacral plexus connects to the lumbar plexus through the anterior branch of the S 1 spinal nerve. Defeat sacral plexus or its constituent roots causes loss of function of the nerves emerging from it.

Superior gluteal nerve (n. gluteus superior) is formed from fibers of L 4, L 5 and S 1 roots. Innervates the gluteus minimus and medius muscles and the tensor fascia lata, which abduct the thigh outward. If this nerve is damaged, hip abduction is difficult; Bilateral lesions are characterized by a “duck” gait.

Inferior gluteal nerve (n. gluteus inferior) is formed from fibers of L 5, S 1, S 2 roots and innervates the large gluteal muscle and joint capsule hip joint. When the nerve is damaged, extension (abduction backwards) of the hip and straightening of the torso when standing in a bent forward position are impaired.

Posterior cutaneous nerve of the thigh (n. cutaneus femoris posterior) is formed from the anterior branches of the S 1 -S 2 roots and innervates the skin of the lower buttocks, scrotum (labia majora), perineum and posterior thigh to the popliteal fossa.

Sciatic nerve (n. ischiadicus) is a direct continuation of the anterior branches of the L 4 -S 3 spinal nerves. At the level of the thigh, the nerve gives off branches to the biceps femoris, semimembranosus and semitendinosus muscles, which flex the lower leg and rotate it outward or inward. In the upper part of the popliteal fossa, the sciatic nerve is divided into the tibial and common peroneal nerves, although the subepineural separation of both portions of the nerve usually occurs in the pelvic cavity.

In case of defeat sciatic nerve above the gluteal fold, there is an inability to flex the leg, as well as loss of function of the peroneal and tibial nerves (paralysis of the foot and fingers, loss of the Achilles reflex and anesthesia of the entire leg and foot). In addition, damage to the sciatic nerves is often accompanied by severe pain. When the nerve is irritated, Lasegue's symptom is characteristic: pain along the sciatic nerve when raising the leg straightened at the knee joint in a supine position. When the sciatic nerve is affected below the gluteal fold, as a rule, predominantly the peroneal or tibial nerve is affected.

Common peroneal nerve (n. peroneus communis) is formed from L 4 -S 2 spinal nerves. Its main branches are the superficial peroneal ( n. peroneus superficialis) and deep peroneal nerve ( n. peroneus profundus). The muscular branches of the superficial peroneal nerve innervate the long and brevis peroneus muscles, which elevate the outer edge of the foot, causing the foot to pronate and abduct, and the cutaneous branches innervate the dorsum of the foot and the lateral region of the leg. When the nerve is damaged, abduction and elevation of the outer edge of the foot are disrupted, and sensitivity in the corresponding area is disrupted.

The muscular branches of the deep peroneal nerve innervate the tibialis anterior muscle, the long and short extensor toes, which extend, adduct and supinate the foot, straighten the proximal phalanges of the toes; cutaneous branches - a wedge-shaped area of the skin of the dorsum of the foot between the first and second toes. Damage to the nerve leads to impaired dorsiflexion of the toes, atrophy of the anterior group of leg muscles, and sensitivity disorder in the corresponding area. Signs of damage to the common peroneal nerve are foot drop (“horse foot”), inability to extend the foot, “cock” gait (steppage) (Fig. 28), inability to stand and walk on heels, sensitivity disorder on the dorsum of the foot and in the lateral region of the lower leg.

Tibial nerve (n. tibialis) is formed from L 4 -S 3 spinal nerves. The muscle branches innervate the triceps surae muscle (flexes the foot), tibialis posterior muscle (flexes the foot, rotates it outward and adducts), flexor toes (flexes the foot and its toes). Sensitive branches innervate the posterior region of the leg, the sole and plantar surface of the fingers with access to the rear of the distal phalanges and the lateral edge of the foot.

When the tibial nerve is damaged, the foot takes on a specific appearance: a protruding heel, a deepened arch and a claw-like position of the toes ( pes calcaneus); inability to plantar flex the foot and its toes, walk and stand on the toes. Sensitivity in the posterior region of the leg, sole, and toes decreases, and vegetative-trophic disorders and causalgia often occur.

Rice. 28."Cock" gait (steppage) with damage to the peroneal nerve

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Anatomy and etiology of long thoracic nerve compression. The long thoracic nerve is a purely motor nerve that arises from the ventral rami of the spinal nerves C5, C6, and C7. It passes along with the other components of the brachial plexus under the clavicle, then descends down the anterolateral chest wall to the serratus anterior muscle. This large muscle attaches the scapula to the chest wall, providing overall stability to the shoulder when moving the arm. Damage to the long thoracic nerve can occur due to trauma or severe physical activity, involving the shoulder girdle in movement. Long thoracic nerve neuropathy may be due to idiopathic brachial plexus plexopathy.

Clinical picture of the long thoracic nerve long thoracic nerve mononeuropathy involves pain and weakness in shoulder joint. Patients experience difficulty abducting the arm or raising it above the head. In the patient's position with arms extended forward and emphasis on the wall, the phenomenon of the “pterygoid scapula” appears. The shoulder blade rises above the chest because the weakened serratus muscle cannot support it.

Long thoracic nerve diagnosis established on the basis of the above-mentioned clinical signs and the detection of fibrillation potentials on EMG affecting only the serratus anterior muscle. Determining the velocity of potential conduction along the long thoracic nerve (LPNV) is technically difficult; LPNVs of other nerves are normal.

Suprascapular nerve. Compression of the suprascapular nerve.

Anatomy and etiology of suprascapular nerve compression. The suprascapular nerve is a purely motor nerve that arises from the superior cord of the brachial plexus and passes through the suprascapular notch along the superior edge of the scapula to the supraspinatus and cavitary muscles. The suprascapular nerve is most often injured in injuries associated with excessive anterior flexion of the shoulder joint.

He may get involved in pathological process with idiopathic brachial plexus plexopathy.

Clinical picture consists of pain in the back of the shoulder joint and weakness of the supraspinatus and infraspinatus muscles. The supraspinatus muscle provides abduction of the arm, while the infraspinatus muscle is responsible for external rotation of the arm.

Diagnosis established on the basis of anamnesis, clinic, physical data and EDI. Conventional studies of the SPNV are normal, but a study of the SPNV of the motor nerves with recording from the supraspinatus muscle may reveal a decrease in amplitude or prolongation of the latency period compared with the healthy side.

Posterior scapular nerve

Anatomy and etiology of posterior scapular nerve compression. The posterior scapular nerve (PSN) is a purely motor nerve that originates from the superior fascicle of the brachial plexus and passes through the middle scalene muscle to the rhomboid and levator scapulae muscles. PLN lesions are relatively rare.

Clinical picture of compression of the posterior scapular nerve includes pain in the scapula region and weakness of the rhomboid and levator scapulae muscles.

Diagnosis of posterior scapular nerve compression established on the basis of clinical signs and EMG data identifying fibrillation potentials related to the muscles innervated by the ON. For PLN, there are no satisfactory methods for assessing PNV.

The short branches of the brachial plexus include the dorsal (posterior) nerve of the scapula, long thoracic, subclavian, suprascapular, subscapular, thoracodorsal, lateral and medial thoracic nerves, and axillary nerves. The muscular branches also belong to the short branches of the brachial plexus; they innervate the scalene muscles and the splenius neck muscle.

The dorsal nerve of the scapula (n. dorsalis scapulae) arises from the anterior branches of the fourth and fifth cervical spinal nerves. The nerve passes along the anterior surface of the levator scapulae muscle, then between the middle and posterior scalene muscles and branches into the rhomboid major and minor muscles and the levator scapulae muscle.
The long thoracic nerve (n. thoracicus longus) originates from the anterior branches of the fifth and sixth spinal nerves (CV-CVI) and goes behind the brachial plexus. Next, the nerve is located between the subscapularis and serratus anterior muscles, goes down between the lateral thoracic artery in front and the thoracodorsal artery in the back. Innervates the serratus anterior muscle.
The subclavian nerve (n. subclavius) is formed by the anterior branch of the fifth spinal nerve. Nerve the shortest route goes down the outer edge of the anterior scalene muscle to the subclavian muscle. Often the subclavian nerve gives off a branch to the phrenic nerve.
The suprascapular nerve (n. suprascapularis) is formed by the anterior branches of the fifth and sixth spinal nerves. It is separated directly from the superior bundle of the brachial plexus. Initially, the nerve passes near the upper edge of the brachial plexus under trapezius muscle and the lower belly of the omohyoid muscle. Further behind the clavicle, the nerve forms a bend laterally and posteriorly, passes into the supraspinatus fossa through the notch of the scapula under its superior transverse ligament. Then, together with the transverse scapular artery, the suprascapular nerve passes under the base of the acromion into the infraspinatus fossa. Innervates the supraspinatus and infraspinatus muscles, the capsule of the shoulder joint.
The subscapular nerve (n. subscapularis) departs from the anterior branches of the fifth to seventh spinal nerves in two or three trunks and runs along the anterior surface of the subscapularis muscle. Innervates the subscapularis and teres major muscles.
The thoracodorsal nerve (n. thoracodorsalis) is formed from the anterior branches of the fifth to seventh spinal nerves and is directed down along the outer edge of the scapula to the latissimus dorsi muscle, which it innervates.
The lateral and medial thoracic nerves (nn. pectorales lateralis et medialis) originate from the lateral and medial fascicles of the brachial plexus (CV-ThI). The nerves run forward, pierce the clavipectoral fascia and end in the pectoralis major (medial nerve) and pectoralis minor (lateral nerve) muscles.
The axillary nerve (n. axillaris) starts from the posterior bundle of the brachial plexus (CV-CVIII). The nerve runs laterally and down the anterior surface of the subscapularis muscle, then turns back. Together with the posterior circumflex artery of the humerus, the nerve passes through the quadrilateral foramen and exits onto the dorsum of the shoulder. The nerve then enters the deltoid muscle from the lateral surface of the surgical neck of the humerus, giving off a small branch to the teres minor muscle and the capsule of the shoulder joint. The final branch of the axillary nerve is the superior lateral cutaneous nerve of the shoulder (n. cutaneus brachii lateralis superior), which exits under the skin between the posterior edge of the deltoid muscle and the long head of the triceps brachii muscle and innervates the skin above the deltoid muscle and in the lateral part of the shoulder.

Long branches of the brachial plexus

The long branches of the brachial plexus arise from the lateral, medial and posterior bundles of the infraclavicular part of the brachial plexus. Among the long branches, the musculocutaneous, median, ulnar nerves, medial cutaneous nerve of the shoulder, medial cutaneous nerve of the forearm and radial nerve are distinguished.

The musculocutaneous nerve (n. musculocutaneus) arises from the lateral bundle of the brachial plexus. This nerve is formed by the anterior rami of the fifth through eighth (CV-CVIII) cervical spinal nerves. The musculocutaneous nerve runs downward and laterally, pierces the coracobrachialis muscle and gives off branches to it. Initially, the nerve is located lateral to the median nerve, then it is separated from it downwards. On the shoulder, the musculocutaneous nerve passes between the brachialis and biceps brachii muscles, giving off muscular branches to them (rr. musculares). At the level of the elbow joint, lateral to the terminal portion of the biceps brachii tendon, the musculocutaneous nerve pierces the fascia of the shoulder and continues into the lateral cutaneous nerve of the forearm (n. cutaneus anteabrachii lateralis), which descends under the skin along the lateral side of the forearm. The lateral cutaneous nerve of the forearm innervates the skin of this area up to the eminence of the thumb.
The median nerve (n. medianus) arises from the confluence of the lateral and medial fascicles of the brachial plexus formed by the fibers of the anterior branches of the sixth-eighth cervical and first thoracic (CVI-ThI) spinal nerves. Both bundles connect at an acute angle in front of the axillary artery. On the shoulder, the median nerve initially passes in the same fascial sheath with the brachial artery, located lateral to it. The projection of the median nerve corresponds to the location medial sulcus shoulder

The ulnar nerve (n. ulnaris) arises from the medial bundle of the brachial plexus. It consists of fibers of the anterior branches of the eighth cervical - first thoracic (CVIII-ThI) spinal nerves. Initially, the ulnar nerve is located adjacent to the median nerve and just medial to the brachial artery. In the middle third of the shoulder, the nerve deviates to the medial side, then pierces the medial intermuscular septum shoulder and goes down to the posterior surface of the medial epicondyle of the humerus.

The medial cutaneous nerve of the shoulder (n. cutaneus brachii medialis) is formed by fibers of the anterior branches of the eighth cervical and first thoracic spinal nerves (CVIII-ThI), departs from the medial fascicle of the brachial plexus and accompanies the brachial artery. At the base of the axillary cavity, the medial cutaneous nerve of the shoulder connects with the lateral cutaneous branches of the second and third intercostal nerves and is called the intercostobrachial nerve (n. intercostobrachialis). Next, the medial cutaneous nerve of the shoulder pierces the axillary and brachial fascia and branches in the skin of the medial side of the shoulder to the medial epicondyle of the humerus and the olecranon process of the ulna.
The medial cutaneous nerve of the forearm (n. cutaneus antebrachii medialis) consists of fibers of the anterior branches of the eighth cervical - first thoracic (CVII-ThI) spinal nerves. It emerges from the medial bundle of the brachial plexus and is adjacent to the brachial artery. Initially, the nerve is located deep in the shoulder, then pierces the fascia of the shoulder at the junction of the medial saphenous vein of the arm into one of the brachial veins. Branches of the medial cutaneous nerve of the forearm innervate the skin of the medial side of the lower arm and the posterior non-medial side of the forearm.
The radial nerve (n. radialis) is a continuation of the posterior bundle of the brachial plexus. It consists of fibers of the anterior branches of the fifth cervical-first thoracic (CV-ThI) spinal nerves.

Brachial plexus(plexus brachialis) formed by the anterior branches of the V-VIII and partly of the I thoracic spinal nerves. In the interscalene space, nerves form three trunks (upper, middle And lower), which pass between the anterior and middle scalene muscles into the supraclavicular fossa and descend into the axillary cavity behind the clavicle (Fig. 83). The plexus is divided into supraclavicular and subclavian parts. From supraclavicular part (pars supraclavicularis) short branches arise that innervate part of the muscles of the neck, the muscles of the shoulder girdle and the shoulder joint. Subclavian part (pars infraclavicularis) divided into lateral, medial and posterior bundles, which surround the axillary Rice. 83. Cervical and brachial plexuses and their branches, right view. The middle part of the clavicle, subclavian artery and vein, and the superior belly of the omohyoid muscle were removed. The pectoralis major muscle is cut and turned down: 1 - cervical plexus; 2 - neck loop; 3 - phrenic nerve; 4 - vagus nerve; 5 - anterior scalene muscle; 6 - common carotid artery; 7 - brachial plexus; 8 - subclavian artery (cut off); 9 - lateral and medial thoracic nerves; 10 - anterior cutaneous branches (intercostal nerves); 11 - long thoracic nerve; 12 - intercostal-brachial nerves; 13 - medial bundle of the brachial plexus; 14 - lateral bundle; 15 - axillary artery; 16 - supraclavicular nerves; 17 - middle scalene muscle; 18 - lesser occipital nerve; 19 - external carotid artery; 20 - internal jugular vein (cut off); 21 - hypoglossal nerve artery. From medial bundle (fasciculus medialis) the cutaneous nerves of the shoulder and forearm, the ulnar and medial root of the median nerve depart from lateral bundle (fasciculus lateralis)- lateral root of the median nerve and musculocutaneous nerve, from posterior bundle (fasciculus posterior)- radial and axillary nerves. Data on the largest nerves of the brachial plexus are given in Table. 5. The innervation of the skin of the upper limb is shown in Fig. 84.

The brachial plexus has short and long branches. The short branches extending from the supraclavicular part of the brachial plexus include dorsal scapular nerve, long thoracic nerve, subclavian, subscapular, suprascapular, thoracodorsal, axillary, lateral and medial thoracic nerves, as well as muscle branches innervating the scalene muscles and the splenius muscle of the neck. Dorsal nerve of the scapula(nervus dorsalis scapulae) lies on the anterior surface of the levator scapulae muscle, then between this muscle and the posterior scalene muscle it is directed posteriorly along with the descending branch of the transverse artery of the neck. This nerve innervates the levator scapulae muscle and the rhomboid major and rhomboid minor muscles. Long thoracic nerve(nervus thoracicus longus) descends down behind the brachial plexus, lies on the lateral surface of the anterior scalene muscle between the lateral thoracic artery in front and the thoracodorsal artery behind. Innervates the serratus anterior muscle. Subclavian nerve(nervus subclavius) passes in front of the subclavian artery, goes to the subclavian muscle, which it innervates. Suprascapular nerve(nervus suprascapularis) first passes near the upper edge of the brachial plexus under the trapezius muscle and the lower belly of the omohyoid muscle. Further behind the clavicle, the nerve forms a bend laterally and posteriorly, passes into the supraspinatus fossa through the notch of the scapula, under its superior transverse ligament. Then, together with the transverse artery of the scapula, the suprascapular Table 5. Nerves of the brachial plexus End of Table 5. Rice. 84. Distribution of cutaneous innervation of the upper limb: A - anterior side: 1 - medial cutaneous nerve of the shoulder; 2 - medial cutaneous nerve of the forearm; 3 - superficial branch of the ulnar nerve; 4 - common palmar digital nerve (from the ulnar nerve); 5 - own palmar digital nerves (from the ulnar nerve); 6 - own palmar digital nerves (from the median nerve); 7 - common palmar digital nerves (from the median nerve); 8 - superficial branch of the radial nerve; 9 - palmar branch of the median nerve; 10 - lateral cutaneous nerve of the forearm (branch of the musculocutaneous nerve); 11 - lower lateral cutaneous nerve of the shoulder (from the radial nerve); 12 - upper lateral cutaneous nerve of the shoulder (from the axillary nerve); 13 - supraclavicular nerves (branches of the cervical plexus); B - posterior side: 1 - upper lateral cutaneous nerve of the shoulder (from the axillary nerve); 2 - posterior cutaneous nerve of the shoulder (from the radial nerve); 3 - posterior cutaneous nerve of the forearm (from the radial nerve); 4 - lateral cutaneous nerve of the forearm; 5 - superficial branch of the radial nerve; 6 - dorsal digital nerves (from the radial nerve); 7 - dorsal digital nerves (from the ulnar nerve); 8 - dorsal branch of the ulnar nerve; 9 - medial cutaneous nerve of the forearm; 10 - medial cutaneous nerve of the shoulder

the nerve passes under the base of the acromion into the infraspinatus fossa. Innervates the supraspinatus and infraspinatus muscles, the capsule of the shoulder joint. Subscapular nerve(nervus subscapularis) runs along the anterior surface of the subscapularis muscle. Innervates the subscapularis and teres major muscles. Thoracodorsal nerve(nervus thoracodorsalis) runs along the lateral edge of the scapula, descends to the latissimus dorsi muscle and innervates it. Lateral and medial thoracic nerves(nn. pectorales lateralis et medialis) they begin from the lateral and medial bundles of the subclavian part of the brachial plexus, go forward, pierce the clavipectoral fascia and innervate the pectoralis major and minor muscles. Axillary nerve(nervus axillaris) departs from the subclavian part, from the posterior bundle of the brachial plexus, goes down and laterally near the anterior surface of the subscapularis muscle. The nerve then turns posteriorly, passes along with the posterior circumflex artery of the humerus through the quadrilateral foramen, bends around the surgical neck of the humerus from behind, and lies under the deltoid muscle. The nerve gives away muscle branches to the deltoid muscle, teres minor muscle, and capsule of the shoulder joint. Originates from the axillary nerve superior lateral cutaneous nerve of the shoulder (nervus cutaneus brachii lateralis superior), which bends around the posterior edge of the deltoid muscle and innervates the skin of the posterolateral region of the shoulder and deltoid region (Fig. 85). Rice. 85. Long branches of the brachial plexus, view from the anteromedial side. The pectoralis major and minor muscles are cut off and removed: 1 - lateral bundle; 2 - rear beam; 3 - medial bundle; 4 - axillary artery; 5 - subscapular nerve; 6 - subscapularis muscle; 7 - subscapular artery; 8 - artery circumflexing the scapula; 9 - thoracodorsal nerve; 10 - thoracodorsal artery; 11 - latissimus dorsi muscle; 12 - medial cutaneous nerve of the shoulder; 13 - radial nerve; 14 - deep artery of the shoulder; 15 - triceps brachii muscle; 16 - ulnar nerve; 17 - medial cutaneous nerve of the forearm; 18 - medial epicondyle; 19 - lateral cutaneous nerve of the forearm; 20 - biceps brachii; 21 - superior ulnar collateral artery; 22 - median nerve; 23 - brachial artery; 24 - coracobrachialis muscle; 25 - pectoralis major muscle; 26 - axillary nerve; 27 - musculocutaneous nerve; 28 - deltoid muscle; 29 - pectoralis minor muscle; 30 - deltoid branch (from the thoracoacromial artery); 31 - thoracoacromial artery

The long branches of the brachial plexus include the medial cutaneous nerves of the shoulder and forearm, the musculocutaneous, ulnar, radial and median nerves. Medial cutaneous nerve of the shoulder(ne'rvus cutane'us brachii medialis) originates from the medial bundle of the brachial plexus and accompanies the brachial artery. Two or three of its branches pierce the axillary fascia and the fascia of the shoulder and innervate the skin of the medial side of the shoulder to the elbow joint. At the base of the axillary cavity, the medial cutaneous nerve of the shoulder connects with the lateral cutaneous branch of the second and third intercostal nerves and forms intercostobrachial nerve (nervus intercostobrachialis).Medial cutaneous nerve of the forearm(nervus cutaneus antebrachii medialis) departs from the medial bundle of the brachial plexus, is adjacent to the brachial artery, descends to the forearm, where it gives off front And posterior branches (ramus anterius, ramus posterior). Innervates the skin of the ulnar (medial) side of the forearm (and the anterior surface) to the wrist joint. Ulnar nerve(nervus ulnaris) departs from the medial bundle of the brachial plexus, goes along with the median nerve and brachial artery in the medial groove of the biceps brachii muscle (Fig. 86). Then the nerve deviates medially and posteriorly, pierces the medial intermuscular septum of the shoulder, and bends around the medial epicondyle of the humerus from behind. The ulnar nerve does not give off branches on the shoulder. Next, the ulnar nerve gradually shifts to the anterior surface of the forearm, where it first passes between the muscle bundles of the initial part of the flexor carpi ulnaris. Below, the nerve is located between the flexor carpi ulnaris medially and the flexor digitorum superficialis muscle laterally. At the level of the lower third of the forearm, it runs in the ulnar groove of the forearm next to and medial to the arteries and veins of the same name. Closer to the head of the ulna, it departs from the ulnar nerve dorsal branch (r. dorsalis), which on the back of the hand goes between this bone and the tendon of the flexor carpi ulnaris. In the forearm, muscle branches innervate the flexor carpi ulnaris and the medial part of the deep flexor digitorum.

The dorsal branch of the ulnar nerve on the dorsum of the hand divides into five dorsal digital branches. These branches innervate the skin of the dorsum of the hand on the ulnar side, the skin of the proximal phalanges of the fourth and fifth fingers and the ulnar side of the third finger. Palmar branch (r. palmaris) of the ulnar nerve together with the ulnar artery, it passes to the palm through a gap in the medial part of the retinaculum Rice. 86. Ulnar nerve and other nerves of the left upper limb, anterior view. The biceps brachii muscle is turned to the side: 1 - musculocutaneous nerve; 2 - coracobrachial muscle; 3 - biceps brachii; 4 - brachial artery; 5 - median nerve; 6 - brachialis muscle; 7 - lateral cutaneous nerve of the forearm; 8 - brachioradialis muscle; 9 - aponeurosis of the biceps brachii muscle; 10 - medial epicondyle of the humerus; 11 - inferior ulnar collateral artery; 12 - superior ulnar collateral artery; 13 - medial head of the triceps brachii muscle; 14 - ulnar nerve; 15 - radial nerve; 16 - posterior bundle of the brachial plexus; 17 - medial bundle of the brachial plexus; 18 - axillary artery; 19 - lateral bundle of the brachial flexor plexus, on the lateral side of the pisiform bone. Near the uncinate process of the hamate, the palmar branch divides into superficial and deep branches. Superficial branch (r. superficialis) located under the palmar aponeurosis. A branch first extends from it to the palmaris brevis muscle. Then it is divided into common palmar digital nerve (p. digitalis palmaris communis) And own palmar nerve. The common palmar digital nerve passes under the palmar aponeurosis and divides into two proper palmar digital nerves in the middle of the palm. They innervate the skin of the sides of the IV and V fingers facing each other, as well as the skin of their dorsal surfaces in the region of the middle and distal phalanges. Own palmar digital nerve (p. digitalis palmaris prtoprius) innervates the skin of the ulnar side of the little finger.

Deep branch (r. profundus) The ulnar nerve initially accompanies the deep branch of the ulnar artery. This branch passes between the abductor digiti minimi muscle medially and the flexor digiti brevis muscle laterally. Then the deep branch deviates to the side, goes obliquely between the fascicles of the muscle that abducts the little finger, under the distal sections of the flexor tendons of the fingers, located on the interosseous palmaris muscles. The deep branch of the ulnar nerve innervates the flexor pollicis brevis, the abductor and opponensis muscles, the dorsal and palmar interosseous muscles, as well as the adductor pollicis muscle and the deep head of the flexor pollicis brevis muscle, the III and IV lumbrical muscles, bones, joints and ligaments of the hand. The deep palmar branch is connected by connecting branches to the branches of the median nerve. Median nerve(nervus medianus) departs from the medial and lateral bundles of the brachial plexus, covers the axillary artery with two bundles. On the shoulder, the median nerve initially passes in the same fascial sheath with the brachial artery, located lateral to it. The projection of the median nerve corresponds to the location of the medial groove of the shoulder. At this level, the median nerve often has a connecting branch with the musculocutaneous nerve. Further down, the median nerve first bends around the brachial artery from the outside, then at the level of the lower half of the shoulder it goes medial to the brachial artery and gradually moves away from it medially. At the level of the elbow bend, the median nerve is located at a distance of 1.0-1.5 cm medial to the brachial artery, then passes under the aponeurosis of the biceps brachii muscle and descends between the heads of the pronator teres. Then it moves down between the superficial and deep flexors of the fingers (Fig. 87). In the lower forearm, the median nerve is located between the flexor carpi radialis tendon medially and the palmaris longus muscle laterally. In the palm, the nerve passes through the carpal tunnel.

On the shoulder and in the ulnar fossa, the median nerve does not give branches. On the forearm, muscle branches extend from it to the pronator teres and quadratus, flexor digitorum superficialis, flexor pollicis longus, palmaris longus, flexor carpi radialis, flexor digitorum profundus (to the lateral part). The median nerve innervates all the muscles of the anterior forearm, except the medial part of the deep flexor digitorum and flexor carpi ulnaris. The nerve also gives off sensory branches to the elbow joint. Under the palmar aponeurosis, the median nerve is divided into terminal branches. A large branch arises from the median nerve anterior interosseous nerve (nervus interosseus anterior), which runs along the anterior surface of the interosseous membrane together with the anterior interosseous artery and innervates pronator quadratus, flexor pollicis longus, part of the flexor digitorum profundus and the radiocarpal joint. On the hand, the median nerve departs muscle branches, which innervate the muscles: short, abductor pollicis; short flexor pollicis (superficial head), opposable thumb, I and II lumbrical muscles. Palmar branch of the median nerve (ramus palmaris nervi mediani) penetrates the fascia of the forefoot and is directed further between the tendons of the flexor carpi radialis and the palmaris longus muscle. The palmar branch innervates the skin of the lateral half of the wrist and part of the skin of the eminence of the thumb. The terminal branches of the median nerve are three common palmar digital nerves (nn. digitales palmares communes), which are located under the superficial (arterial) palmar arch and palmar aponeurosis (Fig. 88). First common palmar digital nerve innervates the deep head of the flexor pollicis brevis, the first lumbrical muscle and gives off three cutaneous branches - own palmar digital nerves (nn. digitales palmares proprii). Two of them innervate the skin of the radial and ulnar sides of the thumb, the third - the skin of the radial side of the index finger. Second And third general

Rice. 87. The median nerve and other nerves on the anterior side of the left forearm, anterior view. The superficial flexor digitorum is cut off, its origin is turned to the medial side: 1 - median nerve; 2 - brachial artery; 3 - radial nerve; 4 - deep branch of the radial nerve; 5 - tendon of the biceps brachii; 6 - brachioradialis muscle; 7 - muscle - pronator teres (cut off and turned laterally); 8 - radial artery; 9 - superficial branch of the radial nerve; 10 - muscle - long flexor of the thumb; 11 - median nerve; 12 - tendon of the flexor carpi radialis muscle (cut off); 13 - superficial palmar branch of the radial artery; 14 - tendon of the superficial flexor digitorum muscle (cut off); 15 - tendon of the flexor carpi ulnaris muscle; 16 - dorsal branch of the ulnar nerve; 17 - muscle - flexor carpi ulnaris; 18 - muscle - deep flexor of the fingers; 19 - flexor pollicis ulnaris; 20 - ulnar artery; 21 - muscle - superficial flexor of the fingers (cut off and turned away); 22 - ulnar recurrent artery; 23 - medial epicondyle of the humerus; 24 - ulnar nerve Rice. 88. Nerves of the hand. Palmar side, front view: 1 - ulnar nerve; 2 - tendon retinaculum; 3 - muscle that abducts the little finger; 4 - muscle that flexes the little finger; 5 - common palmar digital nerves (from the ulnar nerve); 6 - muscle opposing the little finger; 7 - tendons of the muscles - long flexor fingers; 8 - own palmar digital nerves (from the ulnar nerve); 9 - own palmar digital nerves (from the median nerve); 10 - muscle that adducts the thumb (transverse head); 11 - common palmar digital nerves (from the median nerve); 12 - short muscle that flexes the thumb; 13 - short muscle, abductor pollicis; 14 - median nerve (palmar branch)

palmar digital nerves give two own palmar digital nerve (nn. digit t ales palm t ares pr t oprii), going to the skin of the sides of the II, III and IV fingers facing each other and to the skin of the back side of the distal phalanx of the II and III fingers. In addition, the median nerve innervates the elbow, wrist, wrist, and first four fingers. Musculocutaneous nerve(nervus musculocutaneus) originates from the lateral bundle of the brachial plexus in the axillary cavity. The nerve is directed laterally and downward, piercing the abdomen of the coracoid- brachialis muscle, is located between the posterior surface of the biceps brachii muscle, the anterior surface of the brachialis muscle and extends into the lateral ulnar groove. In the lower part of the shoulder, the nerve pierces the fascia and then exits on the lateral side of the forearm called lateral cutaneous nerve of the forearm (n t ervus cutan t eus antebr t achii later t alis). Muscular branches the musculocutaneous nerve innervates biceps muscle shoulder, coracobrachialis and brachialis muscles. Sensitive branch This nerve innervates the capsule of the elbow joint. The lateral cutaneous nerve of the forearm innervates the skin of the radial side of the forearm to the eminence of the thumb. Radial nerve(nervus radialis) starts from the posterior bundle of the brachial plexus at the level of the lower edge of the pectoralis minor muscle. Then it passes between the axillary artery and the subscapularis muscle and, together with the deep artery of the shoulder, goes into the brachiomuscular canal, goes around the humerus and leaves this canal in the lower third of the shoulder on its lateral side. After this, the nerve pierces the lateral intermuscular septum of the shoulder, running downward between the brachialis muscle and the beginning of the brachioradialis muscle (Fig. 89). At the level of the elbow joint, the radial nerve divides into superficial And deep branches. It departs from the radial nerve on its way to the axillary cavity posterior cutaneous nerve of the shoulder (n t ervus cutan t eus br t achii post t erior), which runs posteriorly, pierces the long head of the triceps brachii muscle, pierces the fascia near the deltoid tendon and branches in the skin of the posterior and posterolateral sides of the shoulder. Another nerve posterior cutaneous nerve of the forearm (n t ervus cutan t eus antebr t achii post t territory) arises from the radial nerve in the brachiomuscular canal. First, this branch accompanies the radial nerve, then just above the lateral epicondyle of the humerus it pierces the fascia of the shoulder. This nerve innervates the skin of the posterior aspect of the lower arm and forearm, as well as the capsule

Rice. 89. The radial nerve and its branches on the posterior side of the shoulder, posterior view. The lateral head of the triceps brachii muscle and the deltoid muscle are cut and turned to the sides: 1 - axillary nerve; 2 - teres major muscle; 3 - posterior circumflex artery of the humerus; 4 - triceps brachii muscle (long head); 5 - brachial artery; 6 - radial nerve; 7 - muscle branches; 8 - middle collateral artery; 9 - triceps brachii muscle (medial head); 10 - inferior ulnar collateral artery; 11 - ulnar nerve; 12 - lateral epicondyle; 13 - lateral cutaneous nerve of the forearm; 14 - posterior cutaneous nerve of the forearm; 15 - radial collateral artery; 16 - triceps brachii muscle (lateral head); 17 - deep artery of the shoulder; 18 - deltoid muscle of the shoulder joint. Muscular branches innervate the triceps brachii and olecranon muscles. Deep branch of the radial nerve (ramus profundus nervi radialis) from the anterior lateral radial groove it emerges into the thickness of the supinator, approaches the neck of the radius, goes around it and emerges on the back side of the forearm. This branch innervates the muscles of the posterior forearm: extensor carpi radialis longus, extensor carpi radialis brevis, supinator, extensor digitorum, extensor digitorum, extensor carpi ulnaris, abductor pollicis longus, extensor pollicis longus, extensor pollicis brevis. The deep branch continues into posterior interosseous nerve (n t ervus inter t osseus post t erior), which accompanies the posterior interosseous artery and innervates adjacent muscles. Superficial branch (ramus superficialis) exits the anterior side of the forearm, goes down, passes in the radial groove, located outward from the radial artery. In the lower third of the forearm, this branch passes to the dorsum between the brachioradialis muscle and the radius, pierces the fascia of the forearm and innervates the skin of the dorsum and lateral side of the base of the thumb (Fig. 90). The superficial branch is divided into five dorsal digital nerves(nervi digitales dorsales). Nerves I and II go to the radial and ulnar sides of the thumb and innervate the skin of its back side; III, IV, V nerves innervate the skin of the II and radial side of the III fingers at the level of the proximal (main) phalanx.

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Upper limb has innervation from roots C5-C8 with minor additions Th1 and C4. These roots form three bundles: lateral, posterior and medial. They go together in a plexus to the shoulder joint and are divided into two main trunks - the supraclavicular and subclavian parts.

Supraclavicular part of the brachial plexus

The supraclavicular part of the brachial plexus contains the following nerve branches: muscular branches, long thoracic nerve, pectoral nerves, dorsal scapular nerve, suprascapular nerve, thoracodorsal nerve, subclavian nerve and subscapular nerve.

Muscular branches supply the scalene muscles and the longus colli muscle.

Subclavian nerve (C5, C6), a very delicate nerve, innervates the subclavian muscle.

Long thoracic nerve (C5-C7) supplies the serratus anterior muscle. Failure of function is detected in the position (installation) of the scapula, when its medial edge lags behind the chest. In this case they speak of “wing-shaped blades”.

Thoracic nerves (C5-Th1) supply the pectoralis major and minor muscles.

Dorsal scapular nerve (C5) innervates both rhomboid muscles and partly the levator scapulae muscle. This muscle also has branches from the cervical plexus. The movement disorder is detected by testing the action of the muscle.

Suprascapular nerve (C4-C6).

It supplies the supraspinatus, abdominal muscles and partly the teres minor muscle. Isolated damage is very rare. Because of this, the resultant force during movement disturbances decreases slightly. The supraspinatus muscle abducts the arm and supports deltoid abduction as a tether muscle. The cavitary and teres minor muscles are involved in external rotation.

Supplies the latissimus dorsi and teres major muscles. It is best to determine their mild weakness with the patient lying on his stomach. He simultaneously raises both arms in internal rotation and resists back surface shoulders

supplies the subscapularis and teres major muscles. They show their weakness clinically only in internal rotation.

Infraclavicular part of the brachial plexus

Forms a node from which the nerves of the arm and hand emerge. These are the musculocutaneous nerve, axillary nerve, median nerve, ulnar nerve, radial nerve and sensory medial cutaneous nerve of the forearm and medial cutaneous nerve of the shoulder.

Musculocutaneous nerve (C4-C6) Innervates, together with the motor bundle, the biceps brachii muscle, the coracobrachialis muscle and the brachialis muscle. Failure of the brachialis and biceps brachii muscles is usually easy to identify.

Damage to the coracobrachialis muscle, which is involved in adduction and flexion of the shoulder joint, is difficult to fix. The nerve, after transmitting the motor branch, runs as the lateral cutaneous nerve of the forearm in the region of the forearm and supplies its radial region.

Axillary nerve (C5, C6) short and strong, supplies two motor muscles, namely the deltoid muscle and the teres minor muscle. You need to be able to determine mainly the failure of the deltoid muscle, while the failure of the teres minor muscle does not play a big role.

Its sensitive branch is considered the lateral cutaneous nerve. It innervates the lateral (side) side of the shoulder girdle and arm.

Median nerve (C6-Th1, sometimes also C5) is a very long nerve, its branch goes to the forearm and to the hand.

As a result (see Table 1.7), the median nerve innervates all the muscles of the inner surface of the forearm, with the exception of the flexor carpi ulnaris and the ulnar part of the deep flexor digitorum, subsequently all the thenar muscles, with the exception of the adductor pollicis muscle and the internal, deep horizontal head flexor pollicis brevis. It also innervates the first lumbrical muscles.

So, the median nerve innervates the following muscles: pronator teres, flexor radialis wrists, long palmaris muscle, flexor digitorum superficialis, flexor digitorum profundus (lateral head), flexor pollicis longus, pronator quadratus, abductor pollicis brevis, oppons pollicis brevis, flexor pollicis brevis (superficial head) and finally the 1st and 2nd lumbrical muscles.

Movement impairment when the median nerve is damaged necessarily occurs; a number of other movements will depend on the radial and ulnar nerves innervating the balancing muscles. Functional failure appears at first glance to be less significant based on the large area of innervation of these nerves.

Table 1.7. Median nerve (innervation of C6 roots

The entire median nerve can be examined clinically. Based on the signs and symptoms, a decision is made about his condition.

1. Hand position: due to intact extensor longus and the adductor (adductor muscle), it is possible to bring the 1st finger closer to the other fingers. In this case they talk about the “monkey's paw”.

2. Test isolated flexion the terminal phalanx of the index finger: the middle link is fixed in extension. With disorders of the median nerve, flexion of the terminal phalanx is impossible due to paralysis of the deep flexor digitorum.

3. Test of the 1st finger: the fingers of the hands move one towards the other, that is, the 1st finger towards the rest. There is no movement of the 1st finger on the paresis side.

4. Circular test: the tip of the 1st finger moves along the bodies of the metacarpal (metacarpal) bones. On the affected side, movement is not possible in full (up to the fifth metacarpal), but only for the first half, if the adductor pollicis muscle is preserved, movement is possible. The second part of the movement (opposition) is impossible to perform with the 1st finger.

5. Symptom of folded hands: the patient clenches his hands into a fist. On the side of the disorder, bending of the first three fingers is impossible; they remain straightened.

6. Opposition and abduction of the 1st finger is impossible.

7. Bottle sign: when grasping the bottle for more weak side paresis, slight pressure is exerted on it. A skin fold forms between the 1st and index fingers due to weak abduction and opposition of the 1st finger, i.e. the bottle is not held tightly.

8. Fist test: on the side of paralysis, the patient cannot clench a fist, since the flexion of the first three fingers is defective.

9. If the median nerve is damaged above the branching of a certain branch, it is also impossible for the pronator teres to perform pronation (inward rotation).

Sensitivity: in the area of the thenar and flexor surface of the 1st finger, in the middle part of the palm, in the 2nd, 3rd and part of the 4th fingers and, finally, on the dorsal side of the distal phalanges of the 2nd and 3rd fingers. In general, not a very wide sensitivity zone. Significant and frequent autonomic disorders and causalgia are observed.

Table 1.8. Ulnar nerve (innervation of C5 roots-Th1). Branch height for individual muscles

The ulnar nerve is a long and powerful nerve that receives fibers from the C5-Th1 roots. It gives off its first branch in the forearm, the main branching occurs only in the palm. Sensitive cutaneous branches supply the dorsal region and palmar side of the ulnar edge of the hand, the 5th finger and the ulnar half of the 4th finger. Inconsistently the entire 4th and ulnar side of the 3rd finger.

Motor fibers The ulnar nerve supplies mainly the minor muscles of the hand, with the exception of the opponensus muscles, the flexor pollicis brevis, the abductor pollicis muscle, and the 1st and 2nd lumbricals.

And so it innervates the following muscles: in the forearm, the flexor carpi ulnaris and the internal (medial) head of the deep flexor digitorum, in the hand, the adductor pollicis muscle, the interosseous muscles (palmar and dorsal), the 3rd and 4th lumbrical muscles, from the flexor brevis muscle the inner, deep horizontal head of the thumb, then the palmaris brevis, the abductor little finger muscle, the opponus little finger muscle and the flexor little finger brevis muscle.

Row clinical symptoms when testing for ulnar nerve disorders through which a conclusion can be made.

1. Hand position: the 1st finger is bent at the interphalangeal joint, the 4th and 5th fingers are extended at the metacarpophalangeal joints, and the other joints are bent. The 2nd and 3rd digits are less involved due to the well-preserved 2nd and 3rd lumbrical muscles. The little finger is secured with spacers due to the predominant activity of the extensor digitorum muscle. In this case, they talk about the claw-shaped position of the fingers.

2. Study of isolated adduction (adduction) and abduction (abduction) of the little finger. On the affected side, the patient cannot make these movements with the little finger.

3. Paper test (for the adductor of the 1st finger): the patient holds a sheet of paper between the 1st and index fingers and tries to stretch it in different directions. On the affected side, flexion in the distal phalanges of the fingers is impossible, so the paper will be grasped only in the healthy hand.

4. Drawing a Circle: When tested in isolated flexion, the major joints will maintain extension of the 2nd and 3rd fingers, while the 4th and 5th fingers will be flexed (3rd and 4th lumbricals paralysis)

5. When examining the mobility of the middle finger: on the affected side, lateral tilt of the middle finger is impossible.

Sensitivity manifests itself in the ulnar half of the dorsum of the hand, also in the hypotenera, in the little finger and the ulnar side of the 4th finger.

Radial nerve (C5-C6).

It gives off two sensory branches in the shoulder: the posterior cutaneous nerve of the shoulder and then distally the posterior cutaneous nerve of the forearm. After branching, the motor branch goes into the skin of the dorsum of the hand.

The radial nerve thus supplies sensory branches to the skin of the arm in a large area, namely the posterior cutaneous nerve of the shoulder, the dorsal region of the shoulder, the posterior cutaneous nerve of the forearm, and the dorsal region of the forearm. Two branches of nerves supply the radial half of the dorsum of the hand.

Table 1.9. Radial nerve (innervation of C5 roots-C8). Branch height for individual muscles

It supplies all the motor muscles of the dorsal side of the shoulder and the dorsal and radial side of the forearm. These are the triceps brachii, ulnaris, brachioradialis, extensor carpi radialis longus and brevis, supinator, extensor digitorum, extensor digitorum, extensor carpi ulnaris, longus muscle abductor pollicis, extensor pollicis longus and brevis, extensor of the index finger.

Symptoms of radial nerve damage.

1. Hand position: forearm pronated, bent at the wrist joint and proximal joints of the fingers, 1st finger down. When clinically observed, they speak of a fallen arm.

2. Finger folding test: the patient cannot fold the extended fingers because the hand is in palmar flexion.

3. Extensor Test: Extension of the arm and major finger joints is impossible. During testing, the fingers come to extension only at the interphalangeal joints due to the lumbrical muscles.

4. With injuries above the center of the shoulder (humerus), the brachioradialis muscle is also involved, flexion and supination are affected, in addition, the triceps brachii and olecranon muscles are affected, extension at the elbow is impaired.

Sensitivity is impaired from the site of injury.

Medial cutaneous nerve of the forearm is a long, thin nerve. It supplies the skin of the palmar and ulnar areas of the forearm with sensitive branches.

Medial cutaneous nerve of the shoulder- a thin nerve that innervates the skin of the ulnar side of the shoulder.