What Is a Brachial Plexus Birth Injury?

Brachial plexus nerves are composed of cervical C5-8 and T1 nerve roots. The branches are mainly distributed in the upper limbs, and some small branches are distributed in the upper pectoralis muscles, superficial back muscles, and deep cervical muscles. , Axillary nerve, musculocutaneous nerve, median nerve, radial nerve, ulnar nerve. Brachial plexus nerves dominate the senses and movements of the upper limbs, shoulders, and chest. Brachial plexus injury is a type of peripheral nerve injury caused by work injury, traffic accident, or birth injury. After the injury, the patient's upper limb function was partially or completely lost, leaving him with a lifetime disability.

Basic Information

English name

brachial plexus injury

Visiting department

neurosurgery

Common locations

Upper limb

Common causes

Work injury, traffic accident, birth injury

Common symptoms

Partial or complete loss of upper limb function

Causes of Brachial Plexus Injury

Stretch injury

Such as the upper limbs were wounded by the leash and injured.

Collision injury

Such as being struck by a fast car or injured by a flying stone.

3. Cut wound or bullet wound

4. crush injury

If the clavicle is fractured or the acromioclavicular area is squeezed.

5. Birth injury

Abnormal fetal position during delivery or traumatic injury during delivery.

Brachial plexus injury classification

Generally divided into upper brachial plexus injury, lower brachial plexus injury and full brachial plexus injury. The following classifications are based on the mechanism and location of brachial plexus injury:

Open brachial plexus injury

2. Closed (pulled) brachial plexus injury

( 1) Upper clavicle plexus injury Brachial plexus injury above ganglion (pre-ganglion injury); Brachial plexus injury below ganglion (post-ganglion injury).

(2) Infraclavicular brachial plexus injury

3. Radiation brachial plexus injury

4. Paralysis

Clinical manifestations of brachial plexus injury

Brachial plexus nerve root injury

(1) The nerve roots of the upper brachial plexus (necks 5 to 7) are injured , and paralysis of the axillary, musculocutaneous, superior scapular and dorsal scapular nerves, and partial paralysis of the radial and median nerves. The shoulder joint cannot be abducted and lifted, the elbow joint cannot be flexed, the wrist joint can be flexed and stretched but the muscle strength is weakened, the forearm rotation is also impaired, the finger movement is normal, and most of the upper limb extension is missing. The deltoid muscle, superior and inferior muscles, scapular levator muscle, large and small rhomboid muscles, radial wrist flexor muscles, pronation round muscles, radial brachialis muscles, and supinator muscles are paralyzed or partially paralyzed.

(2) Injury of the lower brachial plexus nerve root (neck 8 chest 1) ulnar nerve palsy, medial arm cutaneous nerve, medial forearm cutaneous nerve damage, partial medial and radial nerve paralysis. Loss of hand function or severe obstacles, shoulder, elbow, and wrist movements are good, and Horner sign often appears on the affected side. All the internal muscles of the hand are atrophied, the interosseous muscles are particularly obvious, the fingers cannot be flexed or stretched, or there is a serious obstacle, the thumb cannot be abducted on the palm side, and the skin of the forearm and the ulnar side of the hand is missing. Paralysis of the ulnar carpi flexor muscles, the deep and shallow flexor muscles, the large and small intermuscular muscle groups, all vermiform and interosseous muscles. The triceps and forearm extensors were partially paralyzed.

(3) In the early stage of the whole brachial plexus injury, the entire upper limb showed retarded paralysis, and the joints could not actively move, but the passive movement was normal. Since the trapezius is innervated by the accessory nerve, shrugging movements may exist. Except for the existence of the intercostal arm nerves from the second interstitial nerve, the rest of the upper limbs were all lost. All upper tendon reflexes disappeared, the temperature was slightly lower, and the distal limbs were swollen. Horner sign is positive. The late upper limb muscles are significantly atrophied, and the joints often have passive movement restrictions due to joint capsule contractures, especially the shoulder and finger joints.

2. Brachial plexus neural trunk injury

(1) The clinical symptoms of upper stem injuries are similar to the signs and injuries of the upper brachial plexus.

(2) Independent injury of the middle trunk is rarely seen, but it can be seen when the repair of the cervical 7 nerve root or the middle trunk is cut off on the healthy neck. Only shows, numbness of the middle finger, abdominal muscle weakness, etc., can gradually recover after 2 weeks.

(3) The clinical symptoms of the lower trunk injury are similar to the signs and injury of the lower brachial plexus root.

3. Brachial plexus injury

(1) Injury of the lateral musculature, lateral root of the median nerve, and parathoracic nerve. The elbow joint cannot be flexed, or although it can flex (radio brachialis compensatory), but the biceps is paralyzed; the forearm can be pronated but the pronated round muscle is paralyzed, the wrist can be flexed but the radial wrist flexor is paralyzed, and other joints of the upper limbs Activity is still normal. Loss of sensation in the radial forearm. The biceps brachii, radial wrist flexor, pronator round muscle, and pectoralis major clavicle were paralyzed, and the movements of the shoulder and hand joints were normal.

(2) Injury of medial bundle ulnar, medial root of median nerve, and parathoracic nerve. The internal muscles of the hand and the forearm flexor muscles are all paralyzed, the fingers cannot be flexed and extended (the metacarpophalangeal joints can be straightened), the thumb cannot be abducted on the palm side, and the palms and fingers cannot be functional. Feeling disappeared on the inside of the forearm and the ulnar side of the hand. Hands are deformed with flat hands and claw-shaped hands. Shoulder and elbow joints function normally. Medial bundle injury is similar to cervical 8 chest 1 nerve root injury, but the latter often has paralysis of the pectoralis major (thoracic ribs), triceps, and forearm extensors, but the former does not have this phenomenon.

(3) Posterior tract injury: The subscapularis and great round muscles innervated by the subscapular nerve; the latissimus dorsi muscles innervated by the thoracic and dorsal nerves; the deltoid muscles and small round muscles innervated by the axillary nerves; the upper and forearm extensor muscles innervated by the radial nerves are paralyzed. The shoulder joint cannot be abducted, the upper arm cannot be turned inward, the elbow and wrist joint cannot be extended back, the metacarpophalangeal joint cannot be straightened, the thumb cannot be straightened and radial abduction, the sensory disturbances on the lateral shoulder, the back of the forearm and the radial half of the back of the hand or Lost.

Brachial plexus injury examination

Neurophysiological examination

Electromyography (EMG) and nerve conduction velocity (NCV) have important reference value for the presence or absence of nerve injury and the extent of the injury. Generally, examination is performed 3 weeks after injury. It is helpful for the identification of pre-ganglion and post-ganglion injury. SNAP is normal during pre-ganglion injury (the reason is that the posterior root sensory nerve cell body is located outside the spinal cord, and the injury happens to be near the pre-ganglion, and the sensory nerve has no Wallerian degeneration. Can induce SNAP), SEP disappears; both SNAP and SEP disappear when post-node injury.

2. Imaging examination

In brachial plexus avulsion, myelography and computerized tomography (CTM) can show extravasation of contrast medium into the surrounding tissue space, tearing of the dural sac, spinal meningocele, and spinal cord displacement. Generally speaking, Spinal meningocele mostly means tearing of the nerve root, or although the nerve root has some continuity, the internal damage has been serious and has continued to a very near plane, often suggesting that there is enough force to cause the arachnoid Tear, likewise, magnetic resonance imaging (MRI) can show tears in the nerve root, and also show coexisting meningocele, cerebrospinal fluid leakage, spinal cord hemorrhage, edema, etc. Hematomas on both T1WI and T2WI For high signal, cerebrospinal fluid and edema show high signal on T2WI and low signal on T1WI. MRI hydrography technology is more clear to show the leakage of subarachnoid space and cerebrospinal fluid. At this time, water (cerebrospinal fluid) showed high signal. All other organizational structures are low signal.

Brachial plexus injury diagnosis

The diagnosis of brachial plexus injury includes clinical, electrophysiological, and imaging diagnosis. For brachial plexus injury that requires surgical exploration, an intraoperative diagnosis must also be made. According to the unique symptoms and signs of different nerve branch injuries, combined with the history of trauma, anatomical relations and special examinations, the injured nerve, its level of injury, and the degree of injury can be determined. The diagnostic procedure for brachial plexus injury is as follows.

1. Determine whether brachial plexus injury

The presence of brachial plexus injury should be considered in the following cases: any 2 joint injuries in the 5 nerves of the upper limbs (axillary, musculocutaneous, median, radial, and ulnar) (non-planar cut injuries); 3 nerves in the hand (Mid, radial, and ulnar) any one with shoulder or elbow dysfunction (passive movement is normal); Any one of the 3 nerves in the hand (median, radial, and ulnar) with medial forearm cutaneous nerve injury (non-cutting) hurt).

2. Identify the brachial plexus injury site

Clinically, the pectoralis major clavicle represents necks 5 and 6, the latissimus dorsi muscle represents neck 7, and the pectoralis major muscle rib represents neck 8 and chest 1. Atrophy of the clavicle of the pectoralis major muscle, suggesting damage to the upper trunk or neck, 5 or 6; atrophy of the latissimus dorsi, suggesting damage to the middle trunk or cervical nerve root; atrophy of the pectoralis major muscle ribs, suggesting damage to the lower trunk or neck, chest 1

Brachial plexus injury treatment

General treatment

For common traction brachial plexus injuries, conservative treatment is the main method in the early stage, that is, neurotrophic drugs (vitamin B ₁ , vitamin B ₆ , vitamin B _12, etc.) are applied, and the injured part is subjected to physical therapy, such as electrical stimulation therapy, infrared, magnetic In the treatment of the affected limb, functional exercises are performed to prevent contracture of the joint capsule, and it can be combined with acupuncture, massage, and massage, which is conducive to the elimination of neural concussion, loosening of neural adhesion and joint relaxation. The observation period is generally about 3 months.

2. Surgical treatment

(1) Indications for surgery Brachial plexus nerve open injury, cutting injury, gunshot wound, surgical injury and drug-induced injury should be detected early and surgically repaired. Brachial plexus nerve injury, traction injury, crush injury, such as an absent pre-segmental injury should be treated as early as possible, for closed post-segmental injury, can be treated conservatively for 3 months. Surgical exploration can be considered in the following cases: those who have no significant recovery in function after conservative treatment; those who have skipped function recovery, such as shoulder function that has not recovered, but elbow function recovered first; during the process of functional recovery, no interruption for 3 months Progresser. In the case of childbirth injury, surgical exploration can be performed if there is no obvious functional recovery or only partial recovery of function in the first six months after birth.

(2) Surgical methods: Brachial plexus exploration: superior clavicle plexus nerve exploration; lower clavicle plexus nerve exploration; clavicle plexus nerve exploration.

(3) Surgery principles According to the findings during surgery, the processing principles are as follows: neurolysis; nerve transplantation; nerve displacement.