Brachial plexus injury

Introduction to brachial plexus injury Brachialplexus is a common type of peripheral nerve injury characterized by pain, weakness, and muscle atrophy dominated by the scapular muscle. Brachial plexus injury is also seen in the shoulder and neck bullets, shrapnel wounds and other firearms penetrating or blind tube injuries, knife stab wounds, glass cutting injuries, drug damage and surgical accidental injuries, etc., such damage is more limited, but the degree of damage More serious, mostly nerve root rupture, may be associated with subclavian, sacral vein and other injuries, clavicular fracture, anterior shoulder dislocation, cervical rib, anterior scalene syndrome, primary or metastasis to the vicinity of the brachial plexus Tumors can also compress and damage the brachial plexus. basic knowledge The proportion of the disease: the incidence of the disease in car accident patients is about 5% Susceptible people: no specific people Mode of infection: non-infectious complication:

Cause of brachial plexus injury

(1) Causes of the disease

Brachial plexus injury is mostly

1 traction injury: the upper limb was wounded by a belt.

2 pairs of bruises: if hit by a fast car hitting the shoulder or shoulder by a flying stone.

3 cutting injury or gunshot wound.

4 crush injury: such as clavicle fracture or shoulder lock is squeezed.

5 birth injury: abnormal fetal position during childbirth or traction during labor.

(two) pathogenesis

The most common cause and pathological mechanism of brachial plexus injury is traction injury. Most of the adult brachial plexus injury (about 80%) is secondary to motorcycle or car accidents, such as motorcycles colliding with cars, motorcycles hit the roadside. Obstacle or big tree, the driver is injured and fell to the ground, the head and shoulders hit the obstacle or the ground, the head and shoulders are separated, the brachial plexus is subjected to excessive traction, the nerve is concussed, temporary sexual dysfunction, heavy The axons of the nerves are broken, and the roots of the nerve roots are broken. The heaviest ones can cause the five nerve roots to break from the spinal cord. It is like a "radish" avulsion and completely loses function (Fig. 2). After being caught by a machine, belt or conveyor belt, pulling out due to the instinctive reflection of the human body can cause damage to the brachial plexus, causing damage to the upper trunk when wound up, and causing damage to the whole brachial plexus when the horizontal direction is involved, and the collapse or height of the mine Heavy objects fall, crushed on the shoulders, shoulders impacted at high speeds, etc. can also damage the brachial plexus. Neonatal brachial plexus injury is seen when the mother is difficult to produce, the baby generally weighs more than 4kg, the head is exposed first, the first child is attracted. Or With forceps, causing the baby's head and shoulders separated and pulled over brachial plexus injury, mostly incomplete injury.

Brachial plexus injury is also seen in the shoulder and neck bullets, shrapnel wounds and other firearms penetrating or blind tube injuries, knife stab wounds, glass cutting injuries, drug damage and surgical accidental injuries, etc., such damage is more limited, but the degree of damage More serious, mostly nerve root rupture, may be associated with subclavian, sacral vein and other injuries, clavicular fracture, anterior shoulder dislocation, cervical rib, anterior scalene syndrome, primary or metastasis to the vicinity of the brachial plexus Tumors can also compress and damage the brachial plexus.

Brachial plexus injury prevention

1. Correct estimation of fetal weight

When the fetal head diameter is large, it is necessary to measure the shoulder diameter and the chest circumference, and it should be alert to the occurrence of shoulder dystocia. Pregnant women with diabetes, pregnant women with tall, expired births, who have given birth to a large child should be vigilant. It is estimated that the weight of non-diabetic pregnant women is 4500g, and the weight of pregnant women with diabetes 4000g should be cesarean section. Therefore, the fetal weight should be estimated as accurately as possible before delivery, and the mode of delivery should be carefully selected when considering a huge child.

2. Close observation of labor

Gestational diabetes has a small head and shoulder width, which is easy to cause shoulder dystocia, non-large head basin is not called, pelvic inlet is flat, the first stage of labor and the second stage of labor are prolonged, especially when the second stage of labor is prolonged or the first part of the lower part is blocked. The incidence of shoulder dystocia increased. For the second stage of labor extension, the first drop is blocked or slow, especially the prenatal estimated fetal weight > 4000g, should be alert to shoulder dystocia, should be relaxed cesarean section indications.

3. Correct handling of shoulder dystocia

Once a shoulder dystocia occurs, it should be treated immediately to prevent severe asphyxia and death in the newborn. Regular side cuts increase the space for fetal delivery.

Brachial plexus injury complications Complication

No special complications.

Brachial plexus injury symptoms Common symptoms Moro response retardation Muscle atrophy Brachial plexus involvement sensory disorder Elbow joints can not flex the upper limbs with palsy paralysis Fingers can not bend the nerve root injury

It is generally divided into upper brachial plexus injury (Erb injury), lower brachial plexus injury (Klumpke injury) and total brachial plexus injury. In 1985, Leffert made the following classification according to the mechanism of the brachial plexus injury and the injury site:

1. Open brachial plexus injury.

2. Closed (pull) brachial plexus injury

(1) Upper cranial plexus injury:

1 ganglion above brachial plexus injury (pre-ganglionic injury).

2 brachial plexus injury below the ganglia (post-ganglionic injury).

(2) Injury of the lower clavicle of the clavicle.

3. Radioactive brachial plexus injury.

4. Calving.

Brachial plexus injury examination

1. Electrophysiological examination Electromyography (EMG) and nerve conduction velocity (NCV) have important reference value for the degree of nerve injury and injury. Generally, it is examined 3 weeks after injury, sensory nerve action potential (SNAP) and Somatosensory evoked potential (SEP) contributes to the identification of preganglionic lesions, and SNAP is normal during preganglionic injury (the reason is that the posterior root sensory nerve cells are located outside the spinal cord, and the injury happens just in the proximal or preganglionic, sensation Nerve without Waller degeneration can induce SNAP), SEP disappears; SNAP and SEP disappear after post-segment injury.

2. Imaging examination of brachial plexus root avulsion, CTM (myelography plus computed tomography) can show contrast agent extravasation into the surrounding tissue space, dural sac tear, meningocele, spinal cord displacement, etc. (Fig. 3) In general, most of the meningocele means tearing of the nerve roots, or although the nerve roots are partially continuous, the internal damage is already serious and has continued to a very close plane, often prompting There is enough strength to cause arachnoid tears. Similarly, MRI (magnetic resonance imaging) can show the combined meningocele, cerebrospinal fluid leakage, spinal cord hemorrhage, edema, in addition to the nerve root tear. Etc. Hematoma is high on both T1WI and T2WI. Cerebrospinal fluid and edema are high on T2WI, while low on T1WI. MRI water imaging is more clear on the subarachnoid and cerebrospinal fluid. Time water (cerebrospinal fluid) is high signal, while other tissue structures are low signal.

Diagnosis and diagnosis of brachial plexus injury

The diagnosis of brachial plexus injury, including clinical, electrophysiological and imaging diagnosis, for the brachial plexus injury requiring surgical exploration, but also to make intraoperative diagnosis, according to the unique symptoms, signs, traumatic history, anatomical relationship of different nerve branch injuries And special inspection, you can determine the injured nerve and its damage plane, the degree of damage, the brachial plexus damage diagnosis steps are as follows.

1. To determine the presence or absence of brachial plexus injury, the presence of brachial plexus injury should be considered when:

(1) Joint injury of any 2 of the upper limb 5 nerves (, musculo, median, iliac crest, ruler) (non-identical cutting injury).

(2) Any of the 3 nerves (median, sacral, ulnar) of the hand is associated with dysfunction of the shoulder joint or elbow joint (passive activity is normal).

(3) Any of the 3 nerves in the hand (median, sacral, ulnar) combined with medial cutaneous nerve injury of the forearm (non-cutting injury).

2. Determine the brachial plexus injury site clinically with the pectoralis major muscle clavicle representing the neck 5,6 latissimus dorsi representing the neck 7, pectoralis major muscle chest rib representing the neck 8 chest 1, the above muscle atrophy indicates damage on the collarbone, ie root The cadre injury, the presence of the above-mentioned muscle function indicates that the injury is under the clavicle, that is, the bundle branch injury, which is an important basis for identifying the damage above and below the clavicle.

3. Positioning diagnosis

(1) Brachial plexus root injury:

1 Upper brachial plexus (neck 5 ~ 7) injury: sputum, musculocutaneous, scapular sacral: scapular scapular nerve paralysis, sputum, median nerve part paralysis, shoulder joint can not be abducted and lifted, elbow joint can not flex, wrist joint Although the flexion and extension but the muscle strength is weakened, the forearm rotation is also impeded, the finger movement is normal, the upper extremity stretches most of the loss, the deltoid muscle, the upper and lower muscles, the levator scapula, the large and small rhomboid muscle, the radial flexor digitorum, pronation Round or partial spasm of the round muscle, diaphragm, and supinator muscle.

2 lower brachial plexus (neck 8 chest 1) injury: ulnar nerve paralysis, medial cutaneous nerve of the arm, medial cutaneous nerve of the forearm, median, paralysis of the phrenic nerve, loss of function or serious obstacles in the hand, shoulder, elbow, wrist The activity is still good, the Horner sign often appears on the affected side, the muscles in the hand are all atrophied, the interosseous muscle is especially obvious, the fingers can not flex or stretch or have serious obstacles, the thumb can not be abducted, the forearm and the ulnar side of the hand are missing, the ulnar wrist The flexor muscle refers to the deep and shallow flexor muscles, the large and small muscle groups, all the sacral muscles and the interosseous muscles appear sputum, while the triceps muscles and the forearm extensors are partially paralyzed.

3 total brachial plexus injury: early all the upper limbs are delayed paralysis, each joint can not actively move, but the passive movement is normal, because the trapezius muscle is dominated by the accessory nerve, the shrug movement can exist, the upper limb feels the inner side of the arm due to the intercostal arm nerve from The second nerve is still present, the rest are all lost, the upper extremity tendon reflexes disappear, the temperature is slightly lower, the distal part of the limb is swollen, the Horner sign is positive, the late upper extremity muscle is significantly atrophied, and the joints are often restricted by passive movement due to contracture of the joint capsule. Especially with severe shoulder and knuckles.

(2) brachial plexus injury:

1 Upper dry injury: its clinical symptoms and signs are similar to the upper brachial plexus root injury.

2 dry injury: independent injury is rare, but can be seen in the correction of the nerve neck 7 nerve root displacement repair when the neck 7 nerve root or the middle stem is cut, only the middle finger refers to the abdominal numbness, the muscle strength of the extensor muscle group is weakened, etc. It can be gradually restored after 2 weeks.

3 dry injury: its clinical symptoms and signs and lower brachial plexus root injury are similar.

(3) brachial plexus injury:

1 lateral beam injury: musculocutaneous, medial nerve lateral root and anterior lateral nerve palsy, elbow joint can not bend, or although it can be flexed (recurrent muscle compensation) but biceps palsy, forearm can be pre-rotating but pronation Muscle paralysis, wrist joint flexion but radial wrist flexor paralysis, other joint activities of the upper limbs are normal, forearm lateral sensation loss, biceps brachii, radial flexor digitorum, pronator and pectoralis major The movement of the clavicle, the shoulder joint and the joints of the hand are normal.

2 medial bundle injury: ulnar, medial root of median nerve and anterior medial nerve palsy, internal muscles of the hand and forearm flexor muscles, the fingers can not flex and stretch, the thumb can not be abducted, can not be on the palm, on the finger, the hand has no function The inner side of the upper limb and the ulnar side of the hand disappeared. The hand was flat and claw-shaped, and the shoulder and elbow joints were normal. The medial bundle injury and the neck 8 chest 1 nerve root injury were similar, but the latter often had the Horner sign. The triceps, part of the forearm extensor muscles.

3 posterior bundle injury: sputum, sputum, chest and back, scapular nerve paralysis, deltoid muscle, small round muscle, extensor muscle group, latissimus dorsi, subscapularis muscle, large round muscle spasm, shoulder joint can not be abducted, upper arm can not be rotated The elbow and wrist joints cannot be stretched back, the metacarpophalangeal joints cannot be straightened, the thumb cannot be straightened and the temporal side abduction, the lateral side of the shoulder, the back of the forearm and the dorsal side of the back of the hand are dysfunctional or lost.

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