Peripheral nerve injury

Introduction to peripheral nerve injury Peripheral nerve refers to all nerves except the brain and spinal cord, including ganglia, nerve trunk, nerve plexus and nerve ending devices; peripheral nerves can be divided into brain nerves connected to the brain and connected to the spinal cord according to the parts connected to the central nervous system. Spinal nerves. Peripheral nerve damage is mainly caused by trauma, birth injury, bone dysplasia, lead and alcoholism, etc., which cause disturbances, dyskinesia and nutritional disorders. Peripheral nerves are nerves other than the central nervous system (brain and spinal cord). It includes 12 pairs of cranial nerves, 31 pairs of spinal nerves and vegetative nerves (sympathetic, parasympathetic). basic knowledge Sickness ratio: 0.05% Susceptible people: no specific population Mode of infection: non-infectious Complications: muscle atrophy

Causes of peripheral nerve injury

The causes of peripheral nerve injury can be divided into:

1. Pulling the injury, such as birth trauma, caused by brachial plexus injury.

2. Cutting injuries, such as knife cuts, chainsaw injuries, glass cuts, etc.

3. Compression injury, such as fracture and dislocation caused by nerve compression.

4. Firearm injuries, such as gunshot wounds and shrapnel injuries.

5. Ischemic injury, limb ischemic contracture, nerves are also damaged.

6. Electric burns and radioactive burns.

7. Drug injection injury and other iatrogenic injuries.

Peripheral nerve injury prevention

1. Prevent excessive thinking and pay attention to the combination of work and rest, because excessive thinking can cause brain damage, and the body's immunity can be reduced over time;

2, psychological counseling under the guidance of Chinese medicine practitioners, because psychological stability, for the recovery and health care of nervous system diseases, can also practice yoga empathy.

Peripheral nerve injury complications Complications muscle atrophy

Peripheral nerve damage can cause severe physical dysfunction and even leave a lifelong disability.

Peripheral nerve injury symptoms Common symptoms Respiratory reflex disappeared Sensory hypersensitivity Sensory disorder Muscle atrophy Hypoxic ischemic nerve injury Muscle tone reduction

There are many types of peripheral nerve damage. The following are several common peripheral nerve injuries.

1. Brachial plexus injury :

Mainly manifested as the movement of the nerve root type, sensory disturbance, the upper part of the brachial plexus is characterized by the sagging of the upper limb, the adduction of the upper arm, the abduction of the external rotation, the forearm adduction and extension, the pronation of the fore and the rotation, the shoulder, the upper arm There is a long and narrow sensory dysfunction area on the outside of the forearm. The lower part of the brachial plexus is characterized by atrophy of the small muscles of the hand and a claw shape. There is a sensory loss on the ulnar side of the hand and the inside of the forearm, and sometimes Horner's syndrome occurs.

2. sacral nerve injury : dyskinesia, shoulder abduction amplitude is reduced, deltoid muscle skin dysfunction, angular muscle atrophy, shoulder loss of round bulge appearance, shoulder peaks, forming a "square shoulder."

3. Musculoskeletal nerve injury : After the musculocutaneous nerve is emitted from the lateral bundle, it obliquely penetrates the diaphragm, descends between the biceps and diaphragm, and branches to support the above three muscles. The final branch is slightly above the elbow. On the lateral side, the deep fascia of the arm was removed, and it was renamed as the lateral cutaneous nerve of the forearm. It was distributed on the lateral skin of the forearm. After the musculocutaneous nerve was injured, the biceps, the diaphragm and the lateral skin of the forearm were sensory.

4. Median nerve injury : first, second, three-finger flexion loss; thumb-to-palm movement loss; large fish muscle atrophy, palmar deformity; index finger, middle finger distal section feeling disappeared.

5 sacral nerve injury : sacral nerve injury is the most vulnerable of the whole body nerves, often complicated by the middle part of the humerus fracture, mainly manifested as the disappearance of the wrist force, and the "drift wrist" is a typical disease; the thumb abduction and the finger extension Disappeared; the back of the hand, the feeling between the two metacarpals disappeared completely.

6. Ulnar nerve injury : The distal end of the fourth and fifth fingers cannot be flexed; the interosseous tendon, the finger abduction and abduction function is lost; the small fish atrophy is flattened; the little finger feels completely disappeared.

7. Femoral nerve injury: dyskinesia, anterior femoral muscle spasm, difficulty in lifting the leg while walking, can not stretch the calf, sensory disturbance, skin sensation in front of the femoral and calf inner side, quadriceps atrophy, humerus protrusion, knee reflex disappear .

8. Sciatic nerve injury: When the sciatic nerve is completely injured, the clinical manifestations are similar to those of the sacral nerve joint injury. The ankle joint and the toe joint have no voluntary activity, the foot is drooping and the horseshoe-like deformity, and the ankle joint can swing with the movement of the affected limb. Exercise, calf muscle atrophy, Achilles tendon reflex disappears, knee flexion is weak, knee extension is normal, calf skin feels except for the medial side, often due to compression of the nerves of the nerve and only manifested as sensory loss, when the sciatic nerve is partially injured, the two heads The muscles are often paralyzed, while the semitendinosus and semimembranosus are rarely involved. In addition, the calves or soles are often accompanied by jumping pain, numbness or burning.

9 total nerve injury : foot deformity, the patient in order to prevent the toe from dragging on the ground, walking high foot, walking across the gait; foot and toe can not stretch, can not be outreached; foot and small toe anterolateral Feeling lost.

Peripheral nerve injury examination

According to the history of trauma, clinical symptoms and examination, determine the location, nature and extent of nerve damage.

First, clinical examination

1. The wound is inspected for wounds. If there is a wound, the extent and depth of the wound should be checked, the soft tissue injury and the presence or absence of infection, the path of the bullet wound or shrapnel, the presence or absence of vascular injury, fracture or dislocation, etc. The wound has healed, and the condition of the scar and the presence or absence of an aneurysm or arteriovenous fistula are observed.

2. Limb posture to observe whether the limb is deformed, sacral nerve injury has carpal sag; ulnar nerve injury has claw-like hand, that is, the 4th and 5th fingers of the metacarpophalangeal joint are overextended, the interphalangeal joint is flexed; the median nerve injury has a pickpocket; The total nerve injury of the sputum has a foot drop, etc. If the time is too long, due to the imbalance of the muscles, joint contractures may occur.

3. Examination of motor function The nerve damage and its degree are judged according to the condition of muscle spasm, and the muscle strength is distinguished by a six-stage method.

Level 0 - no muscle contraction;

Level 1 - muscle contraction slightly;

Level 2 - does not counter the direction of gravity, can achieve full joint mobility;

Level 3 - Against the direction of gravity, can achieve full joint motion, but can not add any resistance;

Level 4 - against the direction of gravity and a certain resistance, can achieve full joint movement;

Level 5 - normal.

Peripheral nerve damage causes muscle spasm, loss of tension, progressive muscle atrophy, depending on the degree of nerve damage, muscle strength has the above difference, muscle atrophy gradually disappears during nerve recovery, such as continuous exercise can have continuous progress.

4. Examination of sensory function Check pain, touch, temperature, two points of difference and its range of changes, determine the degree of nerve damage, generally check the pain and touch, pay attention to the sensory supply area for a single nerve or other nerve supply overlap, Compared with the healthy side skin, the physical sense and the shallow touch are fine feelings, and the pain and deep touch are rough feelings. After the nerve repair, the rough feeling is restored earlier.

Sensory dysfunction can also be distinguished by a six-level method:

Level 0 - no feeling at all;

Level 1 - deep painful presence;

Level 2 - painful and partial touch;

Level 3 - complete sense of pain and touch;

Level 4 - pain, complete touch, and two points of difference, but the distance is larger;

Level 5 - feels completely normal.

5. Nutritional changes After nerve injury, the skin in the dominating area is chilly, sweat-free, smooth, atrophic, sciatic nerve injury often occurs in the foot pressure sore, foot frostbite, no sweat or less sweat area generally meets the range of feeling disappearance, can sweat Tests, commonly used methods are (1) iodine-starch test: apply 2% iodine solution on the palm side of the finger, apply a layer of starch after drying, then bake it with a lamp, or drink it with hot water to make the patient sweat and sweat. After changing to blue, (2) Ninhydrin fingerprint test; press the finger or toe on a clean sheet of paper (can also press after the hot drink), draw the finger toe range with a pencil, then Put into 1% ninhydrin solution, if there is sweat, it can show dot-like fingerprints on the fingerprints, soaked and fixed with nitric acid solution, which can be stored for a long time. Because sweat contains various amino acids, it turns purple after encountering ninhydrin. Neurological recovery can be observed by multiple examinations and comparisons.

6. Reflection According to the condition of muscle spasm, the tendon reflex disappears or decreases.

7. There are pseudo-neuromas in the proximal end of the nerve, often with severe pain and tenderness, and the tenderness is released to the innervation area.

8. Dry slamming test (Tinel sign) After nerve injury or damaged nerve repair, in the injury plane or the site where nerve growth is reached, the nerve is gently stunned, that is, the nerve distribution area is radioactive numbness, which is called Tinel sign positive. .

Second, electrophysiological examination

Through the electromyography and evoked potential examination, the extent, extent, recovery and prognosis of the nerve injury were determined.

Diagnosis and diagnosis of peripheral nerve injury

Diagnosis: According to clinical manifestations, examination can be diagnosed.

Differential diagnosis: mainly differentiated from central nervous system injury.

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