Median nerve injury

Introduction to median nerve injury The median nerve consists of fibers from the neck 5-8 and the thoracic 1 nerve root. The lateral root separated from the lateral branch of the brachial plexus, and the medial root separated from the medial cord, together form the median nerve, the median nerve innervates most of the muscles of the flexor of the forearm, and most of the muscles in the lateral half of the hand And the palm of your hand rubs the skin feeling. Median nerve injury is more common. A small number of cases were injured at the same time as the ulnar nerve. basic knowledge The proportion of sickness: 0.01% Susceptible people: no specific population Mode of infection: non-infectious Complications: joint pain, joint sprain

Cause of median nerve injury

Ischemic contracture (20%):

Ischemic contracture is also often associated with median nerve injury. Ischemic contracture, also known as chronic congestive ischemic contracture, is the ultimate destination of most cardiovascular diseases and the leading cause of death. There is no exact statistics on morbidity and mortality. In 1996, the American Society of Contractures had 4.9 million ischemic contractures in the United States; 1% of patients with ischemic contractures in adults aged 50-60 years; and 10% in elderly people over 80 years of age. .

Crush injury (15%):

Previous arm fractures or scar contractures were common, often with severe extensive soft tissue injury. The strength of scar contracture is large, and the strength of contracture is increasing during the healing of scars with extensive tissue defects. Before the early trauma does not heal, the movement and shape of the limbs can be almost normal; once healed, the contraction strength increases, the light is only the skin and subcutaneous soft tissue contracture, and the severe ones can cause muscles, tendons, blood vessels, nerves to shrink, and even bone. Joint deformity, many years of contracture, can cause limb distortion and serpentine deformity, completely losing work function.

Pull injury (30%):

Most common, most of which is caused by the arm being caught in the machine.

Cut injury (15%):

Glass cuts that occur during daily life or work, or accidental injuries during forearm surgery.

Gunshot wound or drug mis-injection into the nerve trunk (5%):

Gunshot wounds or drug mis-injection into the nerve trunk caused damage compared to the above-mentioned injuries, and there were fewer cases of these two types of injuries.

Median nerve injury occurs more frequently, and the injury site is mostly in the wrist or forearm, and the injured in the upper arm or ankle is smaller.

Median nerve injury prevention

It is necessary to pay attention to the application of the brace to make the affected joint in the functional position. Since the median nerve injury not only affects the flexion and flexion of the flexor and palm, but also the physical loss of the opponent's function has a great influence, it is an important task to restore the sensory function. Feeling diminished allows the patient to touch various objects of different shapes, sizes, textures, such as flannel, coins, keys, etc., first under direct vision, and then practice when closing the eyes, so that the patient can gradually identify different objects, Sensitization, need to use desensitization treatment, that is, to educate patients to use sensitive areas, self-massage in sensitive areas, stimulate sensitive areas with different materials, educate patients to protect the sensory area, do not use the hand to touch dangerous objects To prevent burns, stab wounds, and pressure ulcers, when the finger muscle strength returns to level 3, the patient should be instructed to do more manual exercises and ADL exercises.

Median nerve injury complications Complications, joint pain, joint sprain

The median nerve has no branches on the elbow, and its damage can be divided into high-level injury (upper elbow) and low-level injury (wrist). The inter-muscular and sacral muscle paralysis and the hand-feeling disorder dominated by the wrist injury. The clinical manifestations are mainly the thumb-to-palm dysfunction and the sacral semi-sensory disturbance of the hand, especially the food, the middle finger and the distal sensation disappear, and the forearm muscles that are dominated by the elbow injury are paralyzed. In addition to the above performance, there is also a thumb. Healing, middle finger flexion dysfunction, if the treatment is not timely, can cause nerves, excessive adhesion of tendons and muscle atrophy and joint stiffness.

Symptoms of median nerve injury Common symptoms Thumb and index finger can not... Write or take small items difficult nerve stem break can not stretch the thumb open injury interosseous muscle and intermuscular muscle atrophy forearm pronation deformity index finger feel disappear nerve fiber nerve damage Nerve bundle damage

(1) Median nerve injury in the wrist

1. Exercise: The three intermuscular muscles are the thumb-to-occipital muscles, the short abductor muscles and the short flexors of the buckling short flexors. Therefore, the thumb cannot be on the palm and cannot form a 90° forward and palm plane. Fingertips, large fish atrophy, thumb adduction form a metacarpal deformity, and the short flexor hallucis muscle is sometimes supplied to the abnormal ulnar nerve.

2. Feeling: Loss of hand sensation is most affected by median nerve injury. After the injury, the thumb, the food, the middle finger, the half palm face of the ring finger and the back of the corresponding finger are lost, which seriously affects the function of the hand. The object is easy to fall, has no physical sense, and is vulnerable to trauma and burns.

3. Nutritional changes: Finger skin and nails have significant nutritional changes, the phalanx atrophy, and the fingertips become smaller and sharper.

(B) the median nerve injury of the elbow

1. Exercise: In addition to the above, there are also the anterior circumflex muscle, the radial flexor digitorum, the anterior flexor muscle, the long palm muscle, the superficial flexor muscle, the deep flexor tendon and the flexor hallucis longus, so the thumb The index finger can not flex, the two fingers are still straight when the fist is clenched, some of the middle finger can bend a part, the index finger and the middle finger metacarpophalangeal joint can partially flex, but the interphalangeal joint is still straight.

2. Sensory and nutritional changes are more common with anterior median nerve injury combined with burning neuralgia.

Median nerve injury examination

No relevant laboratory tests, the diagnosis of this disease is mainly based on its clinical manifestations and medical history, auxiliary examinations are less used, mainly for some routine physical examinations, such as electromyography to help determine whether there is nerve damage and degree .

The examination of the median nerve and the performance of the sacral nerve are as follows:

(1) (2) Thumb abduction is normal to the palm.

(3) (4) The thumb cannot be on the palm after the median nerve injury in the elbow, and the thumb, food, and middle finger cannot flex.

(5) (6) The zone of feeling fading or disappearing.

Diagnosis and diagnosis of median nerve injury

Mainly based on its clinical manifestations and medical history, auxiliary examinations are less used. Mainly to carry out some regular physical inspections. For example, EMG can help to determine whether there is nerve damage and degree. Physical examination refers to electrocardiogram, electroencephalogram, X-ray, gastroscope, bronchoscopy, CT, etc., in which CT and other examinations have differences in various parts, such as CT, spine CT and so on.

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