Injuries to the arms, forearms or wrists can cause various neurological disorders. One such disorder is the median nerve palsy . The median nerve controls most of the muscles in the forearm. It controls the kidnapping of the thumb, the flexion of the hand on the wrist, the flexion of the radius of the digital radius, is the sensory nerve for the first three fingers, etc. Because of the main role of this median nerve, it is also called the hand eye. If the median nerve is damaged, the ability to kidnap and oppose the thumb can be lost due to the paralysis of the famous muscles. Various other symptoms can occur that can be corrected through surgery and transfer of the tendon. Transfer of the tendon has been highly successful in restoring motor function and improving functional outcomes in patients with median nerve palsy.
Video Median nerve palsy
Signs and symptoms
- Lack of ability to kidnap and oppose the thumb due to paralysis of the famous muscles. This is called "ape deformity".
- Sensory loss in the thumb, forefinger, index finger, and radial aspect of the ring finger
- Weakness in pronation of the forearm and flexibility of hands and fingers
- Daily living activities such as brushing, tying shoes, making phone calls, turning knobs and writing, may become difficult with median nerve injuries.
Maps Median nerve palsy
Cause
Paralysis of the median nerve is often caused by a penetrating injury to the arm, forearm, or wrist. Can also occur from blunt trauma or neuropathy.
Median nerve paralysis can be divided into 2 sub-categories - high and low medianus nerve palsy. High MNPs involve lesions in the elbows and forearms areas. Median nerve palsy is low due to lesions in the wrist. Compression at different median nerve levels produces symptoms and/or syndrome variables. These areas are:
- Under the Struthers ligament
- Passes bicipital aponeurosis (also known as lacertus fibrosus)
- Between two terraced pronator heads
- The compression in the carpal tunnel causes the carpal tunnel syndrome
Anatomy
The median nerve receives fibers from roots C6, C7, C8, T1 and sometimes C5. It is formed in the axilla by the branches of the medial and lateral chord of the brachial plexus, which are on both sides of the axillary artery and joined together to create the anterior nerve to the artery.
The median nerve is closely related to the brachial artery in the arm. The nerve enters the medial cussa medial into the brachial tendon and passes between the two heads of the pronator teres. Then remove the anterior interosseus branch in the pronator teres.
The nerve continues down the forearm between the flexor digitorum profundus and the superficial flexor digitorum. The median nerve appears to lie between the superficial flexor digitorum and the muscular flexor carpi ulnar right above the wrist. In this position, the nerves emit a palmar skin branch that supplies the skin of the middle of the palm.
The nerve continues through the carpal tunnel into the hand, lying in the anterior carpal tunnel and lateral tendons of the superficialis flexor digitorum. Once in hand, the nerve is divided into branches of muscle and palmar digital branch. The muscular branch supplies high eminates while the palmar digital branch supplies the sensation to the palmar aspect of the lateral 3 ½ digit and two lateral lumbrains.
Diagnosis
Because lesions to different areas of the median nerve produce the same symptoms, doctors perform complete motor and sensory diagnosis along the neural pathways. Decreased values ​​of neural conduction studies are used as indicators of nerve compression and may be helpful in determining the localization of compression.
Palpation over the elbow joint may reveal bony consistency. Radiographic images may indicate the growth of abnormal bone spurs (a supracondyloid process) only proximal to the elbow joint. The embedded fibrous tissue (ligamentum struthers) can suppress the median nerve as it passes through the process. This is also known as supracondylar process syndrome. Compression at this point can also occur without bone spurs; in this case, the aponeurotic tissue found in the location where the Struthers ligaments should be responsible for compression.
If the patient mentions symptomatic reproduction to the forearm during elbow flexion 120-130 degrees with the forearm at maximum supination, then the lesion can be localized to the area below lacertus fibrosus (also known as bicipital aponeurosis). It is sometimes misdiagnosed as an elbow strain and a medial or lateral epicondyle.
The lesion to the upper arm area, only proximal to where the motor branch from the forearm of the derived flexor, is diagnosed if the patient is unable to make a fist. More specifically, the patient index and middle finger can not flex on the MCP joint, while the thumb is usually unable to resist. This is known as a blessing arm or hand thanks to the Pope. Another test is a bottle mark - patients can not close all their fingers around a cylindrical object.
Carpal tunnel syndrome (CTS) is caused by compression of the median nerve as it passes through the carpal tunnel. The nerve conduction velocity test by hand is used to diagnose CTS. Physical diagnostic tests include Phalen maneuver or Phalen test and Tinel sign. To ease the symptoms, the patient can describe a movement similar to "shake the thermometer", another indication of CTS.
The pronator teres syndrome (also known as pronator syndrome) is a median nerve compression between two pronator teres muscle heads. The Pronator Teres test is an indication of the syndrome - patients report pain when trying to pronate the forearm against resistance while extending the elbow simultaneously. The doctor may notice the enlarged pelvic pronator muscle. Tinel sign area around head pronator teres should be positive. The key to distinguishing this syndrome from carpal tunnel syndrome is the absence of pain during sleep. The newer literature collectively diagnoses the median nerve paralysis that occurs from the elbow to the forearm as the pronator teres syndrome.
In uncooperative patients, skin wrinkle tests offer a pain-free way to identify denatures of the fingers. After soaking in water for 5 minutes, the normal fingers will become wrinkled, while the shallow fingers will not.
In "Deformity of the ape's hand", the muscles of fame become paralyzed by a collision and then flattened. This hand deformity is not by itself an individual diagnosis; it is seen only after the famous muscles have stopped growing. While adductor pollicis remains intact, smoothing the muscles causes the thumb to become stirred and laterally rotated. The conflicting enemy causes the thumb to flex and rotate toward the medial, making the thumb unable to resist. Carpal tunnel syndrome can lead to later muscle paralysis that can cause hand-disfiguring apes if left untreated. Ape hand disabilities can also be seen in the hands of benediction deformities.
The Anterior Interosseal Nerve (AIN), the median nerve branch, only explains the movement of the fingers in the hand and has no sensory ability. Therefore, AIN syndrome is pure neuropathic. NSAID is considered a very rare condition because it accounts for less than 1% neuropathy in the upper extremities. Patients suffering from this syndrome have distal interphalangeal joint disorders, because they can not pinch anything or make and "OK" sign with their index finger and thumb. This syndrome can occur from a pinched nerve, or even an elbow dislocation.
Prevention
One way to prevent this injury from happening is to be informed and educated about the risks involved in hurting your wrist and hand. If the patient is suffering from median nerve paralysis, occupational therapy or wearing a splint can help reduce pain and further damage. Using a dynamic splint, which pulls the thumb into opposition, will help prevent excessive abnormalities. This splint can also help function and help the fingers flex to the thumb. Stretching and use of C-splint can also help prevent further damage and deformities. Both of these methods can help in the level of movement that the thumb can have. While it is not possible to prevent trauma to your arms and wrists, patients can reduce the amount of compression by maintaining proper shape during repetitive activity. Furthermore, strengthening and increased flexibility reduce the risk of nerve compression.
Treatment
Depending on the severity of the lesion, the doctor may recommend conservative or surgical treatment. The first step is to just rest and modify the daily activities that aggravate the symptoms. Patients may be prescribed anti-inflammatory drugs, physical or occupational therapy, splints for elbows and wrists, and corticosteroid injections as well. This is the most common treatment for CTS. Especially that involving compression on the wrist, as in CTS, it is possible to recover without treatment. Physical therapy can help build muscle strength and braces or splints help to restore. In pronator teres syndrome, in particular, immobilization of elbow and mobility exercises in the free range of pain is initially determined. However, if the patient is not relieved of symptoms after 2 to 3 months of normal refractory period, then decompression surgery may be necessary. Surgery involves shortening tissue or removing bone parts that compress the nerves.
Many tendon transfers have been shown to restore opposition to the thumb and provide flexion of the fingers and thumb. To obtain optimal results, individuals need to follow the principles of tendon transfer: normal tissue balance, movable joints, and wound-free beds. If these requirements are met then certain factors need to be considered such as matching lost muscle mass, fiber length, and cross-sectional area and then selecting muscle-tendon units of the same size, strength, and potential of sightseeing.
For patients with low median nerve paralysis, it has been shown that the flexor digitorum of the superficial fingers and the radius or extensor of the wrist is closest to the force and movement required to restore full oppo and thumb strength. This type of transfer is the preferred method for median nerve palsy when strength and movement are required. In situations where only thumb mobility is desired, extensor indicis proprius is the ideal transfer.
For high median nerve paralysis, brachioradial or extensor transfer of radialis longus carpi is more appropriate to restore lost thumb flexion and side-to-side transfer of the flexor digitorum profundus of the index finger is generally sufficient. To restore the independent flexion the index finger can be performed by using a teron pronator or extensor unit of the carpi radialis ulnar tendon. All of the mentioned transfers are generally quite successful because they incorporate appropriate course of action, the location of the pulley, and the insertion of the tendon.
Rehabilitation
In patients with high median nerve palsies, recovery times vary from four months to 2.5 years. Initially, the patient was immobilized in the neutral position of the forearm and the elbow flexed at 90 ° to prevent further injury. In addition, gentle exercises and soft tissue massage are applied. The next goal is reinforcement and flexibility, usually involving wrist extension and flexion; However, it is important not to overuse the muscles to prevent back injury. If surgery is necessary, postoperative therapy initially involves decreased pain and sensitivity to the incision area. Adequate grip and elbow strength should be achieved before returning to pre-operative activity.
Epidemiology
- The amount of discharges associated with a median nerve injury decreased from 3,402 in 1993 to 2,737 in 2006.
- Average hospital costs in nominal dollars increased from $ 9,257 to $ 27,962 between 1993 and 2006.
- 37.1% of patients in 2006 with median nerve injury required acute improvement.
- The median nerve injury was the most likely to be treated in the emergency room of all peripheral nerve injuries (68.89% of the median nerve, 71.3% of the ulnar nerve and 77.06% in the radial nerve).
- The highest percentage of patients who came out with a median nerve injury in 2006 was between the ages of 18-44.
- Of all patients in 2006 who suffered a median nerve injury, 77.76% were male and 21.75% were female.
See also
- Peripheral nerve injury
- Peripheral neuropathy
References
External links
Source of the article : Wikipedia
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