Intrafascicular nerve fiber damage

Introduction III degree nerve injury, that is, nerve fiber damage in the nerve bundle, including axons, myelin sheath and endometrium, but the nerve bundle membrane is intact. Because of the formation of scar tissue in the endometrium, some of the regenerated fibers cannot cross the distal end of the scar and cannot be completely regenerated. The degree of functional recovery is mainly related to the scar in the intima and the movement of the intraductal membrane and the distribution of sensory fibers. 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. Often caused by traction, crush injury, and cutting injury.

Cause

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.

1. Pulling injuries: The most common. Most of it is caused by the arm being caught in the machine.

2. Crush injury: The previous arm fracture or scar contracture is the main, often accompanied by severe extensive soft tissue injury.

3. Cut injury: Glass cuts that occur in daily life or work, or accidental injuries during forearm surgery.

4. Gunshot wounds or mis-injection of drugs into the nerve trunk: In comparison with the above-mentioned injuries, there are fewer cases of these two types of injuries.

5. Ischemic contracture is also often associated with median nerve injury.

an examination

Related inspection

F-wave electromyography

The diagnosis of this disease is mainly based on its clinical manifestations and medical history, and the auxiliary examination is less used. Mainly to carry out some regular physical inspections. For example, EMG can help to determine whether there is nerve damage and degree.

Differential diagnosis

1I degree nerve damage, that is, nerve loss. Axonal continuity exists but conduction is interrupted, the change in conduction block is reversible, and recovery is fast and complete.

2 II degree nerve injury, that is, axonal interruption. Axons and myelin damage, but endometrial tissue is not damaged. The Waller's degeneration occurs in the distal segment below the injury site, and the function is fully recoverable.

3III degree nerve injury, that is, nerve fiber damage in the nerve bundle, including axons, myelin sheath and endometrium, but the nerve bundle membrane is intact. Because of the formation of scar tissue in the endometrium, some of the regenerated fibers cannot cross the distal end of the scar and cannot be completely regenerated. The degree of functional recovery is mainly related to the scar in the intima and the movement of the intraductal membrane and the distribution of sensory fibers.

4IV degree nerve injury, that is, nerve bundle injury and rupture, including axon, endoneurium, and nerve bundle membrane, only the outer membrane of the nerve is intact, and the continuity of nerve trunk is maintained only by the outer membrane of the nerve. Scars in the nerve can completely block the regenerative nerve from reaching the target organ. If surgery is not taken, the motor and sensory functions cannot be restored.

5V degree nerve injury, that is, nerve stem rupture, nerve bundle and nerve epithelium are broken, nerve trunk completely destroyed, and continuity is lost. This type of injury is the most serious type of injury and is usually present in open injuries.

The diagnosis of this disease is mainly based on its clinical manifestations and medical history, and the auxiliary examination is less used. Mainly to carry out some regular physical inspections. For example, EMG can help to determine whether there is nerve damage and degree.

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