Axillary nerve dysfunction (AND) or injury is also called neuropathy of the axillary nerve. It describes a loss of movement or lack of sensation in the shoulder area of the body. Stress or damage to the axillary nerve, which serves the deltoid muscles and skin of the shoulder, causes this dysfunction.
Problems with the nerve can occur in two places:
- the myelin sheath, which covers and protects the nerve
- the central part of the nerve cell, called the axon
Damage to these areas reduces or prevents the movement of impulses within the nerve.
The following can cause AND:
- blunt trauma or excessive stress on the nerve over a long period of time
- other body structures putting pressure on the axillary nerve, or trapping it against another body part
- a penetrating injury, such as a knife or gunshot wound
- exceeding a normal range of motion
Stressing the limb by going beyond a comfortable range of motion can trigger problems with the axillary nerve and other nerves. This is why experts always warn that those who work out or perform manual labor to take care not to stretch muscles and limbs beyond their usual range of motion. Some doctors refer to the primary zone of injury for AND as the quadrilateral space, which is part of the shoulder joint.
You are at a higher risk for AND and related nerve damage if you:
- are an athlete or someone who participates in high-impact upper body activities
- perform repetitive tasks using your shoulder
- have a certain type of existing bone fracture
- improperly use supportive equipment such as crutches
If you are suffering from AND, you may feel numbness or tingling in the shoulder region. You may experience weakness in the shoulders and have problems with normal physical activities, such as lifting your arms above your head. Difficulty lifting objects can also be a sign of AND.
Over time, your shoulder muscles may become smaller because they cannot be worked out regularly. This can be a particular problem for individuals who typically work out with high resistance and heavy weights.
Your doctor will do a physical exam and ask you questions to determine if you have a problem with your axillary nerve. He or she will test your upper body for pain and sensitivity by having you raise your arms. Your doctor may also ask about any prior damage to the shoulder, the deltoid muscles, or anything else in the area of the axillary nerve. Your doctor might also ask in-depth questions about whether you have used crutches or other support devices to see if certain stresses may have damaged the axillary nerve.
Your doctor might order nerve tests, such as electromyography (EMG), to learn more about the integrity of your axillary nerve. Some radiology tests, such as magnetic resonance imaging (MRI), may also be needed.
For moderate cases of AND, your doctor may recommend physical therapy or changes to your daily routine. Specific exercises can help muscle groups deal with nerve damage and preserve nerve function. Your doctor may also prescribe anti-inflammatory medications to combat swelling or inflammation that is putting pressure on the axillary nerve.
In your have severe pain, your doctor might prescribe narcotic medication. In some cases, your doctor may suggest surgery to repair areas around the axillary nerve.
In many cases, AND can be solved by effective treatment. The outcome has to do with the extent and nature of the initial injury. A trapped nerve can cause chronic pain and require surgery. Lesser types of AND caused by long-term stress may respond well to medications and physical therapy.