Axillary nerve dysfunction (AND) is a condition marked by a loss of movement or sensation in the shoulder area. It’s also known as neuropathy of the axillary nerve. Excessive stress or damage to the axillary nerve, which serves the deltoid muscles and skin of the shoulder, causes AND.
Problems with the nerve can occur in the myelin sheath, which covers and protects the nerve, or the central part of the nerve cell, called the axon.
Damage to these areas reduces or prevents the movement of impulses within the nerve.
AND can be due to:
- blunt trauma or excessive stress on the nerve over a long period
- 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 the normal range of motion, which can occur with a hyperextension injury to the shoulder
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 exercise or perform manual labor should be careful 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’re at a higher risk for AND as well as 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 have AND, you may:
- feel numbness or tingling in the shoulder region
- have weakness in the shoulders
- have problems with normal physical activities, such as lifting your arms above your head
- have difficulty lifting objects
Over time, your shoulder muscles may become smaller because they aren’t used regularly. This can be a particular problem for people who exercise with high resistance and heavy weights.
Your doctor will perform a physical exam and ask 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 about whether you used crutches or other support devices to see if certain stresses damaged the axillary nerve.
Your doctor might order nerve tests, such as electromyography (EMG), to learn more about the status of your axillary nerve. Some imaging tests, such as MRI, may also be necessary.
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’s putting pressure on the axillary nerve.
If you 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, effective treatment can cure AND. The outcome depends on 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 anti-inflammatory medications and physical therapy.