Axillary nerve dysfunction
Neuropathy - axillary nerve
Axillary nerve dysfunction is nerve damage that leads to a loss of movement or sensation in the shoulder.
Causes
Axillary nerve dysfunction is a form of peripheral neuropathy . It occurs when there is damage to the axillary nerve. This is the nerve that helps control the deltoid muscles of the shoulder and the skin around it. A problem with just one nerve, such as the axillary nerve, is called mononeuropathy .
Peripheral neuropathy
Peripheral nerves carry information to and from the brain. They also carry signals to and from the spinal cord to the rest of the body. Peripheral n...
Mononeuropathy
Mononeuropathy is damage to a single nerve, which results in loss of movement, sensation, or other function of that nerve.
The usual causes are:
- Direct injury
- Long-term pressure on the nerve
- Pressure on the nerve from nearby body structures
- Shoulder injury
Entrapment creates pressure on the nerve where it passes through a narrow structure.
The damage can destroy the myelin sheath that covers the nerve or part of the nerve cell (the axon). Damage of either type reduces or prevents the movement of signals through the nerve.
Conditions that can lead to axillary nerve dysfunction include:
- Body-wide (systemic) disorders that cause nerve inflammation
- Deep infection
-
Fracture
of the upper arm bone (humerus)
Fracture
If more pressure is put on a bone than it can stand, it will split or break. A break of any size is called a fracture. If the broken bone punctures...
-
Pressure from casts or
splints
Splints
A splint is a device used for holding a part of the body stable to decrease pain and prevent further injury.
- Improper use of crutches
- Shoulder dislocation
In some cases, no cause can be found.
Symptoms
Symptoms may include any of the following:
-
Numbness
over part of the outer shoulder
Numbness
Numbness and tingling are abnormal sensations that can occur anywhere in your body, but they are often felt in your fingers, hands, feet, arms, or le...
- Shoulder weakness , especially when lifting the arm up and away from the body
Exams and Tests
Your health care provider will examine your neck, arm, and shoulder. Weakness of the shoulder can cause difficulty moving your arm.
The deltoid muscle of the shoulder may show signs of muscle atrophy .
Muscle atrophy
Muscle atrophy is the wasting or loss of muscle tissue.
Tests that may be used to check axillary nerve dysfunction include:
-
EMG
and nerve conduction tests, will be normal right after the injury and should be done several weeks after the injury or symptoms start
EMG
Electromyography (EMG) is a test that checks the health of the muscles and the nerves that control the muscles.
-
MRI
or x-rays of the shoulder
MRI
A magnetic resonance imaging (MRI) scan is an imaging test that uses powerful magnets and radio waves to create pictures of the body. It does not us...
Treatment
Depending on the cause of the nerve disorder, some people do not need treatment. The problem gets better on its own. The rate of recovery can be different for everyone. It can take many months to recover.
Anti-inflammatory medicines may be given if you have:
- Sudden symptoms
- Small changes in sensation or movement
- No history of injury to the area
- No signs of nerve damage
These medicines reduce swelling and pressure on the nerve. They may be injected directly into the area or taken by mouth.
Other medicines include:
- Over-the-counter pain medicines may be helpful for mild pain (neuralgia).
- Other medicines may reduce stabbing pain.
- Opiate pain relievers may be needed to control severe pain.
If your symptoms continue or get worse, you may need surgery. If a trapped nerve is causing your symptoms, surgery to release the nerve may help you feel better.
Physical therapy can help maintain muscle strength. Job changes, muscle retraining, or other forms of therapy may be recommended.
Outlook (Prognosis)
It may be possible to make a full recovery if the cause of the axillary nerve dysfunction can be identified and successfully treated.
Possible Complications
Complications may include:
-
Deformity of the arm, shoulder
contracture
, or frozen shoulder
Contracture
A contracture develops when the normally stretchy (elastic) tissues are replaced by nonstretchy (inelastic) fiber-like tissue. This tissue makes it ...
-
Partial
loss of sensation
in the arm (uncommon)
Loss of sensation
Numbness and tingling are abnormal sensations that can occur anywhere in your body, but they are often felt in your fingers, hands, feet, arms, or le...
-
Partial shoulder
paralysis
Paralysis
Muscle function loss is when a muscle does not work or move normally. The medical term for complete loss of muscle function is paralysis.
- Repeated injury to the arm
When to Contact a Medical Professional
Call for an appointment with your health care provider if you have symptoms of axillary nerve dysfunction. Early diagnosis and treatment increase the chance of controlling symptoms.
Prevention
Preventive measures vary, depending on the cause. Avoid putting pressure on the underarm area for long periods. Make sure casts, splints , and other appliances fit properly. When you use crutches, learn how to avoid putting pressure on the underarm.
Splints
A splint is a device used for holding a part of the body stable to decrease pain and prevent further injury.
References
Steinmann SP, Spinner RJ. Nerve problems about the shoulder. In: Rockwood CA, Matsen FA III, Wirth MA, et al., eds. The Shoulder . 3rd ed. Philadelphia, PA: Elsevier Saunders; 2009:chap 27.
Taylor KF. Nerve entrapment. In: In: Miller MD, Thompson SR, eds. DeLee and Drez's Orthopaedic Sports Medicine: Principles and Practice. 4th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 58.
-
Damaged axillary nerve - illustration
Conditions associated with axillary nerve dysfunction include fracture of the humerus (upper arm bone), pressure from casts or splints, and improper use of crutches. Other causes include systemic disorders that cause neuritis (inflammation of nerves). If the cause of the axillary nerve dysfunction can be identified and successfully treated, there is a possibility of full recovery. The extent of disability varies. The worst problem most often is shoulder weakness.
Damaged axillary nerve
illustration
-
Damaged axillary nerve - illustration
Conditions associated with axillary nerve dysfunction include fracture of the humerus (upper arm bone), pressure from casts or splints, and improper use of crutches. Other causes include systemic disorders that cause neuritis (inflammation of nerves). If the cause of the axillary nerve dysfunction can be identified and successfully treated, there is a possibility of full recovery. The extent of disability varies. The worst problem most often is shoulder weakness.
Damaged axillary nerve
illustration
Review Date: 2/3/2015
Reviewed By: Amit M. Shelat, DO, FACP, Attending Neurologist and Assistant Professor of Clinical Neurology, SUNY Stony Brook, School of Medicine, Stony Brook, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.