WHAT IS AXILLARY NERVE DYSFUNCTION?
Axillary nerve dysfunction is a condition that manifests as a loss of sensation or absence of movement in the shoulder region. It is also referred to as axillary nerve neuropathy. Axillary nerve dysfunction results when the axillary nerve is damaged or when it is extremely stressed. An axillary nerve provides sensation to the deltoid muscles and the skin over the shoulder.
The nerve damage may be in the myelin sheath which is the outer covering of the nerve, or it may be in the axon which is the central part of the nerve. When these nerve parts are damaged, there will be a reduction or a limitation of impulse movement within the nerve.
CAUSES OF AXILLARY NERVE DYSFUNCTION
Dysfunction of the axillary nerve can result due to the following:
- Blunt trauma to the nerve or prolonged stress on the nerve
- Pressure on the axillary nerve by other body structures or trapping of the axillary nerve by other body parts
- Penetrating trauma such as that from a gunshot wound or knife wound
- Surpassing the normal range of movement such as a hyperextension injury on the shoulder
Problems with the axillary nerve can be caused by exceeding a comfortable range of movement. It is therefore worthy of note that those who exercise or carry out manual labor should not stretch their muscles or limbs beyond their usual range of movement. The quadrilateral space, located at the shoulder joint has been recognized by doctors to be the primary zone of injury for AND.
RISK FACTORS FOR AXILLARY NERVE DYSFUNCTION
The likelihood of developing dysfunction of the axillary nerve increases in the following people or conditions:
- An athlete who engages in high-impact activities in the upper body
- Carrying out tasks repeatedly using the shoulder
- Presence of a certain type of bone fracture
- Wrong use of supportive equipment such as crutches
The following symptoms are seen in the dysfunction of the axillary nerve:
- Numbness or tingling sensation in the shoulder area
- Shoulder weakness
- Difficulty in carrying out normal physical activities such as lifting the arms above the head
- Difficulty in carrying objects
These symptoms do not allow the shoulder region to be used frequently and over time, the shoulder muscles get smaller because they are rarely used. This can pose a problem to those who exercise using heavy weights and at high resistance.
DIAGNOSIS OF AXILLARY NERVE DYSFUNCTION
The doctor will ask questions that will help to tell if you have a problem with your axillary nerve. A physical examination will be carried out. The doctor examines the upper body and may further test for the presence of pain or sensitivity by asking you to raise your arms. Questions asked may include previous trauma to the shoulder, deltoid muscle, or area around the axillary nerve? The doctor might also ask if there was any use of crutches or support devices, as these may trigger axillary nerve damage.
The doctor may request for some tests such as the electromyography (EMG) which gives an idea of the electrical activities in the muscles and tells more about the status of the axillary nerve. Imaging tests such as MRI may also be important.
TREATMENT OF AXILLARY NERVE DYSFUNCTION
For mild to moderate cases of AND, the doctor may recommend adjustment of daily routine or physical therapy. Certain exercises are directed at muscle groups to help with nerve damage and preserve nerve function. Anti-inflammatory drugs may also be prescribed to help relieve the swelling or inflammation that is exerting pressure on the axillary nerve.
Narcotics may be prescribed if the pain is severe. In certain cases, the doctor would advise on surgery to repair the surroundings of the axillary nerve.
LONG TERM OUTLOOK
Majority of cases are cured with adequate treatment. The outcome is dependent on the extent and nature of the primary injury. A nerve which has been trapped will lead to extreme pain and will need surgery too. Milder forms of AND due to prolonged stress may be responsive to physical therapy and anti-inflammatory medications.