Axillary nerve as the name suggests is the nerve in axilla region. It is a major peripheral nerve of the upper limb originating from the roots of C5 and C6 spinal roots. Damage or injury to this nerve causes axillary nerve dysfunction. Injury to axillary nerve leads to loss of movement and sensation in the upper arm and shoulder.
The primary role of axillary nerve is to control the movement of deltoid muscle and provide sensation to the skin of upper arm and shoulder. Injury to this nerve thus impairs both motor as well as sensory functions of the shoulder and upper arm.
There are many causes for axillary nerve disorder; treatment depends on the underlying cause. In most cases of axillary nerve dysfunction recovery is satisfactory if the cause is known and corrected.
Causes Of Axillary Nerve Damage
Axillary nerve dysfunction can develop if the myelin sheath covering the nerve or the nerve cells is damaged. As a result it prevents flow of messages between the nerve cells. Here are the following causes which can give rise to axillary nerve dysfunction.
- Compression of the axillary nerve from the structures adjacent to it.
- Entrapment of the nerve within its nearby structures.
- Direct trauma to the nerve from a knife or a sharp object penetrating in the axillary area.
- A blunt trauma.
- Shoulder injury.
- Stretching the arm beyond its normal range of motion. Especially it is the cause among weight lifters and manual laborers who tend to stretch their arm repetitively while working.
- Fracture of arm bone.
- People who walk with the help of crutches often suffer from this condition with its improper use.
- Deep seated infection in the upper arm.
- Dislocation of shoulder joint.
Symptoms Of Axillary Nerve Dysfunction
Axillary nerve dysfunction gives rise to certain noticeable symptoms. It affects motor as well as sensory functions.
- Feeling of pins and needles in the shoulder and upper arm, especially on the skin over the inferior area of the deltoid muscle. It is also called regimental badge area.
- Loss of sensation in the area below the deltoid muscle as the nerve innervates this area.
- Weakness in shoulder. Patient experiences difficulty in upward movement of arm or stretching the arm away from the body. Difficulty in lifting any object due to weakness in the muscles of arm.
- The deltoid muscle atrophies and loses its strength due to restriction in physical activity with the affected hand.
Diagnosis Of Axillary Nerve Injury
Axillary nerve dysfunction is diagnosed by a health care practitioner. During physical examination, he will examine the shoulder, neck and arm area to determine if the symptoms are related to axillary nerve dysfunction.
He will also see the proper movement of arm, if the patient is able to raise his arm or experiences difficulty in lifting it due to weakness. He will also inquire for the symptoms such as loss of sensation in the deltoid region, tingling numbness past history of trauma or use of crutches.
Certain tests such as EMG (electromyelogram) will detect conduction deficit which certainly helps in diagnosis of particular nerve dysfunction, in this case axillary nerve dysfunction.
Axillary Nerve Dysfunction Treatment
Axillary nerve dysfunction is successfully treated in most cases. The primary aim of treatment is to preserve and re-instate the lost strength of arm and shoulder. Treatment may depend on the underlying cause and its severity. Recovery also depends whether the condition is chronic or since short period.
In mild to moderate cases axillary nerve dysfunction recovery is possible with physical therapy or change in lifestyle and physical work. The physiotherapist may recommend specific set of exercises which help in strengthening the deltoid muscle.
Sometimes anti inflammatory medicines are used to reduce inflammation which may be compressing the nerve. If the pain is severe painkiller medicines may be recommended by the physician.
In few incurable cases, surgery may be recommended to reduce pressure caused by inflamed tissues that surround and press the nerve.