Axillary nerve palsy

Axillary Nerve Palsy is a neurological condition characterized by damage or injury to the axillary nerve, leading to weakness or paralysis of the deltoid muscle and, occasionally, the teres minor muscle. This condition can significantly impact the range of motion and functionality of the affected shoulder. The axillary nerve, a branch of the brachial plexus, plays a crucial role in the innervation of the shoulder muscles and the transmission of sensory information from the upper limb to the brain.

Causes

Axillary nerve palsy can result from various causes, including:

• Trauma: Direct injury to the shoulder area, such as fractures of the humerus or shoulder dislocation, can damage the axillary nerve.
• Surgical complications: Procedures involving the shoulder or upper arm may inadvertently affect the axillary nerve.
• Compression: Prolonged use of crutches or other devices that exert pressure on the axillary region can compress the nerve.
• Neuropathies: Certain systemic conditions, like diabetes mellitus, can predispose individuals to nerve damage, including the axillary nerve.

Symptoms

The primary symptom of axillary nerve palsy is weakness or paralysis of the deltoid muscle, leading to difficulty or inability to abduct the arm. Other symptoms may include:

• Numbness or sensory changes in the skin overlying the deltoid muscle.
• Muscle atrophy in chronic cases.
• Weakness in external rotation of the arm if the teres minor is affected.

Diagnosis

Diagnosis of axillary nerve palsy involves a combination of clinical examination and diagnostic tests, including:

• Physical examination: Assessing muscle strength, range of motion, and sensory changes.
• Electromyography (EMG) and Nerve conduction studies (NCS): These tests evaluate the electrical activity of muscles and the speed of nerve signal transmission, respectively, to confirm nerve damage.
• Imaging studies: MRI or Ultrasound can visualize the path and condition of the axillary nerve, as well as rule out other causes of shoulder dysfunction.

Treatment

Treatment of axillary nerve palsy aims to restore shoulder function and may include:

• Physical therapy: Exercises to maintain joint mobility and prevent muscle atrophy.
• Corticosteroid injections: To reduce inflammation and pain.
• Surgery: In cases of severe trauma or when conservative treatments fail, surgical intervention may be necessary to repair or decompress the axillary nerve.

Prognosis

The prognosis for axillary nerve palsy varies depending on the cause and severity of the nerve injury. Many patients experience significant improvement with appropriate treatment, although full recovery may take several months. Early intervention is crucial to optimize outcomes.

Prevention

Preventing axillary nerve palsy involves minimizing risk factors for nerve injury, such as using proper techniques during sports and physical activities, avoiding prolonged pressure on the shoulder area, and managing chronic conditions that may lead to neuropathy.