Shoulder and Elbow cases axillary neuropathy

A 47-year-old, right-hand-dominant male presents to your clinic complaining of right shoulder weakness for the past 2 months. He denies any history of trauma but notes sudden onset of pain 2 months ago that lasted approximately 2 weeks and then subsided without any intervention and was followed by shoulder weakness. He works as a lawyer and has been going through a divorce for the past year. Physical examination reveals no tenderness to palpation about the shoulder. He has decreased sensation over the lateral aspect of the shoulder, decreased muscle bulk over the left shoulder compared with the contralateral side, and weakness with left shoulder abduction. He is distally neurovascularly intact. The patient had already been referred for an x-ray and MRI by his primary care doctor that are shown in Figures 2–62 and 2–63.

 

 

 

Figure 2–62

 

 

 

Figure 2–63

 

Injury to what structure is most likely responsible for his symptoms?

1. Suprascapular nerve

2. Dorsal scapular nerve

3. Axillary nerve

4. Posterior cord of the brachial plexus

 

Discussion

The correct answer is (C). The patient’s decreased sensation over the deltoid, deltoid muscle atrophy on examination, and MRI with atrophy of the teres minor points to axillary nerve dysfunction. Suprascapular nerve injury (Choice A) would result in atrophy of the infraspinatus and or infraspinatus muscles, leading to weakness with external rotation and/or forward flexion. Dorsal scapular nerve injury (Choice B) would result in weakness of the rhomboid muscles and levator scapulae. While injury to the posterior cord of the brachial plexus (Choice D) would result in symptoms of axillary nerve palsy, they would also involve dysfunction of the radial nerve, which also comes off the posterior cord.

What is the most likely etiology of this patient’s nerve dysfunction?

1. Quadrilateral space syndrome

2. Parsonage Turner syndrome

3. Mass effect

4. Blunt trauma

Discussion

The correct answer is (B). Parsonage Turner syndrome (brachial neuritis) is characterized by acute brachial neuropathy which can affect different nerves of the brachial plexus. In this patient, it is the most likely explanation for his atraumatic deltoid paralysis with axillary nerve palsy in a time of severe stress. The cause of Parsonage Turner Syndrome is unknown, but it has been associated with severe stress and viral infection. Quadrilateral space syndrome (Choice A) involves entrapment of the axillary nerve as it passes through the quadrilateral space, would present as chronic dull pain, and is usually not associated with decreased sensation. While Choices C and D can both be a cause of axillary nerve injury, the patient has no history of trauma and there are no masses on his MRI.

You send the patient for an EMG which shows decreased conduction through the axillary nerve and denervation of the deltoid and teres minor muscles.

What is the most appropriate management for the patient at this time?

1. Physical therapy

2. Corticosteroid injection into the subacromial space

3. Operative exploration of the axillary nerve

4. Referral to neurology for further workup

 

Discussion

The correct answer is (A). Physical therapy focusing on passive- and active-assisted range of motion is the cornerstone of management of Parsonage Turner syndrome. Corticosteroid injection into the subacromial space (Choice B) will not help with his decreased range of motion and weakness. Choice C would be appropriate if the patient’s axillary nerve injury was traumatic, with operative nerve exploration occurring approximately 3 weeks after injury with EMG findings demonstrating loss of conduction/denervation. Operative exploration could also be considered in cases of atraumatic axillary nerve dysfunction with no evidence of clinical or EMG improvement after 6 months of conservative treatment. Referral to neurology (Choice D) is not necessary for management of Parsonage Turner syndrome, which is a type of peripheral neuropathy.

What is the most likely outcome of this patient’s condition at 1 year after the onset of symptoms if treated conservatively?

1. Complete recovery

2. Progressively improving symptoms

3. Progressively worsening symptoms

4. Loss of function of the left upper extremity

 

Discussion

The correct answer is (B). At 1 year after onset of symptoms, the patient is most likely to be in the recovery process but with ongoing weakness and/or pain. However, by 3 years most patients have fully recovered with conservative management alone. Should symptoms be progressively worsening at 1 year (Choice C), alternate explanations must be considered.

 

Objectives: Did you learn...?

 

 

Recognize the clinical presentation of a patient with axillary neuropathy? Understand the etiology of axillary neuropathy?

 

Treat a patient with axillary neuropathy?