What are the symptoms and treatment options for suprascapular neuropathy?

Suprascapular Neuropathy: Clinical Presentation and Management

Primary Clinical Symptoms

Suprascapular neuropathy presents with deep, aching shoulder pain that is poorly localized, often accompanied by visible atrophy of the supraspinatus and/or infraspinatus muscles and weakness in shoulder abduction and external rotation. 1, 2

Pain Characteristics

• Deep, poorly localized shoulder pain that may radiate to the lateral arm 1
• Pain typically worsens with overhead activities and repetitive shoulder motion 2, 3
• Intractable shoulder pain that fails to respond to standard analgesics 3
• Pain may occur even with negative electrodiagnostic studies 1

Motor Deficits

• Weakness in forward flexion of the shoulder (supraspinatus involvement) 1
• Weakness in external rotation of the shoulder (infraspinatus involvement) 1, 4
• Subjective sensation of shoulder weakness reported by patients 3
• Progressive weakness in overhead athletic activities, particularly in volleyball, tennis, swimming, and weight lifting 2, 3

Visible Muscle Changes

• Atrophy of the infraspinatus muscle (isolated spinoglenoid notch compression) 1, 2
• Atrophy of both supraspinatus and infraspinatus muscles (suprascapular notch compression) 1, 3, 4
• Visible wasting may be bilateral in rare cases 4

Etiologic Mechanisms

Compression Causes

• Ganglion cysts arising from labral or capsular tears are increasingly recognized as a primary cause of nerve compression 1, 2, 5
• Space-occupying lesions at the suprascapular notch or spinoglenoid notch 1, 2
• Hypertrophic transverse scapular ligament causing entrapment 3

Traction Injuries

• Repetitive overhead activities in athletes (volleyball, tennis, swimming, weight lifting) 2, 3
• Chronic overhead athletics causing nerve stretch 5
• Retraction of large rotator cuff tears pulling on the nerve 1, 5

Diagnostic Approach

Clinical Examination Findings

• Visible atrophy of supraspinatus and/or infraspinatus muscles on inspection 3, 4
• Weakness on manual muscle testing of shoulder abduction and external rotation 1, 4
• Temporary pain relief with diagnostic injection of local anesthetic at the suprascapular notch 3

Imaging Studies

• MRI is the preferred modality to assess rotator cuff muscle atrophy and identify compressive lesions (ganglion cysts, masses) 1, 2
• MRI provides anatomic demonstration of nerve entrapment and muscle atrophy 2
• Ganglion cysts are recognized with increasing frequency on MRI as sources of external compression 2

Electrodiagnostic Testing

• Electromyography (EMG) and nerve conduction velocity studies remain the gold standard for confirmation 1
• EMG may show denervation of suprascapular muscles and axonal loss 4
• Important caveat: Nerve pain may occur even with negative EMG findings 1
• Many overhead athletes show electrodiagnostic abnormalities without clinically relevant functional deficits 5

Treatment Algorithm

Initial Conservative Management (First 6 Months)

• Activity modification with avoidance of precipitating overhead activities 1, 2, 3
• Physical therapy focused on shoulder rehabilitation 1, 2, 3
• Nonsteroidal anti-inflammatory drugs (NSAIDs) for pain control 1, 3
• Rest from aggravating sports or occupational activities 3

Indications for Surgical Intervention

Surgery is indicated when:

• Conservative treatment fails after 6 months 3
• A discrete compressive lesion (ganglion cyst, mass) is identified on MRI 2, 3, 5
• Progressive weakness or atrophy develops despite conservative measures 1, 2

Surgical Approach

• Decompression of the suprascapular nerve via excision of the transverse scapular ligament 3, 4
• Arthroscopic surgical approaches have become more common than open techniques 1
• Cyst excision when ganglion cysts are the compressive source 2, 5

Expected Outcomes

Pain Relief

• Surgical decompression provides reliable pain relief 2
• Patients typically become symptom-free within 6 weeks to 6 months postoperatively 3, 4

Functional Recovery

• Recovery of shoulder function may be incomplete, particularly with long-standing compression 2
• Restoration of atrophied muscle tissue is often incomplete 2
• Return to sport is possible after intensive postoperative rehabilitation in well-indicated patients 3, 5

Critical Clinical Pitfalls

• Do not overlook suprascapular neuropathy as a diagnosis in patients with shoulder pain and weakness, as it may be more common than historically believed 1
• Do not rely solely on EMG for diagnosis, as nerve pain can occur with negative electrodiagnostic studies 1
• Do not delay MRI when clinical suspicion exists, as it identifies treatable compressive lesions 1, 2
• Do not rush to surgery in overhead athletes with electrodiagnostic abnormalities but no clinically relevant functional deficits 5
• Suprascapular neuropathy should be considered in any patient with shoulder pain, particularly those with visible atrophy of the supraspinatus and infraspinatus muscles 4