What is the best course of treatment for a patient with left shoulder pain radiating to the head, sleep disturbance, and a history of pre-diabetes, who is currently on Metformin?

Management of Left Shoulder Pain with Cervical Radiation and Sleep Disturbance in a Patient with Pre-Diabetes

This patient requires immediate referral to physiotherapy for individually tailored graded exercise therapy combined with cervicothoracic spine mobilization, alongside optimization of sleep hygiene and continuation of metformin for pre-diabetes management. 1, 2

Primary Musculoskeletal Management

Immediate Physiotherapy Referral

• Refer to physiotherapy for a structured exercise program including range of motion, stretching, and progressive strengthening exercises, as therapeutic exercise demonstrates significant positive effects on both pain and function in shoulder conditions 2, 3
• Include cervicothoracic spine manipulation and mobilization in the treatment plan, as this patient's pain radiates to the neck and back of head, indicating cervicothoracic involvement 2
• Consider multimodal care combining heat/cold application, joint mobilization, and range of motion exercises, which shows effectiveness for shoulder pain of any duration 2
• Low-level laser therapy should be considered as an adjunctive treatment option for shoulder pain 2

Clinical Reasoning for Exercise-Based Approach

The limited shoulder abduction (<90 degrees), pain on flexion/extension, and positive internal rotation against resistance suggest rotator cuff involvement, but these findings do not preclude successful treatment with repeated end-range movements and progressive exercise 4. Despite positive impingement signs, exercise-based interventions remain first-line treatment 3.

Diabetes-Related Shoulder Considerations

• Rule out adhesive capsulitis (frozen shoulder), which occurs more frequently in diabetic patients and presents with severe limitation of both active and passive glenohumeral motion, particularly external rotation 5
• This patient's preserved external rotation and relatively acute 2-month duration make frozen shoulder less likely, but monitor for progression 5
• Calcific periarthritis should remain on the differential, though it typically has better prognosis than frozen shoulder 5

Sleep Disturbance Management

Direct Sleep Intervention

• Provide education on sleep hygiene practices immediately, including maintaining consistent sleep-wake times, optimizing bedroom environment, and avoiding stimulants before bedtime 1
• Inquire specifically about nocturnal pain patterns and whether pain awakens the patient or prevents sleep onset, as this guides positioning strategies 1
• Consider nighttime positioning modifications to reduce shoulder stress during sleep (avoid sleeping on affected side)

Address Underlying Pain Contributing to Sleep Disruption

• The nocturnal arm numbness/tingling and finger paresthesias suggest possible nerve compression that worsens with positioning at night 1
• If sleep disturbance persists despite addressing pain and implementing sleep hygiene, refer to a specialized sleep clinic or therapist trained in sleep restoration 1

Pre-Diabetes and Metformin Management

Continue Current Metformin Therapy

• Continue metformin as prescribed for this patient with pre-diabetes, as he is already established on therapy 6
• Monitor vitamin B12 levels periodically, especially given the presence of occasional numbness/tingling in the left arm, as metformin can cause B12 deficiency that manifests as peripheral neuropathy 1, 6
• Perform annual diabetes screening with HbA1c or fasting glucose to monitor for progression to diabetes 6

Lifestyle Modification Emphasis

• Strongly emphasize that intensive lifestyle modification (≥150 minutes/week physical activity, calorie restriction) remains first-line therapy and shows greater long-term benefit than metformin alone 6
• Address the recent job redundancy as a potential barrier to physical activity and contributor to stress-related pain amplification 1
• Metformin should complement, not replace, comprehensive lifestyle changes 6

Psychosocial Factors and Recent Job Loss

Screen for Psychological Contributors

• Assess for depression, anxiety, and catastrophizing cognitions related to the recent redundancy, as psychosocial factors can interfere with effective pain management and functional status 1
• If fear of movement or catastrophizing underlies sedentary behavior, consider multidisciplinary intervention including cognitive-behavioral therapy 1
• The recent job loss may contribute to both physical deconditioning and psychological distress that amplifies pain perception 1

Social Support Considerations

• If social variables interfere with recovery, consider referral to social worker or self-management support program 1
• Address potential financial barriers to treatment given recent redundancy 1

Monitoring and Reassessment

Short-Term Follow-Up (2-3 Weeks)

• Reassess at each visit for worsening symptoms, new neurological signs, or satisfactory recovery 2
• Monitor for progression of numbness/tingling, which could indicate nerve compression requiring different management 2
• Evaluate adherence to exercise program and barriers to implementation 1

Red Flags Requiring Urgent Reassessment

• Development of constant numbness or motor weakness in the arm 2
• Worsening pain despite appropriate conservative management 2
• Progressive loss of shoulder motion suggesting evolving adhesive capsulitis 5
• New chest pain or shortness of breath (though currently absent, monitor given cardiovascular risk from pre-diabetes) 1

Interventions to Avoid

Ineffective Modalities

• Do not offer ultrasound, taping, interferential current therapy, or soft tissue massage alone, as these lack evidence for effectiveness in shoulder pain 2
• Avoid shock-wave therapy for non-calcific shoulder pain 2
• Do not delay active treatment with prolonged passive modalities 2

Common Pitfalls to Avoid

• Do not attribute all symptoms to shoulder pathology alone—the cervical radiation pattern requires cervicothoracic assessment and treatment 2
• Do not overlook the B12 deficiency risk in this metformin-treated patient presenting with paresthesias 1, 6
• Do not underestimate the impact of recent job loss on pain perception, recovery trajectory, and ability to engage in treatment 1
• Do not prescribe metformin for pre-diabetes prevention alone without emphasizing that lifestyle modification is superior and primary 6, 7