What is the differential diagnosis for a patient presenting with elbow pain, weakness, and tingling sensation extending through the arm?

Differential Diagnosis for Elbow Pain with Weakness and Tingling

The primary differential diagnosis for a patient presenting with elbow pain, weakness, and tingling extending through the arm includes cubital tunnel syndrome (ulnar nerve compression), radial tunnel syndrome (radial nerve compression), pronator syndrome (median nerve compression), medial epicondylitis, lateral epicondylitis, cervical radiculopathy, and less commonly, olecranon bursitis or elbow sprain with associated nerve irritation.

Neurologic Causes (Most Likely Given Tingling and Weakness)

Cubital Tunnel Syndrome

• Most common nerve entrapment after carpal tunnel syndrome, affecting up to 5.9% of the general population 1
• Classic presentation includes numbness and tingling in the ring and small fingers, with pain radiating along the dorsoulnar hand 1
• Motor symptoms manifest as hand weakness, clumsiness, and in chronic cases, atrophy of the first dorsal interosseous muscle 1
• Older patients typically present with chronic motor symptoms, while younger patients have more acute presentations 1
• Physical examination findings include positive Tinel's sign at the medial elbow, positive flexion-compression test, and palpable thickening of the ulnar nerve 1
• Point tenderness at the medial elbow is common 1

Radial Tunnel Syndrome (Deep Radial Nerve Entrapment)

• Presents with lateral elbow pain combined with signs of nerve entrapment 2
• Characterized by reduction in passive range of motion during neural tension testing 2
• Often attributed to repetitive activities such as extensive keyboard work 2
• Can mimic lateral epicondylitis but distinguished by positive neural tension signs 2

Pronator Syndrome (Median Nerve Compression)

• Can occur simultaneously with cubital tunnel syndrome, particularly in manual workers 3
• Presents with resting pain in the proximal forearm and sudden onset of numbness 3
• Important caveat: Nerve conduction studies may only show positive findings for cubital tunnel syndrome even when both nerves are compressed 3
• Requires careful evaluation of symptom patterns and thorough clinical examination for accurate diagnosis 3

Cervical Radiculopathy

• Must be considered when pain and tingling extend through the arm 4
• Distinguished from peripheral nerve entrapment by dermatomal distribution and neck symptoms

Musculotendinous Causes

Medial Epicondylitis (Golfer's Elbow)

• Presents with medial elbow pain, particularly with repetitive wrist flexion and forearm pronation 5
• Can have associated paresthesias if there is secondary ulnar nerve irritation 5
• Radiographs should be obtained initially to exclude other pathology 5

Lateral Epicondylitis (Tennis Elbow)

• Lateral elbow pain that can be confused with radial tunnel syndrome 2
• Typically lacks significant neurologic symptoms unless nerve entrapment coexists 2

Elbow Sprain

• Usually follows trauma or repetitive stress 6
• May have associated ligament injury detectable on stress radiographs 6
• Neurologic symptoms suggest concomitant nerve injury 6

Other Considerations

Olecranon Bursitis

• Presents with posterior elbow swelling and pain 7
• Typically lacks significant tingling or weakness unless there is secondary nerve compression 7

Fracture or Intra-articular Pathology

• Initial radiographs are essential to exclude fractures, heterotopic ossification, osteochondral lesions, or loose bodies 8
• Joint effusion on radiographs (anterior and posterior fat pad elevation) suggests occult fracture 8
• Comparison views with the contralateral elbow are often useful 8

Diagnostic Approach

Initial Evaluation

• Obtain plain radiographs first to exclude fracture, dislocation, heterotopic ossification, or arthritis 8
• Perform specific physical examination maneuvers: Tinel's sign at cubital tunnel, flexion-compression test, neural tension testing 1, 2
• Assess specific patterns of paresthesia: ulnar distribution (ring/small fingers) versus radial distribution versus median distribution 1, 3
• Evaluate for point tenderness along nerve courses and at epicondyles 1

Advanced Imaging

• MRI without contrast may be considered if radiographs are normal and soft tissue pathology (tendon, ligament, or nerve) is suspected 8, 6
• Ultrasound can visualize nerve thickening and aid in diagnosis of nerve entrapment 1

Electrodiagnostic Studies

• Nerve conduction studies help localize the site and quantify the grade of compression 4
• Useful adjunct to clinical examination but may miss concurrent nerve compressions 3

Critical Pitfalls to Avoid

• Do not assume a single diagnosis: Simultaneous compression of median and ulnar nerves can occur, particularly in manual workers 3
• Do not rely solely on nerve conduction studies: They may be positive for only one nerve even when multiple nerves are compressed 3
• Chronic ulnar nerve compression, if left untreated, leads to irreversible muscle atrophy and significant functional impairment 1
• Neural tension testing may reveal nerve entrapment even when standard examination is unremarkable 2